RESUMEN
The traditional measurement method can't achieve real-time monitoring of soil moisture content (SMC) within a two-dimensional area. To solve the above problems, we propose a rapid SMC monitoring method for two-dimensional area based on distributed acoustic sensing (DAS). DAS demodulates the backward Rayleigh scattering signal containing seismic wave sound velocity information from the active seismic source. The folding ruler approximation is employed to calculate the sound velocity of the soil, which is then inverted to determine the soil moisture content. The experiment measured the soil within a two-dimensional area formed by the seismic source and the acoustic sensing optical cable. The sensing optical cable and the active seismic source are organized into a two-dimensional area and the measurement range is 3 × 10 m with 33 points. The SMC ranges from 15% to 40%. The experiment shows that the absolute error between the measured values obtained by DAS and the water cut meter is 7%. This experiment verifies the feasibility of using the Rayleigh scattering properties to invert SMC and provides a new method for real-time monitoring of SMC in a large area.
RESUMEN
RATIONALE: Choledochal cysts are a risk factor for the development of cholangiocarcinoma. Hence, complete surgical excision is the preferred treatment in most cases. However, cholangiocarcinoma still can develop from the remnant biliary system after surgical excision. Signet-ring cell carcinoma is a rare type of cancer of the biliary system, and the occurrence of signet-ring cell carcinoma after surgical excision of choledochal cysts has not been reported in the English literature to date. PATIENT CONCERNS: We report a case of a 32-year-old woman who presented with a 1-month history of abdominal pain,obstructive jaundice, itching, and fever. The patient had undergone choledochal cyst excision and Roux-en-Y hepatico-jejunostomy 25 years previously and had now developed signet-ring cell carcinoma along with cholangiocarcinoma at the anastomotic site. DIAGNOSES:: signet-ring cell carcinoma along with cholangiocarcinoma. INTERVENTIONS: Interventions included laparotomy with evacuation,blood transfusion,and other adjuvant therapy. OUTCOMES: The patient died five months later. LESSONS: Surgery is the best treatment for CCCs, and the surgeon should try to remove as much as of the bile duct cyst as possible.
