Perforation of descending colonic cancer as a rare cause of gas gangrene of the lower limb in an 80-year-old female: a case report.

Gas gangrene is a rare, severe gas-producing infection that can be related to colorectal cancer. Gas gangrene can be confirmed by radiologic findings and crepitation on touch. Spontaneous gas gangrene can be associated with colorectal cancer. An 80-year-old female complaint about a sudden abdominal pain, accompanied with progressive swelling pain in thigh and fever. Diagnosis based on assessment findings were gas gangrene and descending colonic cancer perforation. Emergency surgery was performed for debridement and drainage, followed by vacuum sealing drainage (VSD) with polyurethane (PU). Two more surgical interventions were given before the colonic tumor surgery. The patient recovered well in the long-term follow-up. This report demonstrates the diagnosis, treatment, and management of a successful case of gas gangrene caused by perforation of descending colonic cancer. Accurate preoperative diagnosis and reasonable use of VSD (PU) material played an important role in the treatment of this case.

The fault detection of transmitting current encoded by m-sequence using triple-correlation function in helicopter-borne electromagnetic method.

An m-sequence is applied to the helicopter-borne electromagnetic method system for the first time, and there are many problems to be solved, one of which is the detection of the quality of the transmitting current waveform, which directly affects the resource survey results. In this research, we found that the triple-correlation function (TCF) can reveal the bit integrity characteristics of the m-sequence encoded transmitting current. On this basis, this paper proposes to extract the three-dimensional information of the normalized TCF plot by using a peak detection method and, then, proposes to use a dual-threshold method to clarify the detection results. The whole process realizes the fault detection of the transmitting current waveform. We propose a reasonable transmitting current modeling method and conduct 1200 random experiments in 12 groups. The statistics of the experimental results show that when the number of missing bits is 1, 2, 4, and 8, the fault detection accuracy can reach more than 83%. A comparative experiment using the Field Programmable Gate Array. in the laboratory validates the feasibility of the fault detection method. This method is beneficial to improve the quality of detection data and avoid economic losses caused by invalid detection flights.