scholarly journals Morphofunctional, viability and antioxidant system alterations on rat primary testicular cells exposed to simulated microgravity

Author(s):  
Valentina Bonetto ◽  
Linda Scarabelli ◽  
Maria Angela Masini

This study focused on effects induced by short-term simulated microgravity (SMG) condition on primary cell culture from pre-pubertal Wistar rats testis. Cells were analyzed for cytoskeletal and Sex Hormone Binding Globulin (SHBG/ABP) changes by immunofluorescence technique, for antioxidant system exploiting RT-PCR and cell viability. Cells were cultured for 6 and 24h on a three-dimensional clinostat, Random Positioning Machine (RPM). At the end of each experiment, once stopped the RPM rotation, cells were either fixed in paraformaldehyde or lysed and RNA extracted. In cells exposed to SMG the cytoskeleton became disorganized, microtubules fragmented and SHBG was already undetectable after 6h of treatment. Moreover, various antioxidant systems significantly increased after 24h of SMG exposure. Initially, SMG seemed to disturb antioxidant protection strategies allowing the testes to support sperm production, thus generating an aging-like state of oxidative stress. Studies on changes induced by short-term altered gravity conditions, carried out in real microgravity, could give more information on steroidogenesis and germ cell differentiation within the testis exposed to this condition and confirm the validity of simulation approach.

1994 ◽  
Vol 29 (2-3) ◽  
pp. 293-308
Author(s):  
J. Koponen ◽  
M. Virtanen ◽  
H. Vepsä ◽  
E. Alasaarela

Abstract Three-dimensional (3-D) mathematical models of water currents, transport, mixing, reaction kinetic, and interactions with bottom and air have been used in Finland regularly since 1982 and applied to about 40 cases in large lakes, inland seas and their coastal waters. In each case, model validity has been carefully tested with available flow velocity measurements, tracer studies and water quality observations. For operational use, i.e., for spill combatting and sea rescue, the models need fast response, proven validity and illustrative visualization. In 1987-90, validated models were implemented for operational use at five sea areas along the Finnish coast. Further validation was obtained in model applications from nine documented or arranged cases and from seven emergency situations. Sensitivity tests supplement short-term validation. In the Bothnian Sea, it was nescessary to start the calculation of water currents three days prior to the start of the experiment to reduce initial inaccuracies and to make the coastal transport estimates meaningful.


2021 ◽  
Vol 13 (9) ◽  
pp. 4905
Author(s):  
Chen Cao ◽  
Xiangbin Wu ◽  
Lizhi Yang ◽  
Qian Zhang ◽  
Xianying Wang ◽  
...  

Exploring the spatiotemporal distribution of earthquake activity, especially earthquake migration of fault systems, can greatly to understand the basic mechanics of earthquakes and the assessment of earthquake risk. By establishing a three-dimensional strike-slip fault model, to derive the stress response and fault slip along the fault under regional stress conditions. Our study helps to create a long-term, complete earthquake catalog. We modelled Long-Short Term Memory (LSTM) networks for pattern recognition of the synthetical earthquake catalog. The performance of the models was compared using the mean-square error (MSE). Our results showed clearly the application of LSTM showed a meaningful result of 0.08% in the MSE values. Our best model can predict the time and magnitude of the earthquakes with a magnitude greater than Mw = 6.5 with a similar clustering period. These results showed conclusively that applying LSTM in a spatiotemporal series prediction provides a potential application in the study of earthquake mechanics and forecasting of major earthquake events.


Heart ◽  
2001 ◽  
Vol 85 (5) ◽  
pp. 514-520
Author(s):  
W Y Kim ◽  
P Søgaard ◽  
P T Mortensen ◽  
H Kjærulf Jensen ◽  
A Kirstein Pedersen ◽  
...  

OBJECTIVESTo quantify the short term haemodynamic effects of biventricular pacing in patients with heart failure and left bundle branch block by using three dimensional echocardiography.DESIGNThree dimensional echocardiography was performed in 15 consecutive heart failure patients (New York Heart Association functional class III or IV) with an implanted biventricular pacing system. Six minute walk tests were performed to investigate the effect of biventricular pacing on exercise capacity. Data were acquired at sinus rhythm and after short term (2–7 days) biventricular pacing.RESULTSCompared with baseline values, biventricular pacing significantly reduced left ventricular end diastolic volume (EDV) by mean (SD) 4.0 (5.1)% (p < 0.01) and end systolic volume (ESV) by 5.6 (6.4)% (p < 0.02). Mitral regurgitant fraction was significantly reduced by 11 (12.1)% (p < 0.003) and forward stroke volume (FSV) increased by 13.9 (18.6)% (p < 0.02). Exercise capacity was significantly improved with biventricular pacing by 48.4 (43.3)% (p < 0.00001). Regression analyses showed that the percentage increase in FSV independently predicted percentage improvement in walking distance (r2 = 0.73, p < 0.0002). Both basal QRS duration and QRS narrowing predicted pacing efficacy, showing a significant correlation with %ΔEDV, %ΔESV, and %ΔFSV.CONCLUSIONSIn five of 15 consecutive patients with heart failure and left bundle branch block, biventricular pacing induced a more than 15% increase in FSV, which predicted a more than 25% increase in walking distance and was accompanied by an immediate reduction in left ventricular chamber size and mitral regurgitation.


2017 ◽  
Vol 14 (1) ◽  
pp. 172988141769231 ◽  
Author(s):  
Ning An ◽  
Shi-Ying Sun ◽  
Xiao-Guang Zhao ◽  
Zeng-Guang Hou

Visual tracking is a challenging computer vision task due to the significant observation changes of the target. By contrast, the tracking task is relatively easy for humans. In this article, we propose a tracker inspired by the cognitive psychological memory mechanism, which decomposes the tracking task into sensory memory register, short-term memory tracker, and long-term memory tracker like humans. The sensory memory register captures information with three-dimensional perception; the short-term memory tracker builds the highly plastic observation model via memory rehearsal; the long-term memory tracker builds the highly stable observation model via memory encoding and retrieval. With the cooperative models, the tracker can easily handle various tracking scenarios. In addition, an appearance-shape learning method is proposed to update the two-dimensional appearance model and three-dimensional shape model appropriately. Extensive experimental results on a large-scale benchmark data set demonstrate that the proposed method outperforms the state-of-the-art two-dimensional and three-dimensional trackers in terms of efficiency, accuracy, and robustness.


2014 ◽  
Vol 13 (3) ◽  
pp. 51-55
Author(s):  
L. G. Netyukhailo ◽  
T. A. Sukhomlin ◽  
Ya. A. Basarab ◽  
V. V. Bondarenko ◽  
S. V. Kharchenko

The objective of research was to study the state of prooxidant and antioxidant systems in the tissues of the lungs, kidneys, pancreas and salivary glands at burn disease. The intensity of the free radical processes was evaluated on the basis of the content of malondialdehyde (MDA) and antioxidant system – based on the indexes of its enzymatic chain: superoxide dismutase and catalase in homogenates of the studied organs. It has been found that changes in experimental burn disease depend on the studied organs and the stage of burn disease. The activation of free radical processes observed in all investigated organs (lungs, kidneys, pancreas and salivary glands). Reactive oxygen species induce lipid peroxidation, which is a universal marker of tissue damage. MDA appears in the body during degradation of polyunsaturated fatty acids and it’s a marker of lipid peroxidation and oxidative stress. It was found the increasing of MDA in all organs, especially in the lungs and kidneys at stage of burn shock. Under these conditions it was observed the decrease of superoxide dismutase and catalase in all investigated organs. At burn disease there is development of disbalance between the action of prooxidant and antioxidant systems due to the activation of free radical processes.


2021 ◽  
Vol 13 (18) ◽  
pp. 3584
Author(s):  
Peng Liu ◽  
Yi Yang ◽  
Yu Xin ◽  
Chenghai Wang

A moderate precipitation event occurring in northern Xinjiang, a region with a continental climate with little rainfall, and in leeward slope areas influenced by topography is important but rarely studied. In this study, the performance of lightning data assimilation is evaluated in the short-term forecasting of a moderate precipitation event along the western margin of the Junggar Basin and eastern Jayer Mountain. Pseudo-water vapor observations driven by lightning data are assimilated in both single and cycling analysis experiments of the Weather Research and Forecast (WRF) three-dimensional variational (3DVAR) system. Lightning data assimilation yields a larger increment in the relative humidity in the analysis field at the observed lightning locations, and the largest increment is obtained in the cycling analysis experiment. Due to the increase in water vapor content in the analysis field, more suitable thermal and dynamic conditions for moderate precipitation are obtained on the leeward slope, and the ice-phase and raindrop particle contents increase in the forecast field. Lightning data assimilation significantly improves the short-term leeward slope moderate precipitation prediction along the western margin of the Junggar Basin and provides the best forecast skill in cycling analysis experiments.


Author(s):  
N. V. Marmiy ◽  
D. S. Esipov

The changes of the 8-oxo-2'-deoxyguanosine (8-oxo-dG)/dG ratio in the DNA of laboratory mice hepatocytes under the influence of toxic stress were studied. It was shown that the injection of carbon tetrachloride causes the growth of 8-oxo-dG level. A rapid increase in the level of 8-oxo-dG in DNA occurs during the first day of the experiment at short-term toxic stress. Subsequently, 48 hours after the initial injection, the level of 8-oxo-dG decreases to the control values. This change in the value of the biomarker can be attributed to the activation of the reparative and antioxidant systems. The subsequent injection results again in an increase of 8-oxo-dG level, and the latter only increases thereafter. This reflects the exhaustion of the reparative potential of the organism and accompanies the progress of inflammation and pathological change of the liver tissue.


2017 ◽  
Vol 13 (S335) ◽  
pp. 243-249 ◽  
Author(s):  
Huaning Wang ◽  
Yihua Yan ◽  
Han He ◽  
Xin Huang ◽  
Xinghua Dai ◽  
...  

AbstractIt is well known that the energy for solar eruptions comes from magnetic fields in solar active regions. Magnetic energy storage and dissipation are regarded as important physical processes in the solar corona. With incomplete theoretical modeling for eruptions in the solar atmosphere, activity forecasting is mainly supported with statistical models. Solar observations with high temporal and spatial resolution continuously from space well describe the evolution of activities in the solar atmosphere, and combined with three dimensional reconstruction of solar magnetic fields, makes numerical short-term (within hours to days) solar activity forecasting possible. In the current report, we propose the erupting frequency and main attack direction of solar eruptions as new forecasts and present the prospects for numerical short-term solar activity forecasting based on the magnetic topological framework in solar active regions.


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