Estimation of Unsaturated hydraulic parameters by In-situ technique

In-situ determination of fundamental hydraulic parameters like variably saturated hydraulic conductivity (K(FS)) and the matric flux potential (Φ(m)) provides a foundation from which several other unsaturated soil parameters can be estimated, namely the Alpha (α*) parameter. This Alpha parameter is the one of the components of 3D unsaturated flow in vadose zone and its value is the measure of the capillary component of unsaturated flow pattern. Here an in-situ technique, Pressure Infiltrometer is introduced to record the steady flow rate applying a constant positive head on an unsaturated soil surface. The aim of this paper is to check the shape factor of 3D flow geometry and to find out its sensitivity on other unsaturated hydraulic parameters and to find out the influence of Alpha parameters on the results of the in-situ estimation of field-saturated hydraulic conductivity

Evanescently coupled topological ring-waveguide systems for chip-scale ultrahigh frequency phononic circuits

Topological phononics enabling backscattering-immune transport is expected to improve the performance of electromechanical systems for classical and quantum information technologies. Nonetheless, most of the previous demonstrations utilized macroscale and low-frequency structures and thus offered little experimental insight into ultrahigh frequency phonon transport, especially in chip-scale circuits. Here, we report microwave phonon transmissions in a microscopic topological ring-waveguide coupled system, which is an important building block for wave-based signal processing. The elastic waves in the topological waveguide evanescently couple to the ring resonator, while maintaining the valley pseudospin polarization. The resultant waves are robust to backscattering even in the tiny hexagonal ring, generating a resonant phonon circulation. Furthermore, the evanescently coupled structure allows for a critical coupling, where valley-dependent ring-waveguide interference enables blocking of the topological edge transmission. Our demonstrations reveal the capability of using topological phenomena to manipulate ultrahigh frequency elastic waves in intricate phononic circuits for classical and quantum signal-processing applications.Comment: 13 pages, 9 figure

Evaluation of Preoperative Magnetic Resonance Cholangiopancreatography in Acute Cholecystitis to Predict Technical Difficulties in Laparoscopic Cholecystectomy

Magnetic resonance cholangiopancreatography (MRCP) is a non-invasive imaging technique that provides high-quality visualization of the biliary tree, including the gallbladder. This study aimed to evaluate the useful-ness of preoperative MRCP for acute cholecystitis in predicting technical difficulties during laparoscopic chole-cystectomy (LC). A total of 168 patients who underwent LC with preoperative MRCP were enrolled in this study. Patients were divided into two groups according to preoperative MRCP findings: the visualized group (n = 126), in which the entire gallbladder could be visualized; and the non-visualized group (n = 42), in which the entire gallbladder could not be visualized. The perioperative characteristics and postoperative complica-tions of the two groups were retrospectively analyzed. Operation time was longer in the non-visualized group (median 101.5 vs. 143.5 min; p < 0.001). The non-visualized group had significantly more intraoperative blood loss than the visualized group (median 5 vs. 10 g; p = 0.05). The rate of conversion to open cholecystectomy was significantly higher in the non-visualized group (1.6 vs. 9.5%; p = 0.03). In conclusion, patients in the non- visualized group showed higher difficulty in performance of LC. Our MRCP-based classification is a simple and effective means of predicting difficulties in performing LC for acute cholecystitis

Fluid collection and pancreatic fistula after pancreaticoduodenectomy

Background: Although postoperative abdominal fluid collection (POFC) is an important predictive factor for clinically relevant postoperative pancreatic fistula (CR-POPF), many patients are asymptomatic and resolve spontaneously. Triple-drug therapy consisting of gabexate mesylate, octreotide, and carbapenem antibiotics has been used at our institution to prevent pancreatic fistula after pancreatectomy. The present study aimed to evaluate the management and outcomes of patients with POFC and to determine the efficacy of triple-drug therapy to prevent CR-POPF after pancreaticoduodenectomy (PD).Methods: From 2016 to 2021, 125 patients who underwent PD were retrospectively analyzed to determine their postoperative fluid collection status. Triple-drug therapy was administered to patients who showed high amylase levels in their drainage (> 10,000 IU/L) on POD 1, 3, or 5, and who had any clinical symptoms associated with POFC.Results: The overall rate of POFC was 26% (n=33). Among these patients, CR-POPF developed in 16 patients (48%). There was no CR-POPF patient in the NO-POFC patient group. Triple-drug therapy was performed for 30 patients according to a preexisting treatment algorithm. Among these 30 patients, there were 23 POFC and 7 No-POFC patients. Twelve (52%) of the POFC patients developed CR-POPF despite treatment with triple-drug therapy. There were no CR-POPF patients in the NoPOFC patient group.Conclusions: Although POFC after PD is an important finding for CR-POPF, it does not necessarily develop into CR-POPF. The administration of triple-drug therapy is effective for the prevention of CR-POPF in cases without POFC fluid drainage aswell as in those with POFC

Synchronous Total Occlusion of the Celiac Axis and Superior Mesenteric Artery: An Autopsy Case

Acute mesenteric ischemia (AMI) is often caused by superior mesenteric artery (SMA) embolization. We report a rare case of synchronous celiac axis and SMA embolization in an elderly woman with initially mild abdominal pain. Ultimately, a second contrast-enhanced computed tomography revealed extensive necrosis from the stomach to the transverse colon together with liver ischemia due to hours of occlusion. Multiorgan failure made palliation the only option, and she died the following evening. Autopsy revealed a fragile atherosclerosis-asso-ciated thrombus. Careful examination and repeat diagnostic tests should be performed in patients with mild abdominal symptoms at risk for AMI

A Case of Intraductal Papillary Neoplasm of the Bile Duct with Stromal Invasion

Intraductal papillary neoplasm of the bile duct (IPNB) represents biliary papillary tumors mainly growing and is considered to be of relatively low-grade malignancy. Here we report a case of IPNB in whom the poorly differentiated component deeply infiltrated the bile duct wall. A 77-year-old male had an invasive carcinoma of the bile duct 3 cm in size. He underwent right hemihepatectomy with combined resection of the extrahepatic bile duct. Papillary growing tumor was observed in the common bile duct and the right posterior Glisson's pedicle was invaded. Histologic finding showed papillary adenocarcinoma in the surface layer superficially extending to the epithelium of the surrounding bile duct. In the subserosal layer, the tumor represented poorly differentiated adenocarcinoma. The tumor was diagnosed as invasive bile duct carcinoma arising from IPNB

Portal Vein Anastomosis with Parachute Method in Hepatectomy and Pancreatectomy

In advanced cancers of hepatobiliary and pancreatic lesions, major vascular resection and reconstruction are necessary to accomplish curative resection. Stenosis of vascular anastomosis is a concern in case of portal or superior mesenteric venous anastomosis with different vascular calibers. We attempted to apply parachute anastomosis in such a situation, which has often been used in the field of cardiovascular surgery. We applied this procedure in 4 cases of two hepatectomies in intrahepatic cholangiocarcinomas and two pancreatectomies in pancreatic carcinomas, in which combined vascular resection was necessary. After anastomosis, the orifice of anastomotic veins was well matched and did not show stenosis or poor blood flow on ultrasonographic examination. Parachute anastomosis in the portal or superior mesenteric vein is a useful procedure to prevent vascular stenosis, particularly in case of anastomosis with different calibers