Appendiceal bleeding: A case report.

Background: Acute lower gastrointestinal bleeding is common in clinical practice, and the colon is responsible for the majority of cases. However, appendiceal bleeding is an extremely rare cause. Appendiceal bleeding due to vascular diseases, such as angiodysplasia and Dieulafoy's lesion, may result in massive lower gastrointestinal bleeding.

A repetitive S-band long-pulse relativistic backward-wave oscillator.

This paper presents both numerical and experimental studies of a repetitive S-band long-pulse relativistic backward-wave oscillator. The dispersion relation curve of the main slow-wave structure is given by the numerical calculation. Experimental results show that a 1 GW microwaves with pulse duration of about 100 ns (full width of half magnitude) under 10 Hz repetitive operation mode are obtained.