Study of Histopathological and Molecular Changes of Rat Kidney under Simulated Weightlessness and Resistance Training Protective Effect

To explore the effects of long-term weightlessness on the renal tissue, we used the two months tail suspension model to simulate microgravity and investigated the simulated microgravity on the renal morphological damages and related molecular mechanisms. The microscopic examination of tissue structure and ultrastructure was carried out for histopathological changes of renal tissue morphology. The immunohistochemistry, real-time PCR and Western blot were performed to explore the molecular mechanisms associated the observations. Hematoxylin and eosin (HE) staining showed severe pathological kidney lesions including glomerular atrophy, degeneration and necrosis of renal tubular epithelial cells in two months tail-suspended rats. Ultrastructural studies of the renal tubular epithelial cells demonstrated that basal laminas of renal tubules were rough and incrassate with mitochondria swelling and vacuolation. Cell apoptosis in kidney monitored by the expression of Bax/Bcl-2 and caspase-3 accompanied these pathological damages caused by long-term microgravity. Analysis of the HSP70 protein expression illustrated that overexpression of HSP70 might play a crucial role in inducing those pathological damages. Glucose regulated protein 78 (GRP78), one of the endoplasmic reticulum (ER) chaperones, was up-regulated significantly in the kidney of tail suspension rat, which implied that ER-stress was associated with apoptosis. Furthermore, CHOP and caspase-12 pathways were activated in ER-stress induced apoptosis. Resistance training not only reduced kidney cell apoptosis and expression of HSP70 protein, it also can attenuate the kidney impairment imposed by weightlessness. The appropriate optimization might be needed for the long term application for space exploration

Fermion-boson many-body interplay in a frustrated kagome paramagnet

Kagome-net, appearing in areas of fundamental physics, materials, photonic and cold-atom systems, hosts frustrated fermionic and bosonic excitations. However, it is extremely rare to find a system to study both fermionic and bosonic modes to gain insights into their many-body interplay. Here we use state-of-the-art scanning tunneling microscopy and spectroscopy to discover unusual electronic coupling to flat-band phonons in a layered kagome paramagnet. Our results reveal the kagome structure with unprecedented atomic resolution and observe the striking bosonic mode interacting with dispersive kagome electrons near the Fermi surface. At this mode energy, the fermionic quasi-particle dispersion exhibits a pronounced renormalization, signaling a giant coupling to bosons. Through a combination of self-energy analysis, first-principles calculation, and a lattice vibration model, we present evidence that this mode arises from the geometrically frustrated phonon flat-band, which is the lattice analog of kagome electron flat-band. Our findings provide the first example of kagome bosonic mode (flat-band phonon) in electronic excitations and its strong interaction with fermionic degrees of freedom in kagome-net materials.Comment: To appear in Nature Communications (2020

MiR-124 Promote Neurogenic Transdifferentiation of Adipose Derived Mesenchymal Stromal Cells Partly through RhoA/ROCK1, but Not ROCK2 Signaling Pathway.

OBJECTIVE:Some recent studies suggest that multiple miRNAs might regulate neurogenic transdifferentiation of mesenchymal stromal cells (MSCs). In the present study, we hypothesized that the miR-124 can repress the expression of RhoA upon the neurogenesis of adipose derived MSCs (ADMSCs). METHODS:MiRNA expression dynamics during neurogenic transdifferentiation of ADMSCs were measured. The expression of neuron-specific enolase (NSE), Tuj-1 (Neuron-specific class III beta-tubulin) and glial fibrillary acidic protein (GFAP), as well as electrophysiological properties, were detected after neurogenic transdifferentiation. The targeting of miR-124 over RhoA was verified by dual luciferase assay, qRT-PCR and western blot. The functions of miR-124 and the RhoA/ROCK signaling pathway were studied using gain and loss of function experiments in vitro. RESULTS:MiR-124 is significantly upregulated during neurogenic transdifferentiation of ADMSCs. Knockdown of endogenous miR-124 hampered neurogenic transdifferentiation and the acquired electrophysiological properties. MiR-124 could directly target RHOA mRNA and repress its expression, through which it increased the proportion of transdifferentiated (transdiff.) cells with positive NSE, Tuj-1 and GFAP. RhoA/ROCK1, but not ROCK2 is a downstream signaling pathway of miR-124 in the process of transdifferentiation. CONCLUSION:MiR-124 is an important miRNA modulating neurogenic transdifferentiation of ADMSCs at least partly via the miR-124/RhoA/ROCK1 signaling pathway. These findings provided some fundamental information for future use of ADMSCs as an agent for regenerative medicine and cell therapy for neurological diseases

Urbanization, economic development and health: evidence from China’s labor-force dynamic survey

Abstract Background The frequent outbreak of environmental threats in China has resulted in increased criticism regarding the health effects of China’s urbanization. Urbanization is a double-edged sword with regard to health in China. Although great efforts have been made to investigate the mechanisms through which urbanization influences health, the effect of both economic development and urbanization on health in China is still unclear, and how urbanization-health (or development-health) relationships vary among different income groups remain poorly understood. To bridge these gaps, the present study investigates the impact of both urbanization and economic development on individuals’ self-rated health and its underlying mechanisms in China. Methods We use data from the national scale of the 2014 China Labor-force Dynamics Survey to analyze the impact of China’s urbanization and economic development on health. A total of 14,791 individuals were sampled from 401 neighborhoods within 124 prefecture-level cities. Multilevel ordered logistic models were applied. Results Model results showed an inverted U-shaped relationship between individuals’ self-rated health and urbanization rates (with a turning point of urbanization rate at 42.0%) and a positive linear relationship between their self-rated health and economic development. Model results also suggested that the urbanization-health relationship was inverted U-shaped for high- and middle-income people (with a turning point of urbanization rate at 0.0% and 49.2%, respectively), and the development-health relationship was inverted U-shaped for high- and low-income people (with turning points of GDP per capita at 93,462 yuan and 71,333 yuan, respectively) and linear for middle-income people. Conclusion The impact of urbanization and economic development on health in China is complicated. Careful assessments are needed to understand the health impact of China’s rapid urbanization. Social and environmental problems arising from rapid urbanization and economic growth should be addressed. Equitable provision of health services are needed to improve low-income groups’ health in highly urbanized cities

The Dynamic Characteristic Analysis of the Water Lubricated Bearing-Rotor System in Seawater Desalination Pump

In order to study the water lubricated bearing-rotor system in seawater desalination pump, this paper is based on the coupling between the lubricating flow field and the rotor dynamics. The fluid-solid interaction (FSI) method, Rigid Body, was adopted to study the journal orbit of the bearing-rotor system under the periodic unbalancing load. The influences of geometric and working parameter to the journal orbit were combined to analyze the stability and reliability of the bearing-rotor system. The result shows that increasing the rotating speed would increase the journal whirling amplitude and the system sensitivity to the external excitation and unbalancing load were promoted; increasing the aspect ratio would reduce the journal whirling amplitude and cause the system to be more unstable; increasing the inlet pressure would reduce the journal whirling amplitude and cause the system to be more unstable; increasing the unbalancing load would reduce the stability margin and the system is easy to be unstable if obstructed; increasing the radial clearance would reduce the journal whirling amplitude and cause the system to be more unstable. The attitude angle has no influence on the journal whirling amplitude but would influence the stability of system and the value of attitude angle should not be large

The Relationship between Air Pollution and Depression in China: Is Neighbourhood Social Capital Protective?

There is increasing evidence from the developed world that air pollution is significantly related to residents’ depressive symptoms; however, the existence of such a relationship in developing countries such as China is still unclear. Furthermore, although neighbourhood social capital is beneficial for health, whether it is a protective factor in the relationship between health and environment pollution remains unclear. Consequently, we examined the effects of cities’ PM2.5 concentrations on residents’ depressive symptoms and the moderating effects of neighbourhood social capital, using data from the 2016 wave of China Labourforce Dynamics Survey and the real-time remote inquiry website of Airborne Fine Particulate Matter and Air Quality Index. Results showed that PM2.5 concentrations and neighbourhood social capital may increase and decrease respondents’ depressive symptoms, respectively. Notably, neighbourhood social capital decreased the negative effect of PM2.5 concentrations on respondents’ depressive symptoms. These analyses contributed to the understanding of the effect of air pollution on mental health in China and confirmed that neighbourhood social capital were protective factors in the relationship between health and environment hazards

Exploring the links between population density, lifestyle, and being overweight: secondary data analyses of middle-aged and older Chinese adults

BackgroundThe increasing prevalence of obesity across all age groups has become a major health concern in China. Previous studies have found strong links between population density, sedentary lifestyle, and the risk of being overweight among adults and adolescents in Western countries. However, little research has been conducted to disentangle this relationship in China, which is rapidly urbanizing and densely populated. Compared to other age groups, middle-aged and older adults tend to have a higher risk of being overweight, which increases their risk of diabetes, high blood pressure, and other weight-related chronic diseases. In addition, they are especially sensitive to neighbourhood environmental factors such as population density. Therefore, we aimed to unravel the link between population density and the risk of being overweight among Chinese middle-aged and older adults, with a particular focus on the mediating role of lifestyle choices.MethodsData from the 2011 China Health and Retirement Longitudinal Study were analysed. Individuals (N = 5285) were sampled from 405 neighbourhoods nested within 150 cities. Body Mass Index (BMI) was calculated based on self-reported body weight and height (being overweight was defined as a BMI ≥ 24 kg/m2). Multilevel regression and mediation analyses were applied to explore associations between population density, a sedentary lifestyle, and the risk of being overweight.ResultsMiddle-aged and older adults who lived in densely populated neighbourhoods had higher odds of being overweight. Further, this link was mediated by residents’ mode of travel and physical exercise; specifically, these residents had higher odds of owning a car and spending lesser time on weekly physical exercise, thereby increasing their risk of being overweight. Furthermore, the association between car ownership and the odds of being overweight varied by neighbourhood population density.ConclusionsThere was a positive association between neighbourhood population density and middle-aged and older adults’ risk of being overweight. This relationship may exist because people who live in densely populated neighbourhoods tend to lead a sedentary lifestyle. Our findings also suggest that, in rapidly urbanizing countries, a sedentary lifestyle may be especially harmful to middle-aged and older adults who live in densely populated neighbourhoods

MiR-124 knockdown hampers the acquired electrophysiological properties due to transdifferentiation.

<p>(A) Representative traces of intracellular calcium dynamics (ratiometric acquisition) showing lack of response of untransdifferentiated ADMSCs at biochemical depolarization with 50 nM KCI while still preserving their functional response following exposure to 1 mM ATP. (B) Representative traces of intracellular calcium dynamics (ratiometric acquisition) showing functional response of transdiff. ADMSCs (without miR-124 knockdown: up; with miR-124 knockdown: down) both at biochemical depolarization with KCI as well as the electrical field potential stimulation. However, the responses of the transdiff. ADMSCs/miR-124(-) were significantly weaker. (C) Representative traces of intracellular calcium dynamics (ratiometric acquisition) of mature hippocampal neurons (HN) at biochemical depolarization with 50 nM KCI. (D) Quantification of the peak of intensity of response of transdiff. ADMSC and neurons following exposure to 50 mM KCI (Δ340/380; ADMSCs naive = 0.002±0.001, n = 6; transdiff. ADMSCs = 0.052±0.006, n = 6; transdiff. ADMSCs/miR-124(-) = 0.023±0.008, n = 6; HN = 0.133±0.021, n = 6). (E) Quantitative evaluation of membrane potential values in ADMSCs, transdiff. ADMSCs (with or without miR-124 knockdown) and in hippocampal neurons (ADMSCs naive: 10.13±4.22 mV, n = 6; transdiff. ADMSCs = -42.52±5.31 mV, n = 6; transdiff. ADMSCs/miR-124(-) = -16.37±4.42 mV, n = 6; HN = -52.75±7.48, n = 6). *: comparison with ADMSCs; #: comparison with transdiff. ADMSCs. * and # <i>p</i><0.05, ** and ## <i>p</i><0.01, *** and ### <i>p</i><0.001.</p