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This research experimentally investigated effects of injection pressure, formation chamber and bypass flow on spray performances and cryogenic characteristics of CO2 snow under cryosurgery guided by endoscopic. Results show that CO2 snow has a superior freezing capability in the application of cryosurgery. The length of formation chamber is an effective design parameter to control spray performances and cryogenic characteristics. Increase in the length of formation chamber can increase snow size and conversion ratio, as well as the cooling rate and impact area of the tissue. Thus, it is suitable for the application on wider range nidus. Moreover, the bypass flow can efficiently modulate the cooling effect of the main flow with CO2 snow particles, and extend the operation time of cryosurgery. The experimental results also show that decrease the cylinder pressure, decrease the length of formation chamber, and increase the diameter of bypass apertures can slow down the flying velocity of CO2 snow which are effective methods to control the jet velocity and prevent the risk of penetration.

Intracerebral hemorrhage (ICH) is a devastating subtype of stroke that is characterized by significant morbidity and mortality. Thus far, there is no effective treatment option for spontaneous ICH. In this study, we aimed to investigate the effects of local hypothermia on brain injuries after ICH.Bacterial collagenase was used to induce ICH stroke in male Wistar rats. We assessed the effects of normothermia and 4 hours of local hypothermia (~33.2°C) initiated 1 hour after collagenase infusion on the neurological outcomes and brain water content at 1 and 3 days after ICH. The pathological changes of neuronal ultrastructure were examined with transmission electron microscopy. Furthermore, the expression levels of apoptotic molecules and matrix metalloproteinases-9 (MMP-9) were determined using western blotting and immunohistochemical staining. Results :Local hypothermia tends to reduce neurological deficits compared with the normothermic group at day 3 after ICH. Transmission electron microscopy reveals that local hypothermia significantly improves the ultrastructural outcomes at 1 and 3 days after ICH. In addition, local hypothermia markedly reduces edema formation and the expression levels of MMP-9 and apoptotic signal.These data suggest that local hypothermia induces a reduction in the brain edema and partly reduces neurological deficits along with marked inhibitory effects on MMP-9 and cell apoptosis after ICH.

A non-invasive dual-functional eye measurement system is developed by integrating spectral domain optical coherence tomography (SD-OCT) system with an optical reflectometer. The integrated system measures anterior segment of the eye as commonly performed by a SD-OCT while at the same time provides high resolution evaluation of tear film thickness and tear thinning dynamics. 6 μm axial resolution for anterior segment imaging and high resolution of 21nm for tear film thickness measurement are achieved. The present minimum measured tear film thickness is 0.3 μm. As a phantom study, a model eye with artificial tear film is evaluated using the integrated OCT/reflectometer device.

High precision speed and position tracking control is important to ensure safe and reliable operation of high speed train. This paper presents a solution to achieve fault-tolerant control of train consisting of multiple vehicles with distributed traction and braking systems. A multiple point-mass model coupled with uncertain resistive forces (i.e. aerodynamic resistance, mechanical resistance, transient impacts, etc.) is utilized for control design and stability analysis. Traction and braking faults in the form of tracking power loss and/or braking capability loss are explicitly considered. To cope with the resultant dynamic model that contains actuator faults, uncertain in-train forces as well as resistive disturbances, a fuzzy-adaptive fault-tolerant control method is proposed. The salient feature of the developed control scheme lies in its independence of the precise dynamic model of the train. More specifically, there is no need for system parameter estimation, no need for fault detection and diagnosis, and no need for in-train force and resistive force estimation or approximation in designing and implementing the control scheme. The stable control algorithm is derived based on Lyapunov stability theory. Its effectiveness is confirmed with simulation verification.

1. In chloralose-urethane anaesthetized cats, the dorsal cardiovascular reactive area (DCRA) in the parvocellular reticular nucleus dorsomedial to the facial nucleus, and the ventral cardiovascular reactive area (VCRA) ventromedial to the facial nucleus, were stimulated by microinjections of sodium glutamate (100-200 nmol) or electric current. 2. Stimulation of DCRA, with a long latency of 15-20 s, elicited a marked increase of blood flow in the contralateral femoral artery with little change to moderate increase in systemic arterial blood pressure (ABP). In the relatively dorsal portion of DCRA, however, a smaller increase of blood flow in the ipsilateral femoral artery was elicited. 3. On the other hand, stimulation of VCRA with a short latency (3-5s) evoked an increase of blood flow in both femoral arteries which was more prominent on the contralateral side. The responses were accompanied with decreases in the blood flow of other vascular beds with only a slight increase or minimal change in ABP. 4. The data suggest that DCRA and VCRA are both viscerotopically organized to alter the resistance of individual vascular beds for redistribution of blood flow.