PURPOSE: To demonstrate the relationship between of sphingosine-1-phosphate (S1P) expression and subarachnoid hemorrhage (SAH). METHODS: The basilar arteries from a "double-hemorrhage" rabbit model of SAH were used to investigate the relation between S1P expression and SAH. Various symptoms, including blood clots, basilar artery cross-sectional area, and S1P phosphatase expression were measured at day 3, 5, 7, 9. RESULTS: The expression of S1P was enhanced in the cerebral vasospasm after subarachnoid hemorrhage in the rabbits. And S1P expression was consistent with the basilar artery cross-sectional area changes at day 3, 5, 7, 9. CONCLUSION: Sphingosine-1-phosphate expression in the cerebral arterial may be a new indicator in the development of cerebral vasospasm after subarachnoid hemorrhage and provide a new therapeutic method for SAH.

A wideband patch antenna is proposed. By using the dual-layer patch configuration and modified L-strip feed technique, the impedance bandwidth of the patch antenna for VSWR<1.2 is broadened to 22% with respect to 900 MHz, which is superior to the other available patch antennas. In addition, by means of the modified L-shaped strip, the high cross polarization levels of the proposed antenna are suppressed effectively. Simulation results are compared with the measurements, and a good agreement is obtained. The measurements show that the antenna has a low cross-polarization level (<-20dB) and an acceptable gain level (~9dBi) across the operating bandwidth. At last, a parametric study and a design guideline of the proposed antenna are also presented to facilitate the design and optimization processes for engineers.