Hypergravity Research Articles

Numerical investigation on laser-induced nanobubble nucleation and dynamics of plasmonic nanoparticles with different structures

The motion and heat transfer understanding of laser-induced nanobubbles generating on nanoparticles is important for solar energy utilization, medical treatment and seawater purification. Phase change lattice boltzmann method is used to simulate heat and mass transfer between liquid and vaper and momentum exchange method is used to study the nanoparticle trajectory in the fluid. Convection between the nanoparticle surface and the surrounding fluid is considered using a novel conjugated thermal boundary approach, which involves the integration of two meshes and virtual nodes. Solid and hollow nanoparticles with and without pillars are investigated to evaluate their performance in generating nanobubbles. Both the surface to vloume ratio and the absorption coefficient affect the nanobubble generation threshold under normal gravity. The hyper gravity promotes the nanobubble nucleation when nanoparticle size is more than 20 nm. Nanobubbles nucleate easily on nanoparticle with short pillar. Although hollow nanoparticles have the lower threshold for nanobubble generation, the nanobubble generating on hollow nanoparticles is less than on solid nanoparticles. The highly aggregated nanoparticles enhance the innitial nanobubble generation. However, nanoparticles with longer spacing produce more nanobubble in long term.

Numerical analysis on combustion characteristics of diffusion jet flame under different gravity environments

To study the combustion characteristics of turbulent jet flames under different gravity environments, the centerline temperature distribution curve and air entrainment rate of turbulent jet flame from microgravity to hyper gravity was carried out by CFD simulation. Five different gravity values have been considered. The simulation results show that the flame temperature decreases with the increase of gravity in the intermittent flame region and plume region. The maximum temperature decreases with the increase of gravity, while their position decreases accordingly. The evolution of air entrainment has been analyzed under different gravity environments. Based on the hydroxyl concentration distribution, a correlation of flame height has been obtained through dimensionless analysis. The evolution of air entrainment has been described under different heat release rate and gravity environments.

A Three-Dimensional Vibration Theory for Ultralight Cellular Sandwich Plates Subjected to Linearly Varying In-Plane Distributed Loads.

Thin structural elements such as large-scale covering plates of aerospace protection structures and vertical stabilizers of aircraft are strongly influenced by gravity (and/or acceleration); thus, exploring how the mechanical behaviors of such structures are affected by gravitational field is necessary. Built upon a zigzag displacement model, this study establishes a three-dimensional vibration theory for ultralight cellular-cored sandwich plates subjected to linearly varying in-plane distributed loads (due to, e.g., hyper gravity or acceleration), with the cross-section rotation angle induced by face sheet shearing accounted for. For selected boundary conditions, the theory enables quantifying the influence of core type (e.g., close-celled metal foams, triangular corrugated metal plates, and metal hexagonal honeycombs) on fundamental frequencies of the sandwich plates. For validation, three-dimensional finite element simulations are carried out, with good agreement achieved between theoretical predictions and simulation results. The validated theory is subsequently employed to evaluate how the geometric parameters of metal sandwich core and the mixture of metal cores and composite face sheets influence the fundamental frequencies. Triangular corrugated sandwich plate possesses the highest fundamental frequency, irrespective of boundary conditions. For each type of sandwich plate considered, the presence of in-plane distributed loads significantly affects its fundamental frequencies and modal shapes.

Study of mouse behavior in different gravity environments

Many experiments have analyzed the effect of the space environment on various organisms. However, except for the group-rearing of mice in space, there has been little information on the behavior of organisms in response to gravity changes. In this study, we developed a simple Active Inactive Separation (AIS) method to extract activity and inactivity in videos obtained from the habitat cage unit of a space experiment. This method yields an activity ratio as a ratio of ‘activity’ within the whole. Adaptation to different gravitational conditions from 1g to hypergravity (HG) and from microgravity (MG) to artificial 1g (AG) was analyzed based on the amount of activity to calculate the activity ratio and the active interval. The result for the activity ratios for the ground control experiment using AIS were close to previous studies, so the effectiveness of this method was indicated. In the case of changes in gravity from 1g to HG, the ratio was low at the start of centrifugation, recovered sharply in the first week, and entered a stable period in another week. The trend in the AG and HG was the same; adapting to different gravity environments takes time.

Effects of High g Values on Growth and Chlorophyll Content in Hydrated and Dehydrated Wheat Seeds

Higher g value stimuli (gravitational acceleration more than 1 g and referred as hyper gravity) caused by centrifugation have been shown to inhibit elongation growth of various plants. In the present study, effects of high g values were studied on wheat seeds with and without water medium at the time of exposure to high g values. Wheat seeds (variety: LOK-1) were washed with 0.5% fungicide and then 4-5 times with distilled water (D/W). Seeds were then soaked in D/W for 24 hrs. Two different experiments were performed. In initial experiment, soaked seeds were taken into the centrifuge tubes filled with 1 ml D/W. Seeds were exposed to hypergravity ranging from 500 g to 2500 g for 10 minutes. In another experiment, soaked seeds were taken into the centrifuge tubes without water or any other medium and then exposed to high g values. After exposure seeds were immediately sowed on 0.8% agar gel. Results obtained showed that exposure to high g values suppressed growth in wheat seedlings when seeds were exposed to high g values with water as a medium. Chlorophyll content also decreased with increase in g. However, no change in growth and chlorophyll content were observed when seeds were exposed without water medium up to g values as high as 2500. Thus, effects of high g value stimuli depend not only on how much centrifugal force is applied to the seeds but also depends upon how much force is experienced by the inner part of the seeds. Present observation shows that effective centrifugal force experienced by the seeds is different when applied with and without medium.

Numerical investigation on convective heat transfer of supercritical aviation kerosene in a horizontal tube under hyper gravity conditions

The present study numerically investigates the convective heat transfer characteristics of supercritical aviation kerosene in a horizontal tube under hyper gravity conditions with various gravitational accelerations. Effects of mass flow rate (1.5 g/s∼2.5 g/s) and heat flux (500 kW/m∼2700 kW/m2) on heat transfer under hyper gravity conditions are discussed. Analyses focused on the influences of buoyancy force on heat transfer characteristics of the top and bottom wall under hyper gravity conditions. The model is simplified as a horizontal tube with the diameter of 1.8 mm and the length of 250 mm. The results show that the gravity plays a dominant role and the secondary flow structure is induced due to the drastic decrease in density in the pseudo-critical region. Two types of deterioration occur when the wall temperature and bulk temperature reaches the pseudo-critical point respectively. The onset of the deterioration occurs earlier with the increase of gravitational acceleration. As the gravitational acceleration increases, the difference between the top and bottom wall heat transfer coefficient (HTC) becomes larger. The criterion Grq/Grth<1 proposed by Petukhov is proved to be applicable to evaluate the effects of buoyancy.

Effects of icariin on adhesion and cytoskeleton of osteoblasts in response to the extreme mechanical environment of hypergravity

Objective To establish a hypergravity loading model with a high-acceleration centrifugal loading device and to investigate the effects of different hypergravity loading and icariin on osteoblast adhesion and cytoskeleton. Methods MC3T3-E1 cells were seeded in the dishes of cell culture at a density of 2×105/cm2. And the experiment was divided into 6 groups: control group (without icariin and loading); simple administration group (only icariin); 10 G loading group (only loading); 10 G administration group (with icariin and loading); 40 G loading group (only loading); 40 G administration group (with icariin and loading). The experimental loading group was loaded with MC3T3-E1 cells using a high-acceleration centrifugal loader. And continuous loading for 3 d, 30 min per d. The control group and the simple administration group were exposed to normal gravity, and the remaining conditions were not different from the experimental group. Icariin was used at a concentration of 10-7 mol/L in all administration groups, and the experiments were carried out according to the method of preventive administration. At the same time, the related molecular biological techniques such as alizarin red staining, alkaline phosphatase (ALP) activity measurement, CCK-8 cell proliferation experiment, cytoskeleton phalloidin staining, qPCR and Western Blot were used to detect the effects of icariin on osteoblasts adhesion protein integrin α5 and integrin β1 and cytoskeleton protein F-actin under hypergravity extreme mechanical environment. Results All models were successfully prepared. The alizarin red staining: The icariin could significantly promote the formation of osteoblastic calcified nodules. And the 10 G loading could also promote the mineralization of osteoblasts and increase the number of mineralized nodules, while the mineralization and the number of mineralized nodules of osteoblasts are significantly reduced in 40 G loading. ALP activity test: The OD values of simple administration group, 10 G loading group and 40 G loading group were 0.246, 0.331 and 0.163, respectively. Compared with 0.207 in the control group, the differences were statistically significant (P<0.05). The 10 G administration group and the 40 G administration group were 0.373 and 0.180, and the differences were statistically significant (P<0.05). The results of CCK-8 proliferation experiments: The OD value of simple administration group were 0.650, which was statistically significant compared with 0.551 of control group (P=0.031). The 10 G loading group and 40 G loading group were 1.193 and 0.245, and their differences with the control group were both statistically significant (P<0.05). The OD value of 10G administration group and the 40 G administration group were 1.300 and 0.310, which were significantly different from the respective loading groups (P<0.05). Phalloidin staining: 10 G loading significantly increased the number of cells, but the changes in cells morphology and skeleton were not obvious. 40 G loading significantly inhibited the increase of the number of cells, meanwhile, made the pseudopods of cells more shorter and even disappeared. 40 G loading made the seriously damage of the cytoskeleton and even cause the cells to death. Icariin had no effect on the cells morphology, but it did has a certain repair effect after the cells loading. The results of qPCR and Western Blot experiments all confirmed that the expressions of integrin α5, integrin β1 and F-actin were up-regulated after icariin treatment. 10 G loading could promote the expression of integrin α5, integrin β1 and F-actin, and 40 G loading significantly inhibited the expression of the mRNA and proteins. Conclusion Both 10 G condition and icariin can promote the development, cell adhesion and the cytoskeleton's stability of osteoblasts, while 40 G has a significant inhibitory effect. Key words: Osteoblast; Hypergravity; Cell adhesion; Cytoskeleton

Convective boiling heat transfer under microgravity and hypergravity conditions

The present paper concerns an experimental investigation of the gravitational effects on subcooled and saturated flow boiling heat transfer in a vertical 3.75 mm diameter aluminum tube, using perfluorohexane as working fluid. Experimental results obtained during parabolic flights are compared with data gathered in the same test facility for normal gravity. Results were obtained for mass velocities of 133, 252, 377 and 428 kg/m2s, heat fluxes up to 106 kW/m2 and vapor qualities up to 0.28. The assessments of prediction methods from literature for flow boiling heat transfer proposed for normal gravitational conditions were evaluated through comparisons of calculated and experimental results. In general, for either a mass velocity of 428 kg/m2s or a vapor quality lower than -0.2, the gravitational effects on the heat transfer coefficient were found as negligible. For lower mass velocities and saturated flow boiling, higher heat transfer coefficients were observed under hypergravity conditions. This behavior was associated to the fact that higher gravitational forces favor bubbles detachment. The method of Kanizawa et al. [1] provided reasonable predictions of the saturated flow boiling results under microgravity and hyper gravity conditions, predicting 100% of the data within an error band of ±30%.

Stumbling reactions in hypo and hyper gravity \u2013 muscle synergies are robust across different perturbations of human stance during parabolic flights

The control of bipedal stance and the capacity to regain postural equilibrium after its deterioration in variable gravities are crucial prerequisites for manned space missions. With an emphasize on natural orthograde posture, computational techniques synthesize muscle activation patterns of high complexity to a simple synergy organization. We used nonnegative matrix factorization to identify muscle synergies during postural recovery responses in human and to examine the functional significance of such synergies for hyper-gravity (1.75 g) and hypo-gravity (0.25 g). Electromyographic data were recorded from leg, trunk and arm muscles of five human exposed to five modes of anterior and posterior support surface translations during parabolic flights including transitional g-levels of 0.25, 1 and 1.75 g. Results showed that in 1 g four synergies accounted for 99% of the automatic postural response across all muscles and perturbation directions. Each synergy in 1 g was correlated to the corresponding one in 0.25 and 1.75 g. This study therefore emphasizes the similarity of the synergy organization of postural recovery responses in Earth, hypo- and hyper-gravity conditions, indicating that the muscle synergies and segmental strategies acquired under terrestrial habits are robust and persistent across variable and acute changes in gravity levels.

Photothermal nanobubble nucleation on a plasmonic nanoparticle: A 3D lattice Boltzmann simulation

Nanobubble nucleation by plasmonic heating on a gold spherical nanoparticle under laser illumination is numerically investigated by a 3D liquid-vapor phase change lattice Boltzmann (LB) method. A volumetric heat source is incorporated to the evolution equation of temperature distribution function to simulate photothermal energy conversion effect in a plasmonic gold spherical nanoparticle induced by surface plasma resonance under laser illumination. A halfway bounce-back conjugate boundary condition on nanoparticle/liquid interface for LB simulation, with interfacial thermal resistance taken into consideration, is derived. It is confirmed that nanobubble nucleates on a laser heated hydrophilic gold spherical nanoparticle in a core-shell mode under normal gravity condition. To simulate nanobubble nucleation on a plasmonic nanoparticle in a spherical cap mode, an extraordinary (fictitious) hyper gravity environment would have to be imposed. Effects of nanoparticle surface’s wettability, nanoparticle-liquid interfacial thermal resistance, and nanoparticle’s diameter on nanobubble nucleation under normal gravity are investigated. The size of the nanoparticle is found to have non-monotonic effects on the threshold laser fluence of nanobubble nucleation, with the 60 nm gold nanoparticle having the lowest threshold laser fluence for nucleation. This finding is in agreement with existing experimental results.

Impact of g-Load Shift on Temporal Expression Pattern of Apoptosis-linked Proteins in the Rat Mammary Gland

Abstract Alteration in gravitational load impacts homeorhetic response in rat dams which affects neonatal pup survival. However, the effects of hypergravity (HG) exposure on the abundance of apoptosis-associated proteins in mammary epithelial cells (MECs) have not been characterized. Therefore, we examined whether chronic exposure to HG from midpregnancy alters the abundance of proapoptotic proteins in MECs during the late pregnancy and early lactation. A group of pregnant Sprague Dawley rats were exposed to either HG (2g) or normo-gravity (1g: stationary control [SC]) from days 11 to 20 of gestation (G20). Another set of animals were investigated from day 11 of pregnancy through days 1 and 3 (P1 and P3, respectively) postpartum. Quantitative (pixels [px]/lobule) immunohistochemistry at G20 of Cleaved Caspase-3 (CC-3), Tumor Protein p53 (P53), and vitamin D receptor (VDR) revealed that all the three proteins were increased (p&lt;0.01) in HG rats compared to SC animals. At P1, the HG group had twofold higher (p&lt;0.001) expression of CC-3 relative to the SC group. Approximately, 50% (p&lt;0.001) more VDR was detected in the HG cohorts than SC at P3. These results suggest that a shift in g-load upregulates the expression of key proapoptotic proteins during the pregnancy-to-lactation transition in the rat MECs.

Gravity-Independent Oscillate Boiling

Heat transfer in nucleate boiling relies on the detachment and rise of the boiling bubble, in which gravity plays the dominant role. Previous studies showed that in the absence of gravity, the bubble fails to rise, causing the dryout of the heater and significantly reducing the thermal efficiency of nucleate boiling. Recently, a new boiling regime termed oscillate boiling was discovered. By localizing thermal energy as high as 50 mW into an area as small as 15 × 15μm2, a boiling bubble is formed and oscillate at high frequency while remaining pinned at the heating spot. This regime was proposed to be independent of buoyancy as its operation does not involves the detachment and rise of the boiling bubble. To test this hypothesis, we compared experimental observations of oscillate boiling in low gravity, normal gravity and hyper gravity. The results support the hypothesis and promote its potential for outer-space heat transfer application.

Chronic Exposure to Altered Gravity During the Pregnancy-to-Lactation Transition Affects Abundance of Cytoskeletal Proteins in the Rat Mammary Gland

Abstract The mammogenic, lactogenic, and lactopoetic effects of prolactin (PRL) in the mammary gland are mediated through a specific cytokine receptor, the PRL-receptor (PRLR). PRLR is anchored to the cytoskeleton and its activation, and subsequent signal transduction, is dependent on an integral/intact cytoskeletal organization. Previous studies revealed a down-regulation of PRLR and reduced metabolic output in the mammary gland of rats exposed to hypergravity (HG). Therefore, the objective of this study was to use quantitative immunohistochemistry to determine the effects of HG exposure during pregnancy on the pre- and postpartum abundance of the cytoskeletal proteins in the rat mammary gland. Pregnant rats were exposed to either 2xg [HG] or 1xg [Stationary control (SC)] from days 11 to 20 of gestation (G20) through postpartum days 1 (P1) and 3 (P3). Spectral characterization and quantitation of each antigen (actin, tubulin, cytokeratin, and vimentin) per lobule (n=3–7 lobules/micrograph; 4 micrographs/slide) was computed using the CRi Nuance multispectral system. At G20 and P3, increased (p&lt;0.001) amounts of actin, tubulin, cytokeratin, and vimentin were detected in HG rats. Tubulin, cytokeratin, and vimentin were overexpressed (p&lt;0.01) in HG group compared to SC at P1. These results suggest that atypical composition of cytoskeletal proteins contribute to the aberrant lactogenic signal transduction and associated reduced postpartum mammary metabolic output in rats exposed to altered inertial environment.

Investigating Impacts of Hyper Gravity on Fully Imbibed Seed of Wheat and Analysis of Absorption Peaks of Chlorophyll A and B, Percentage of Germination, Weight of Fresh and Dry Shoot, Root, and Percentage of Chlorophyll

Investigating Impacts of Hyper Gravity on Fully Imbibed Seed of Wheat and Analysis of Absorption Peaks of Chlorophyll A and B, Percentage of Germination, Weight of Fresh and Dry Shoot, Root, and Percentage of Chlorophyll

Hippocampal gene expression, serum cortisol level, and spatial memory in rats exposed to hypergravity.

Due to spatial disorientation reported in space, spatial memory and navigation performances could be more largely impaired by gravity changes. Hippocampus, a key structure for spatial memory, receives inputs from gravity-sensing otolith organs. To determine the key molecules in the rat hippocampus that contribute to an adaptation to altered gravity in terms of spatial memory performance. Gene expression of hippocampus and spatial memory after continuous two-weeks exposure to 2 G hypergravity (HG) were examined using a microarray analysis followed by real-time PCR methods and radial arm maze testing, respectively. Serum cortisol levels during HG load were measured as a stress marker. Accuracy to enter the correct arms in HG rats was significantly lower than that of controls, indicating an impaired spatial memory due to gravity changes. Microarray analysis followed by real-time PCR confirmed an upregulation of insulin like growth factor binding protein 2 (IGFBP2) gene. Serum cortisol level was the same level as controls at the last day of hypergravity, suggesting the adaptation to HG-induced stress. Given that the IGF systems are involved in neurotrophic and synaptic plasticity mechanisms, IGF system might contribute to the adaptation to altered gravity in terms of spatial memory.

Hypergravity within a critical period impacts on the maturation of somatosensory cortical maps and their potential for use-dependent plasticity in the adult.

We investigated experience-dependent plasticity of somatosensory maps in rat S1 cortex during early development. We analyzed both short- and long-term effects of exposure to 2G hypergravity (HG) during the first 3 postnatal weeks on forepaw representations. We also examined the potential of adult somatosensory maps for experience-dependent plasticity after early HG rearing. At postnatal day 22, HG was found to induce an enlargement of cortical zones driven by nail displacements and a contraction of skin sectors of the forepaw map. In these remaining zones serving the skin, neurons displayed expanded glabrous skin receptive fields (RFs). HG also induced a bias in the directional sensitivity of neuronal responses to nail displacement. HG-induced map changes were still found after 16 wk of housing in normogravity (NG). However, the glabrous skin RFs recorded in HG rats decreased to values similar to that of NG rats, as early as the end of the first week of housing in NG. Moreover, the expansion of the glabrous skin area and decrease in RF size normally induced in adults by an enriched environment (EE) did not occur in the HG rats, even after 16 wk of EE housing in NG. Our findings reveal that early postnatal experience critically and durably shapes S1 forepaw maps and limits their potential to be modified by novel experience in adulthood.

Integrin αvβ3 mediates the synergetic regulation of core-binding factor α1 transcriptional activity by gravity and insulin-like growth factor-1 through phosphoinositide 3-kinase signaling

Mechanical stimulation and biological factors coordinately regulate bone development and regeneration; however, the underlying mechanisms are poorly understood. Microgravity induces bone loss, which may be partly related to the development of resistance to local cytokines, including insulin-like growth factor 1 (IGF-1). Here, we report the involvement of integrin αvβ3 in microgravity-associated bone loss. An established OSE-3T3 cell model was stably transfected with a 6OSE2 (Osteoblast-Specific Element 2)-luciferase reporter and cultured under simulated microgravity (SMG) and hypergravity (HG) conditions in the presence or absence of IGF-1, the disintegrin echistatin, the phosphoinositide 3-kinase (PI3K) inhibitor LY294002, or combinations of these agents. Activity of core-binding factor α1 (Cbfa1), an essential transcription factor for osteoblastic differentiation and osteogenesis, was reflected by luciferase activity. Different gravity conditions affected the induction of IGF-1 and subsequent effects on Cbfa1 transcription activity. SMG and HG influenced the expression and activity of integrin αvβ3 and phosphorylation level of p85. LY294002 inhibited the effects of HG or IGF-1 on Cbfa1 activity, indicating that HG and IGF-1 could increase Cbfa1 activity via PI3K signaling. Inhibition of integrin αvβ3 by echistatin attenuated the induction of IGF-1 and thus its effect on Cbfa1 activity under normal and HG conditions. Co-immunoprecipitation demonstrated that integrin β3 interacted with insulin receptor substrate 1, and that this interaction was decreased under SMG and increased under HG conditions. These results suggest that integrin αvβ3 mediates the synergetic regulation of Cbfa1 transcription activity by gravity and IGF-1 via PI3K signaling.

Effects of hypergravity exposure after 30-days simulated weightlessness on chemokine CCL20 and its receptor CCR6 in lingual mucosa of rhesus macaque

To study the influence of hypergravity exposure after 30-days simulated weightlessness on the expression of chemokine CCL20 and its receptor CCR6 in lingual mucosa of rhesus macaque. Twenty-three male rhesus monkeys were divided according to the random number method into one control group (A, n = 3) and three experimental groups, including the weightlessness group (B, n = 3), the hypergravity group (C, n = 3) and hypergravity exposure after 30-days simulated weightlessness group (D, n = 14), which was further divided into four subgroups according to the values of overload as: +11 Gx/270s group (D1, n = 3), +13 Gx/230s group (D2, n = 4) and +15 Gx/200s group (D3, n = 4) and +13 Gx/230s with 9-days recovery group (D4, n = 3). Histopathological changes of lingual mucosa were observed by hematoxylin-eosin staining and the expressions of CCL20 and CCR6 were detected by immunohistochemistry (IHC) and quantitative real-time PCR (Q-PCR). Histological observation showed that no significant histopathological changes were found in the lingual mucosa in all experimental groups of the animals, however, there were more infiltrated lymphocyte and neutrophils in the experimental groups. The immunohistochemical scores of CCL20 in group C, group D2 and group D3 were 1.30 ± 0.11, 1.68 ± 0.62 and 2.26 ± 1.00, respectively, significantly higher than that in A group (0.47 ± 0.12, P < 0.05). The immunohistochemical scores of CCR6 expression in those three groups were 4.40 ± 1.48, 6.67 ± 2.04 and 7.02 ± 2.11, respectively, also remarkably higher than that in A group (1.33 ± 0.66, P < 0.05). As far as the mRNA expression was concerned, the expressions of CCL20 and CCR6 had similar change trend with their protein expressions. Hypergravity exposure after 30-days simulated weightlessness will not lead to significant pathological changes in lingual mucosa, but can induce the expression of chemokine CCL20 and its receptor CCR6.

Exposure to hypergravity increases serum interleukin-5 and pulmonary infiltration in mice with allergic asthma.

ObjectiveWe evaluated the effect of acute hypergravity (HG) on the immune response in a murine model of allergic asthma.Material and methodsTwenty-eight BALB/c mice were used. Group A (control group, n = 7) mice were sensitized and challenged with normal saline. Group B (control HG exposure group, n = 7) mice were sensitized, challenged with saline, and exposed to acute HG (+10 Gz) for 4 hours. Group C (asthma group, n = 7) mice were challenged with intraperitoneal and intranasal ovalbumin (OVA) to induce asthma. Group D (asthma HG exposure group, n = 7) mice were exposed to HG for 4 hours after the induction of asthma. We estimated the total and OVA-specific serum IgE, serum titers of various cytokines, and the number of eosinophils, neutrophils, and lymphocytes in bronchoalveolar lavage (BAL) fluid. Histopathology of the lung was also evaluated.ResultsThe serum level of interleukin (IL)-5 was significantly higher in Group D (12.9 ±4.9 pg/ml) compared to that in Group C (4.7 ±6.5 pg/ml, p = 0.017). In BAL fluid, the number of neutrophils was significantly increased in Group D compared to Group C (p = 0.014). Group D demonstrated a higher infiltration of inflammatory cells (9973.8 ±1642.7 cells/mm2) compared to Group C (7666.3 ±586.5 cells/mm2, p = 0.017). This tendency of increase in infiltration was not significant in non-asthmatic animals (Group A: 4488.8 ±176.1 cells/mm2 vs. Group B: 4946.3 ±513.7 cells/mm2, p > 0.05).ConclusionsAcute HG exacerbated the allergic response by increasing serum IL-5 levels and promoting pulmonary infiltration of inflammatory cells.

Hypergravity induces overexpression of inducible nitric oxide synthase in mouse livers

Hypergravity induces overexpression of inducible nitric oxide synthase in mouse livers