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Mitochondria play a central role in energy metabolism and cell survival. They often undergo structural and dynamic changes under various types of stress and impaired energy homeostasis. In addition to the intracellular movement of mitochondria, their intercellular transport is of great importance. Intercellular transfer occurs in both physiological conditions and various pathologies. It is accompanied by elimination of damage in stressed cells and the restoration of structural and functional tissue disorders caused by mitochondrial dysfunction. This review summarizes the latest data accumulated in this area and provides a general idea on the molecular mechanisms of mitochondrial intercellular transport and its role in maintaining energy homeostasis in tissues. Promising ways of studying mitochondrial transfer for targeted therapy of many diseases are discussed separately. [ABSTRACT FROM AUTHOR]

This paper is concerned with the nonzero mean stationary probability density function (PDF) solution for nonlinear oscillators under external Gaussian white noise. The PDF solution is governed by the well-known Fokker-Planck-Kolmogorov (FPK) equation and this equation is numerically solved by the exponential-polynomial closure (EPC) method. Different types of oscillators are further investigated in the case of nonzero mean response. Either weak or strong nonlinearity is considered to show the effectiveness of the EPC method. When the polynomial order equals 2, the results of the EPC method are identical with those given by equivalent linearization (EQL) method. These results obtained with the EQL method differ significantly from exact solution or simulated results. When the polynomial order is 4 or 6, the PDFs obtained with the EPC method present a good agreement with the exact solution or simulated results, especially in the tail regions. The numerical analysis also shows that the nonzero mean PDF of the response is nonsymmetrically distributed about its mean unlike the case of the zero mean PDF reported in the references. [ABSTRACT FROM AUTHOR]

Abstract  The approximate nonstationary probability density of a nonlinear single-degree-of-freedom (SDOF) oscillator with time delay subject to Gaussian white noises is studied. First, the time-delayed terms are approximated by those without time delay and the original system can be rewritten as a nonlinear stochastic system without time delay. Then, the stochastic averaging method based on generalized harmonic functions is used to obtain the averaged Itô equation for amplitude of the system response and the associated Fokker–Planck–Kolmogorov (FPK) equation governing the nonstationary probability density of amplitude is deduced. Finally, the approximate solution of the nonstationary probability density of amplitude is obtained by applying the Galerkin method. The approximate solution is expressed as a series expansion in terms of a set of properly selected basis functions with time-dependent coefficients. The proposed method is applied to predict the responses of a Van der Pol oscillator and a Duffing oscillator with time delay subject to Gaussian white noise. It is shown that the results obtained by the proposed procedure agree well with those obtained from Monte Carlo simulation of the original systems. [ABSTRACT FROM AUTHOR]

Changes of groundwater level, ranging from a fall of 11.10 m to a rise of 7.42 m, induced by thrust faulting during the 1999 Mw 7.6, Chi-Chi earthquake have been recorded in 276 monitoring wells in Taiwan. Most coseismic falls appeared near the seismogenic fault as well as other active faults, while coseismic rises prevailed away from the fault. Coseismic groundwater level rises and falls correlated fairly well with hypocentral distance in the vicinity of the thrust fault. We found a major difference of coseismic changes in wells of different depths at most multiple-well stations. The recovery process of coseismic groundwater level changes is associated with the confining condition of the aquifer. Cross-formational flow is likely to play an important role in groundwater level changes after the earthquake. In the hanging wall of the thrust fault, an abnormal decline of groundwater level was observed immediately before the earthquake. The underlying mechanism of the unique preseismic change warrants further investigation. [ABSTRACT FROM AUTHOR]

Study on the action mechanism of inflammatory mediators generated by the severe acute pancreatitis (SAP) in multiple organ injury is a hotspot in the surgical field. In clinical practice, the main complicated organ dysfunctions are shock, respiratory failure, renal failure, encephalopathy, with the rate of hepatic diseases being closely next to them. The hepatic injury caused by SAP cannot only aggravate the state of pancreatitis, but also develop into hepatic failure and cause patient death. Its complicated pathogenic mechanism is an obstacle in clinical treatment. Among many pathogenic factors, the changes of vasoactive substances, participation of inflammatory mediators as well as OFR (oxygen free radical), endotoxin, etc. may play important roles in its progression. [ABSTRACT FROM AUTHOR]