Search

Sigma-2 receptor plays key roles in promoting tumor cell apoptosis, enhancing efficacy of anti-tumor drugs, blocking signal transduction controlled by Aβ oligomers, regulating Ca2+ homeostasis and protecting nerve cells. Studies indicated that sigma-2 receptor may be closely coupled with ROS, LDL, mTOR, RAS, PLC/PKC, lysosomal autophagy and mitochondrial super oxidative stress. In addition, the high expression of this receptor in proliferating cells and nerve cells indicates that sigma-2 receptor is an ideal molecular target for imaging and therapeutic development for cancer, Alzheimer's disease, schizophrenia and traumatic brain injury. Various sigma-2 agonists have shown promising anticancer activities, while sigma-2 antagonists have displayed neuroprotection and inhibition of Aβ oligomers in the brain of Alzheimer's disease patients. Thus, both sigma-2 agonists and antagonists are potentially useful therapeutics for the management of cancer and neurodegenerative disorders.

The synergetic effects between cavitation bubbles and silt particles on the damages of materials are essential problems in fluid machineries. For studying the underlying microscopic mechanisms, in the present paper, the dynamic behaviors of a single cavitation bubble between a spherical particle and a rigid wall are experimentally investigated with a high-speed camera. The results indicate that the existence of the particle can affect the bubble shape during collapse and significantly accelerate the collapse velocity of the bubble. The influences of the particle size, the distance between the bubble and the particle and the distance between the bubble and the rigid wall on the phenomena are qualitatively and quantitatively analyzed. These parameters can prominently affect the collapse velocity of the bubble (especially its maximum value).

Cylinder compression pressure reflects the air tightness of engine. A method for measuring the compression pressure of cylinder indirectly through measuring the vibration signal of cylinder head was studied and then to detect the air tightness. The air pressure signal in cylinder and vibration signals of cylinder head were measured at the same time when the diesel engine was driven by the motor. According to port timing, the vibration signal excited by cylinder pressure was separated using time domain analysis. A RBF neural network model was set up to build the relation between compression pressure and cylinder head vibration. So the air tightness of cylinder can be detected after calculating the compression pressure by use of neural network.