Average Cell Volume Research Articles

Electrochemical performances of activated carbon prepared using eggshell waste

This paper describes the preparation of activated carbon (Ac) from broiler hen eggshell (BES) and Country hen eggshell (CES) waste with the assistance of chemical activating agent orthophosphoric acid (H3PO4) and eggshell powder for 4:1 and 4:2 concentrations. XRD analysis affirmed the formation of Ac and the hexagonal structure of CaCO3 for both BES and CES samples. The average crystalline size, dislocation density, microstrain, lattice parameter, and cell volume values are found to be higher for CES. The FTIR spectra confirmed the presence of functional groups of BES and CES samples of Ac. UV-DRS spectra exhibited strong absorption in the visible region for BES and the bandgap value is found to be around 1.2 eV for both BES and CES. The surface morphology reveals the porous nature, irregular shape and uniform size particles of Ac. Cyclic voltammetry and electrochemical impedance spectroscopy measurements were performed to study the energy storage application. Though both BES and CES have showed the capacitive behavior, the sample BES exhibit higher specific capacitance of 155.8 F/g is achieved for BES than CES. Similarly, the Rs and Rct values are calculated from the impedance measurement and it is found to be lower for BES sample that indicates improved electrical conductivity.

Hemocytopoiesis and microelements metabolism’s indices in calves under the infl uence of national vitamin-amino-acid complex

In Ukrainian veterinary medicine the study of the eff ectiveness of new complex drugs remains relevant. The eff ect of the vitamin-mineral complex "Alphabet for Animals" on the state of hemocytopoiesis and the microelements metabolism in calves of 1.5‒2.5 months of age were studied. The composition of this drug includes the biologically active substances: vitamins A, D3, E, B1, B3, B5, B6, B12, K3 and essential amino-acids: DL-methionine, L-lysine and arginine. It is used in farm animals and poultry for the normalization of hemocytopoiesis, the prevention and treatment of vitamins and trace elements metabolism’s disorders. In the fi rst week of drug administration, the number of erythrocytes in the experimental animals group has increased signifi cantly (p<0.05) and after its second feeding, the positive eff ect on erythrocytopoiesis in calves has became even greater (p<0.001), compared to the calves in control group. The level of hemoglobin in calves of experimental group also increased signifi cantly from the beginning of the drug to the end of the experiment, whereas in calves of the control group there was a tendency to decrease its level throughout the all experiment. The color index and erythrocyte saturation by hemoglobin (MCH) at the fi rst and second blood samples were signifi cantly decreased (p<0.05) in control calves group, whereas in animals of experimental group there was no signifi cant diff erence between these parameters (p<0.1). The average volume of red blood cells did not diff er between control and test calves during the experiment (p<0.1). Under the drugs infl uence the Ferum blood content in calves of experimental group increased by 24.2 %. In the control calves group, this tendency was not so noticeable (the increase of Ferum serum level at the end of experiment was only +7.8 % (p<0.1), compared to the initial indices). The Zinc metabolism, on the contrary, has not undergone signifi cant changes. The Cuprum serum level in experimental calves group remained always signifi cantly higher than in control animals group. “Alphabet for Animals” has a positive eff ect on hemocytopoiesis in calves due to its complex composition (fat-soluble and water-soluble vitamins, aminoacids) and improves the metabolism of microelements, including Ferum and Cuprum. The infl uence on these processes the vitamins of B group, which are a part of this drug, we consider especially valuable in the conditions of the unformed rumen digestion in young cattle. Key words: vitamin-amino acid complex, erythrocytopoiesis, hypochromia, microcytosis, hemoglobin, color index, hematocrit.

Generalized size scaling of metabolic rates based on single-cell measurements with freshwater phytoplankton

Kleiber's law describes the scaling of metabolic rate with body size across several orders of magnitude in size and across taxa and is widely regarded as a fundamental law in biology. The physiological origins of Kleiber's law are still debated and generalizations of the law accounting for deviations from the scaling behavior have been proposed. Most theoretical and experimental studies of Kleiber's law, however, have focused on the relationship between the average body size of a species and its mean metabolic rate, neglecting intraspecific variation of these 2 traits. Here, we propose a theoretical characterization of such variation and report on proof-of-concept experiments with freshwater phytoplankton supporting such framework. We performed joint measurements at the single-cell level of cell volume and nitrogen/carbon uptake rates, as proxies of metabolic rates, of 3 phytoplankton species using nanoscale secondary ion mass spectrometry (NanoSIMS) and stable isotope labeling. Common scaling features of the distribution of nutrient uptake rates and cell volume are found to hold across 3 orders of magnitude in cell size. Once individual measurements of cell volume and nutrient uptake rate within a species are appropriately rescaled by a function of the average cell volume within each species, we find that intraspecific distributions of cell volume and metabolic rates collapse onto a universal curve. Based on the experimental results, this work provides the building blocks for a generalized form of Kleiber's law incorporating intraspecific, correlated variations of nutrient-uptake rates and body sizes.

ESTIMATION OF HEMOGRAMS INDICES IN PERSONS OF THE ORGANIZED GROUP IN EXTREME CONDITIONS WHEN IN THE DIET INCLUDED PRODUCTS PRODUCED BY CRYOGENIC TECHNOLOGY

We estimated the hemograms indices of the schoolstudents’ blood enrolled a high military educational institution. By cryogenic technology produced products from protein-vegetable (first) or vegetable raw materials (second) were introduced into the diet of the two main groups. The comparison group was the third one. The blood samples study was performed three times: in the initial state, after taking the product and after 30 days of observation. The average red blood cell volume increased in all examined patients indicating a compensatory reaction of the body to the load, the growth one was less significant in the main groups. The average hemoglobin content in the red blood cell in the first group did not change by stages of observation, in the second and third groups it was decreased by the end of observation. The average hemoglobin concentration decreased, it was less in the main groups. We noted an increase in the number of lymphocytes by 20.7 %, (p = 0.0001) and an increase in the indicator of a mixture from monocytes, basophils, eosinophils when taking the first product. An increase in the number of lymphocytes was noted in the second and third groups only by the end of the observation. The relative lymphocytes content when taking the first product was more significant in the second and third stages of observation than in the initial state; in the second one it was by the end of the observation. The relative neutrophils content in the first group decreased by the end of reception, in the second one it was by the end of observation; in the comparison group remained unchanged. The average platelets volume have been decreased in the first and control groups by the end of the observation and in the second group by the end of taking the product. The relative width of the platelets distribution by volume and the coefficient of large platelets have been decreased in individuals of the group, which may have a positive effect on blood clotting. Thus, the influence of adaptation factors in the main groups was less significant than in the comparison group.

Effects of Elevated CO2 on a Natural Diatom Community in the Subtropical NE Atlantic

Diatoms are silicifying phytoplankton contributing about one quarter to primary production on Earth. Ocean acidification (OA) could alter the competitiveness of diatoms relative to other taxa and/or lead to shifts among diatom species. In spring 2016, we set up a plankton community experiment at the coast of Gran Canaria (Canary Islands, Spain) to investigate the response of subtropical diatom assemblages to elevated seawater pCO2. Therefore, natural plankton communities were enclosed for 32 days in in situ mesocosms (∼8 m3 volume) with a pCO2 gradient ranging from 380 to 1140 μatm. Halfway through the study we added nutrients to all mesocosms (N, P, Si) to simulate injections through eddy-induced upwelling which frequently occurs in the region. We found that the total diatom biomass remained unaffected during oligotrophic conditions but was significantly positively affected by high CO2 after nutrient enrichment. The average cell volume and carbon content of the diatom community increased with CO2. CO2 effects on diatom biomass and species composition were weak during oligotrophic conditions but became quite strong above ∼620 μatm after the nutrient enrichment. We hypothesize that the proliferation of diatoms under high CO2 may have been caused by a fertilization effect on photosynthesis in combination with reduced grazing pressure. Our results suggest that OA in the subtropics may strengthen the competitiveness of (large) diatoms and cause changes in diatom community composition, mostly under conditions when nutrients are injected into oligotrophic systems.

Железодефицитные синдромы в клинической онкологии и их коррекция препаратами нутритивного действия

In the literature there is little information about the occurrence of dielectrolytes with inadequately selected parenteral-enteral correction. This fully applies to the correction of iron deficiency in colorectal cancer (CRC). Material and methods. On examination were 51 patients with CRC (T3N1M0 and T4N0M1) and iron deficiency of various severity. Nutritional status was assessed by the parameters of a known alimentary-volemic diagnosis (AED). Iron deficiencies resulting from chronic blood loss were assessed by the content of serum iron, ferritin, transferrin, the level of Hb and Ht, the number and average volume of red blood cells, and the average content of Hb in the red blood cell. The control group consisted of 10 patients with iron-deficient anemia. Results. One of the components of the AVD is the determination of electrolyte deficiencies, including gland. With a deficit of free iron in plasma up to 11%, a decrease in hemoglobin level and Ht, a slight decrease in the number of erythrocytes and normal parameters of ferritin, the average volume of erythrocyte and the content of Hb in it were sufficient nutritive correction mixtures containing 3.0-3.5 mg of iron in 100 g dry product. With a higher iron deficiency, additional parenteral administration of its drugs was required: as part of the nutritional correction, as a pharmacological supplement, supplements were injected with non-sorbed or sorbed iron on a special matrix (ironMatrix), which guaranteed the stability of the iron complex and its controlled release in the body. At the same time, sorbed iron provided a higher safety (no complications were observed in any of the studies. with the administration of non-sorbed iron in 2 cases, there were unpleasant sensations in the heart area, in the right hypochondrium, resembling signs of iron overload (ferritin could increase to 1340 mg), stopped, however, only by the administration of a hepatoprotector and 0.9% of the sodium chloride solution without the additional use of an antidote. Conclusion. For the sake of safety of iron deficiency correction (prevention of toxic-metabolic complications) when conducting a comprehensive nutritional correction in patients with CRC complicated by mild chronic anemia with iron deficiency not more than 11%, it is advisable to use drugs containing iron (3-3.5 mg per 100 g of dry product), and in case of a pronounced shortage of it, supplement the nutritional support with parenteral preparations of sorbed iron under the control of the parameters of iron metabolism.

Suitability of Raman Spectroscopy for Assessing Anisotropic Strain in Thin Films of Doped Ceria

AbstractA protocol for characterizing relaxation of anisotropic strain in thin films of 10 mol% Eu‐ or Sm‐doped ceria is described. The method is based on comparison of Raman spectra and X‐ray diffraction patterns from substrate‐supported films, displaying in‐plane compressive strain (initial state), with analogous data from 2 mm diameter self‐supported films (i.e., membranes), prepared by partial substrate removal (final state). These membranes are found to be relaxed, i.e., approximately unstrained, but with increased unit cell volume. The effective (i.e., 2‐state) Grüneisen parameter of the F2g Raman active mode for these films is calculated to be 0.4 ± 0.1, which is ≈30% of the literature value for the corresponding ceramics under isostatic pressure. On this basis, it is found that the observed red‐shift of the F2g mode frequency following isothermal strain relaxation of the doped ceria thin films cannot be determined solely by the increase in average unit cell volume. The study presented here may shed light on the suitability of Raman spectroscopy as a technique for characterizing strain in lanthanide‐doped ceria thin films.

Seasonal dynamics of phytoplankton morphological characters and driving factors in tropical reservoirs: A case study from Gaozhou Reservoir

体积、比表面积和最大轴性长度是浮游植物主要的形态性状，反映浮游植物资源竞争和反牧食能力.群落中物种的性状分布会随着环境条件的季节改变而变化，热带水库环境条件的季节性变化小，可能导致群落形态性状变化不显著.本文以热带大型水库——高州水库为研究对象，分析浮游植物形态性状季节动态及关键影响因子.高州水库浮游植物以丝状和单细胞藻类为主，群落水平的平均细胞体积在108.52~753.25 μm³之间，平均比表面积在0.93~2.08 μm^-1之间，平均最大轴性长度在5.21~17.44 μm之间，均有明显的季节特征.浮游植物群落平均细胞体积、最大轴性长度与总氮浓度呈负相关，与水温呈正相关；平均比表面积与硝态氮浓度呈负相关.粘质长孢藻（Dolichospermum mucosa）和光角星鼓藻（Staurastrum muticum）是高州水库浮游植物优势种，其形态性状均具有明显的时空差异，表现出明显的形态可塑性.粘质长孢藻的平均细胞体积、最大轴性长度与总氮浓度呈正相关，与水温呈负相关；平均比表面积与总氮浓度呈负相关，与水温呈正相关.光角星鼓藻的平均细胞体积、最大轴性长度与正磷酸盐浓度呈正相关.总体上高州水库浮游植物在群落和种群水平形态性状均有明显的季节差异，夏季以大细胞为主，其他季节以小细胞种类为主，水温、氮和磷的可利用性是导致浮游植物形态性状季节差异的关键因子.;Volume, specific surface area and the longest axial linear dimension are main morphological characters of phytoplankton. These characters reflect the ability of phytoplankton in competing for resources and resisting grazing. The morphological characters of cells change with the seasonal environmental conditions. It was assumed that limited seasonal changes occurred on phytoplankton cells morphological characters in community, due to the small seasonal variation of environmental conditions in tropical reservoirs. To test this assumption, the seasonal dynamic of phytoplankton morphological characters and the affecting factors in large tropical reservoir (Gaozhou Reservoir)were analyzed. The phytoplankton community was dominated by filamentous species and unicellular algae in Gaozhou Reservoir. In community level, the average cell volume was 108.52-753.25 μm³, the average cell specific surface area was 0.93-2.08 μm^-1, the average cell longest axial linear dimension was 5.21-17.44 μm, and the three morphological characters all showed seasonal dynamics. The average cell volume and the average cell longest axial linear dimension were correlated negatively with total nitrogen, and positively with temperature, the average cell specific surface area was correlated negatively with nitrate nitrogen. Dolichospermum mucosa and Staurastrum muticum were the dominant phytoplankton species in Gaozhou Reservoir, and they both showed morphological plasticity and seasonal dynamics in the morphological characters. The average cell volume and the average cell longest axial linear dimension of D. mucosa were correlated positively with total nitrogen, and negatively with temperature. The average cell specific surface area of D. mucosa was correlated negatively with total nitrogen, and positively with temperature. The average cell volume and the average cell longest axial linear dimension of S. muticum were correlated positively with soluble reactive phosphate. In conclusion, the morphological characters of phytoplankton in community and species were different with seasonal dynamics in Gaozhou Reservoir. The large cells dominated phytoplankton community in summer, but small cells in other season. Temperature, the availability of nitrogen and phosphorus were the primary factors to explain the morphological variation of phytoplankton.

Стан системи гемостазу за трансмісивної венеричної саркоми собак

Стан системи гемостазу за трансмісивної венеричної саркоми собак

Зв'язок показників кисневмісних елементів крові з тривалістю систематичних занять триатлоном у спортсменів-аматорів

Purpose: to investigate the nature of changes in the indicators of oxygen-containing blood elements in amateur athletes with different duration of systematic triathlon training. Material & Methods: peripheral blood taken from 96 physically active men examined was considered as an object of study. Indicators of oxygen-containing blood elements were determined using an automatic hematological analyzer. (MicroCC-20 Plus, США). Results: amateur athletes showed a link between the duration of regular triathlon classes and red blood indicators, in particular, a significant increase in the content of red blood cells and hematocrit was shown in the sixth month of triathlon training for non-athletes. Revealed a significant decrease in the average red blood cell volume in the blood of amateur athletes for 12 months of triathlon training compared to untrained individuals. Conclusion: most pronounced changes in oxygen-containing blood parameters are observed in amateur athletes in the first 4–6 months and depend on the duration of systematic aerobic exercise. With the duration of systematic classes of 1 year, there is a stabilization of indicators, which may be associated with the achievement of the optimal level of functioning of the blood system. The decrease in oxygen-containing blood parameters during long periods of systematic training may be associated with inadequate intensity of training loads or intense competitive activity.

The diagnostic value of PLASMIC score in the discrimination between thrombotic thrombocytopenic purpura and disseminated intravascular coagulation

目的比较PLASMIC积分在血栓性血小板减少性紫癜（TTP）和弥散性血管内凝血（DIC）患者中的差异，评价该积分系统对于两种疾病鉴别诊断的临床价值。方法回顾性分析24例TTP和41例DIC患者的临床资料，以及血小板计数、平均红细胞体积、间接胆红素、肌酐和凝血酶原时间-国际标准化比值，统计PLASMIC积分。结果根据PLASMIC积分预测伴有ADAMTS13严重缺乏的TTP的危险度分层，24例TTP患者中，3例（12.5%）存在中度风险，21例（87.5%）存在高度风险。而在41例DIC患者中，38例（92.7%）存在低度风险，2例（4.9%）存在中度风险，仅有1例（2.4%）患者存在高度风险。在65例患者中，PLASMIC积分达高度风险对于TTP诊断的敏感性为87.5%，特异性为97.6%。结论PLASMIC积分系统高度风险的患者诊断为TTP的可能性大。该积分系统对于TTP和DIC的鉴别诊断有较高的临床价值。

БИОХИМИЧЕСКИЕ И МОРФОМЕТРИЧЕСКИЕ ПОКАЗАТЕЛИ НЕКОТОРЫХ ОРГАНОВ И ТКАНЕЙ ГИБРИДА ТИЛЯПИИ (OREOCHROMIS SPP.) ПРИ ВЫРАЩИВАНИИ С ИСПОЛЬЗОВАНИЕМ ПРЕПАРАТА ЭС-2

The article studies the effect of addition into the feed of Sapropel extract (ES-2 preparation) on the intensity of lipid peroxidation in the liver and gills of hybrid tilapia ( Oreochromis spp. ), as well as on the morphofunctional state of its liver. Sapropel extract caused a decrease in the content of TBA-reactants in the tissues of tilapia liver by 17% compared to the control group. In gills the bioadditive resulted in the increased content of peroxide products by 24%. The introduction of ES-2 in fish feed resulted in reduction of spontaneous and ascorbate-dependent lipid peroxidation rate in the liver by 18%. In the gills of fish, under the influence of Sapropel, the rate of spontaneous lipid peroxidation increased by 27%, the rate of ascorbate-dependent lipid peroxidation - by 23%. The change in the intensity of peroxide processes under the influence of the fodder additive in fish organs is tissue-specific: antioxidant effect was recorded in the liver, prooxidant effect was observed in the gills. The introduction of the Sapropel extract does not lead to a change in the volume of liver nuclei in the test groups of tilapia, while the average cell volume in the experimental group was 37% lower than in the control group. The decrease in cell volume led to the increase in the nuclear-cytoplasmic ratio by 1.9 times in the experimental group compared to the control group. Hepatocyte cytoplasm volume decrease and nuclear-cytoplasmic ratio increase due to addition of ES-2 preparation into productive feed of hybrid tilapia would indicate a rise of functional activity of liver cells.

Brain active transmembrane water cycling measured by MR isassociated with neuronal activity.

fMRI is widely used to study brain activity. Unfortunately, conventional fMRI methods assess neuronal activity only indirectly, through hemodynamic coupling. Here, we show that active, steady-state transmembrane water cycling (AWC) could serve as a basis for a potential fMRI mechanism for direct neuronal activity detection. AWC and neuronal actitivity in rat organotypic cortical cultures were simultaneously measured with ahybrid MR-fluorescence system. Perfusion with a paramagnetic MRI contrast agent, Gadoteridol, allows NMR determination of the kinetics of transcytolemmal water exchange. Changes in intracellular calcium concentration, [Cai2+ ] were used as a proxy of neuronal activity and were monitored by fluorescence imaging. When we alter neuronal activity by titrating with extracellular [K+ ] near thenormal value, we see an AWC response resembling Na+ -K+ -ATPase (NKA) Michaelis-Menten behavior. When we treat with thevoltage-gated sodium channel inhibitor, or with an excitatory postsynaptic inhibitor cocktail, we see AWC decrease by up to 71%. AWC was found also to be positively correlated with the basal level of spontaneous activity, which varies in different cultures. These results suggest that AWC is associated with neuronal activity and NKA activity is amajor contributor in coupling AWC to neuronal activity. Although AWC comprises steady-state, homeostatic transmembrane water exchange, our analysis also yields a simultaneous measure of the average cell volume, which reports any slower nettransmembrane water transport.

Cell tension and mechanical regulation of cell volume

Animal cells use an unknown mechanism to control their growth and physical size. Here, using the fluorescence exclusion method, we measure cell volume for adherent cells on substrates of varying stiffness. We discover that the cell volume has a complex dependence on substrate stiffness and is positively correlated with the size of the cell adhesion to the substrate. From a mechanical force–balance condition that determines the geometry of the cell surface, we find that the observed cell volume variation can be predicted quantitatively from the distribution of active myosin through the cell cortex. To connect cell mechanical tension with cell size homeostasis, we quantified the nuclear localization of YAP/TAZ, a transcription factor involved in cell growth and proliferation. We find that the level of nuclear YAP/TAZ is positively correlated with the average cell volume. Moreover, the level of nuclear YAP/TAZ is also connected to cell tension, as measured by the amount of phosphorylated myosin. Cells with greater apical tension tend to have higher levels of nuclear YAP/TAZ and a larger cell volume. These results point to a size-sensing mechanism based on mechanical tension: the cell tension increases as the cell grows, and increasing tension feeds back biochemically to growth and proliferation control.

Mutant monocyte chemoattractant protein-1 protein (7ND) inhibits osteoclast differentiation and reduces oral squamous carcinoma cell bone invasion.

The seven-amino acid truncated (7ND) protein is an N-terminal deletion mutant of monocyte chemoattractant protein-1 (MCP-1) and it functions as a dominant-negative inhibitor. 7ND and wild-type MCP-1 form a heterodimer, which binds to MCP-1 receptors and inhibits monocyte chemotaxis. In the present study, the 7ND protein was cloned, expressed and purified. An MTT assay revealed that the proliferation of oral squamous cell carcinoma (OSCC) SCC25 cells was not affected following 3 days of treatment with synthetic 7ND protein. Serial dilutions of the 7ND protein were tested for monocyte migration and osteoclast differentiation, and tartrate-resistant acid phosphatase staining demonstrated that significantly fewer osteoclasts were differentiated from cluster of differentiation 14+ (CD14+) monocytes using magnetic activated cell sorting. Immunofluorescence confirmed these results and significantly less F-actin staining was observed in 7ND-treated osteoclasts. Furthermore, bone invasion was examined by subcutaneously injecting SCC25 cells into the area overlaying the calvariae of nude mice. The results demonstrated that the average tumor volume of SCC25 cells with 7ND protein was similar to the average volume of tumors formed by untreated SCC25 cells. Flow cytometric analysis suggested that the CD14+ subpopulation in the bone marrow of 7ND-treated mice was reduced compared with that of untreated mice. Micro-computed tomography imaging revealed significantly less bone resorption in the calvariae injected with SCC25 cells plus the 7ND protein. Taken together, the results of the present study demonstrated the potential therapeutic value of the 7ND protein. The 7ND MCP-1 variant not only functions in vitro to inhibit osteoclast differentiation, but also reduces the progression of bone invasion by OSCC cells in vivo.

A geometrically controlled rigidity transition in a model for confluent 3D tissues

The origin of rigidity in disordered materials is an outstanding open problem in statistical physics. Previously, a class of 2D cellular models has been shown to undergo a rigidity transition controlled by a mechanical parameter that specifies cell shapes. Here, we generalize this model to 3D and find a rigidity transition that is similarly controlled by the preferred surface area S0: the model is solid-like below a dimensionless surface area of with being the average cell volume, and fluid-like above this value. We demonstrate that, unlike jamming in soft spheres, residual stresses are necessary to create rigidity. These stresses occur precisely when cells are unable to obtain their desired geometry, and we conjecture that there is a well-defined minimal surface area possible for disordered cellular structures. We show that the behavior of this minimal surface induces a linear scaling of the shear modulus with the control parameter at the transition point, which is different from the scaling observed in particulate matter. The existence of such a minimal surface may be relevant for biological tissues and foams, and helps explain why cell shapes are a good structural order parameter for rigidity transitions in biological tissues.

Investigation of discrete stress distribution for dry powder compaction using Discrete Element Method and weighted Voronoi tesselation

AbstractPowder compaction of granular material plays a substantial role in the manufacturing process of ceramics industry and powder metallurgy industry. The compaction behaviour is ruled by granular flow and densification of deformable particles. Discrete element method (DEM) allows to investigate the powder compaction process numerically on the microscale by modeling the forces on the particle level and simulating the particle motion. Three‐dimensional data about particle size distribution and spatial structure of the particle packing can be extracted from micro‐computed tomography (µCT). An average stress tensor can be computed from DEM results, evaluating the contact forces and the distances from the particle center to the contact point with respect to an average cell volume. A weighted Voronoi tesselation of the polydisperse particle assembly is proposed for mapping a cell volume to each individual particle. With this approach all structural information of the particle system can be transferred from a discrete particle model to a heterogeneous volume model of micro‐structure. Discrete stress distributions for uniaxial powder compaction are presented. (© 2017 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)

The Effect of Eu Doping on Microstructure, Morphology and Methanal-Sensing Performance of Highly Ordered SnO₂ Nanorods Array.

Layered Eu-doped SnO2 ordered nanoarrays constructed by nanorods with 10 nm diameters and several hundred nanometers length were synthesized by a substrate-free hydrothermal route using alcohol and water mixed solvent of sodium stannate and sodium hydroxide at 200 °C. The Eu dopant acted as a crystal growth inhibitor to prevent the SnO2 nanorods growth up, resulting in tenuous SnO2 nanorods ordered arrays. The X-ray diffraction (XRD) revealed the tetragonal rutile-type structure with a systematic average size reduction and unit cell volume tumescence, while enhancing the residual strain as the Eu-doped content increases. The surface defects that were caused by the incorporation of Eu ions within the surface oxide matrix were observed by high-resolution transmission electron microscope (HRTEM). The results of the response properties of sensors based on the different levels of Eu-doped SnO2 layered nanoarrays demonstrated that the 0.5 at % Eu-doped SnO2 layered nanorods arrays exhibited an excellent sensing response to methanal at 278 °C. The reasons of the enhanced sensing performance were discussed from the complicated defect surface structure, the large specific surface area, and the excellent catalytic properties of Eu dopant.

Synthesis and Optical Properties of Pb Doped ZnO Nanoparticles

This article deals with the structural and optical characterization of lead-doped zinc oxide nanoparticles synthesized by precipitation method. X-ray diffraction study confirmed the substitution of Pb dopant without disturbing the basic wurtzite structure of zinc oxide. The average crystallite size, lattice constants, and unit cell volume also increased up to 10% of lead doping. The energy gap of the samples was determined from the ultraviolet-visible absorption spectrum as well as Tauc’s plot which infers that the energy gap decreases with the increase of lead content. Fourier Transformation Infra Red spectrum confirmed the lead dopant through peak shifting from 437–549cm−1. Photoluminescence spectrum also defines the leads dopant by means of intensity increase. Scanning electron microscope study also confirmed the existence of particles in nanometer size and it witnessed the microstructure transformation from nanoparticles to the rod-like structure on 10 (wt.%) lead doping.

Fast, Na+ /K+ pump driven, steady-state transcytolemmal water exchange in neuronal tissue: A study of rat brain cortical cultures.

Water homeostasis and transport play important roles in brain function (e.g., ion homeostasis, neuronal excitability, cell volume regulation, etc.). However, specific mechanisms of water transport across cell membranes in neuronal tissue have not been completely elaborated. The kinetics of transcytolemmal water exchange were measured in neuronal tissue using simultaneous, real-time fluorescence and nuclear magnetic resonance (NMR) measurements of perfused, active brain organotypic cortical cultures. Perfusion with a paramagnetic MRI contrast agent, gadoteridol, allows NMR determination of the unidirectional rate constant for steady-state cellular water efflux (kio ), and the mole fraction of intracellular water ( pi), related to the average cell volume (V). Changes in intracellular calcium concentration [Cai2+] were used as a proxy for neuronal activity and were monitored by fluorescence imaging. The kio value, averaged over all cultures (N = 99) at baseline, was 2.02 (±1.72) s-1 , indicating that on average, the equivalent of the entire intracellular water volume turns over twice each second. To probe possible molecular pathways, the specific Na+ -K+ -ATPase (NKA) inhibitor, ouabain (1 mM), was transiently introduced into the perfusate. This caused significant transient changes (N = 8): [Cai2+] rose ∼250%, V rose ∼89%, and kio fell ∼45%, with a metabolically active kio contribution probably eliminated by ouabain saturation. These results suggest that transcytolemmal water exchange in neuronal tissue involves mechanisms affected by NKA activity as well as passive pathways. The active pathway may account for half of the basal homeostatic water flux. Magn Reson Med 79:3207-3217, 2018. © 2017 International Society for Magnetic Resonance in Medicine.