Development of a method for the simultaneous determination of ionic nutrients in hydroponic solutions using cation-/anion-exchange chromatography with a neutral eluent.

Nutrient availability in hydroponic solutions must be accurately monitored to maintain crop productivity; however, few cost-effective, accurate, real-time, and long-term monitoring technologies have been developed. In this study, we describe the development and application of cation-/anion-exchange chromatography with a neutral eluent (20-mmol/L sodium formate, pH 7.87) for the simultaneous separation (within 50 min) of ionic nutrients, including K+, NH4+, NO2-, NO3-, and phosphate ion, in a hydroponic fertilizer solution. Using the neutral eluent avoided degradation of the separation column during precipitation of metal ion species, such as hydroxides, with an alkaline eluent and oxidation of NO2- to NO3- with an acidic eluent. The suitability of the current method for monitoring ionic components in a hydroponic fertilizer solution was confirmed. Based on our data, we propose a controlled fertilizer strategy to optimize fertilizer consumption and reduce the chemical load of drained fertilizer solutions.

Hemostasis using a covered self-expandable metal stent for pseudoaneurysm bleeding from the perihilar bile duct.

Although there are many reports of hemostasis with covered self-expandable metal stent (CSEMS) for bleeding from the papilla of Vater and the intrapapillary and distal bile duct, there are rare reports of its use for hemostasis in the perihilar bile duct. We report the case of a patient undergoing supportive care for perihilar cholangiocarcinoma with acute cholecystitis after side-by-side placement of uncovered SEMS for perihilar bile duct obstruction. Percutaneous transhepatic gallbladder aspiration was performed upon admission, and hematemesis occurred the next day. Since computed tomography scanning showed a pseudoaneurysm in the right uncovered SEMS, hemostasis by interventional radiology (IVR) was performed thrice for massive bleeding; however, hemostasis could not be achieved. When endoscopic retrograde cholangiopancreatography was performed for scrutiny and treatment of melena and increased hepatobiliary enzyme, the endoscopic visual field could not be secured by bleeding, and changes in hemodynamics were observed; thus, IVR was required, but it was difficult to perform. Since bleeding from the right bile duct was expected, hemostasis was performed using CSEMS. This is the first report of hemostasis performed by placing a covered SEMS for bleeding from a pseudoaneurysm of the intrahepatic bile duct.

Primary endoscopic bile duct stone removal for severe acute cholangitis: a retrospective study.

INTRODUCTION: While the Tokyo Guidelines 2018 suggest primary stone removal for mild to moderate cholangitis, a guideline for severe acute cholangitis is not mentioned. We, therefore, investigated the clinical outcomes of patients with severe acute cholangitis to confirm the usefulness and safety of primary stone removal. METHOD: This study included 104 severe acute cholangitis patients without gallstone pancreatitis diagnosed at our institution between January 2014 and December 2020. Patients with percutaneous transhepatic biliary drainage as the primary drainage, bile duct stenosis, and endoscopically unidentified bile duct stones were excluded from this study. The clinical results of 14 patients with primary stone removal (primary group) and 23 patients with elective stone removal (elective group) were then retrospectively examined (excluding abnormal values due to underlying diseases). RESULTS: Upon comparing the patient characteristics between groups, the elective group had significantly higher cardiovascular dysfunction (57% vs 7%; p = 0.004), septic shock (39% vs 0%; p = 0.006), disseminated intravascular coagulation treatment (57% vs 14%; p = 0.016), and positive blood cultures (91% vs 43%; p = 0.006) than those in the primary group. Endoscopic sphincterotomy for naïve papilla (90% vs 21%; p = 0.01) and endoscopic nasobiliary drainage (50% vs 9%; p = 0.014) were higher in the primary group, while endoscopic biliary stenting (7% vs 87%; p < 0.001) was lower than that in the elective group. DISCUSSION: There were no significant differences in adverse events or complete stone removal rates between the two groups. In the primary group, the period from the first endoscopic retrograde cholangiopancreatography to stone removal (0 days vs 12 days; p < 0.001) and hospitalization period (12 days vs 26 days; p = 0.012) were significantly shorter and the hospitalization cost ($7731 vs $18758; p < 0.001) was significantly lower than those in the elective group. CONCLUSION: If patients are appropriately selected, bile duct stones may be safely removed for the treatment of severe acute cholangitis.

Slow deformation event between large intraslab earthquakes at the Tonga Trench.

Slow deformations associated with a subducting slab can affect quasi-static displacements and seismicity over a wide range of depths. Here, we analyse the seismotectonic activities in the Tonga subduction zone, which is the world's most active area with regard to deep earthquakes. In our study, we combine data from global navigation satellite systems with an earthquake catalogue. We focus on the deep earthquakes that are below 400 km at the lower part of the Wadati-Benioff zone. We find that trenchward transient displacements and quiescence of deep earthquakes, in terms of background seismicity, were bounded in time by large intraslab earthquakes in 2009 and 2013. This "slow deformation event" between 2009 and 2013 may have been triggered by a distant and shallow M8.1 earthquake, which implies a slow slip event at the plate interface or a temporal acceleration of the subduction of the Pacific Plate. These findings provide new insights into the relationship between shallow and deep earthquakes in the subduction zone.

Prediction of the progression of walled-off necrosis in patients with acute pancreatitis on whole pancreatic perfusion CT.

BACKGROUND/PURPOSE: This study investigated whether measuring pancreatic blood volume (PBV) on whole pancreatic perfusion computed tomography (P-CT) can predict the progression of walled-off necrosis (WON) in patients with acute pancreatitis (AP). METHODS: A single-center, retrospective cohort study was conducted between December 2015 and December 2016. The participants were divided into two groups: 14 patients with WON and 15 patients without WON. PBV was measured within 72 hours after the diagnosis of AP, and the final diagnosis of WON was made by contrast-enhanced CT (CE-CT) or endoscopic ultrasonography (EUS) 4 weeks after the onset of AP. RESULTS: The minimum CT value did not differ significantly between the two groups. On the other hand, the minimum PBV was significantly lower in the WON group than in the without WON group (1.4 (0.9-9.9) vs 19.8 (8.2-21.7) mL/100 mL, respectively; P = .02). The cutoff value of the minimum PBV for WON was 16.5 mL/100 mL (sensitivity 100%, specificity 67%, AUC 0.85; P = .001). CONCLUSIONS: Whole pancreatic P-CT can evaluate pancreatic ischemia visually and quantitatively. The minimum PBV measurement on whole pancreatic P-CT within 72 hours after the diagnosis of AP contributes to the prediction of progression of WON.

Safety of endoscopic sphincterotomy in patients undergoing antithrombotic treatment: a retrospective study.

BACKGROUND: This study investigated the safety of endoscopic sphincterotomy in patients undergoing antithrombotic treatment. METHODS: From January 2014 to December 2016, a single-center retrospective study was conducted. Of the 80 patients with naïve papilla receiving antithrombotic treatment who underwent endoscopic sphincterotomy, 76 patients were retrospectively analyzed. We divided the participants into two groups as follows: 45 patients who discontinued antithrombotic treatment (discontinuation group) and 31 patients who continued antithrombotic treatment (continuation group). We evaluated the safety of endoscopic sphincterotomy in patients with naïve papilla who received antithrombotic treatment. RESULTS: The percentage of patients requiring emergency endoscopic retrograde cholangiopancreatography in the continuation group was significantly higher than that in the discontinuation group (55% vs 11%; p = 0.001). The incidence of adverse events did not differ significantly between the two groups. Neither bleeding nor perforation occurred in either group. The length of hospital stay did not differ significantly between the two groups. CONCLUSIONS: Endoscopic sphincterotomy in patients undergoing antithrombotic treatment may be safe if the guidelines for gastroenterological endoscopy in patients undergoing antithrombotic treatment are followed.

Endoscopic side-by-side uncovered self-expandable metal stent placement for malignant hilar biliary obstruction.

AIM: To investigate outcomes of endoscopic bilateral side-by-side placement across the papilla using 10-mm-diameter uncovered self-expandable metal stents for unresectable malignant hilar biliary obstruction. METHODS: We retrospectively analyzed 23 patients who underwent endoscopic biliary uncovered self-expandable metal stent placement for unresectable malignant hilar biliary obstruction between January 2015 and September 2016 at our institution. We performed endoscopic side-by-side placement across the papilla using 10-mm-diameter longer-model uncovered self-expandable metal stents. Outcomes included the technical and functional success rates, recurrent biliary obstruction rate, time to recurrent biliary obstruction, reintervention rate, and incidence of adverse events other than recurrent biliary obstruction. RESULTS: Of the 23 patients, 10 with malignant hilar biliary obstruction underwent endoscopic side-by-side uncovered self-expandable metal stent placement across the papilla (median age, 83 years; 6 men). The locations of malignant hilar biliary obstruction were Bismuth types II (n = 3), III (n = 3), and IV (n = 4). The median common bile duct diameter was 8 mm. The technical and functional success rates were 100% and 80%, respectively. Seven patients (70%) developed recurrent biliary obstruction because of stent occlusions, including early hemobilia in two patients and late tumor ingrowth in five patients. The median time to recurrent biliary obstruction was 66 (95% confidence interval: 29-483) days. Six patients (60%) required reintervention, and 1 (10%) underwent transcatheter arterial embolization for right hepatic arterial pseudoaneurysm. Early adverse events other than recurrent biliary obstruction occurred in four patients and late adverse event in one patient. CONCLUSION: Endoscopic side-by-side placement across the papilla using 10-mm-diameter uncovered self-expandable metal stents was technically feasible for unresectable malignant hilar biliary obstruction; however, it might be better to avoid this method for patients with malignant hilar biliary obstruction because of high recurrent biliary obstruction rate and shorter time to recurrent biliary obstruction.

Severe Acute Pancreatitis with Candida Endophthalmitis.

Severe acute pancreatitis (SAP) is a risk factor for candidemia. We report a case of candida endophthalmitis in a 67-year-old man who was admitted to a hospital due to SAP with poorly controlled diabetes. After treatment for SAP, he was diagnosed with candidemia and candida endophthalmitis. We chose appropriate antifungal agents based on the results of a bacterial culture test. After treatment, the disappearance of Candida albicans (C. albicans) from the blood stream was confirmed in blood cultures. In addition, exudative plaques consistent with a fungal infection disappeared. After a diagnosis of candidemia is made, it is important to administer appropriate antifungal therapy and perform frequent ophthalmologic examinations.

Side-by-side partially covered self-expandable metal stent placement for malignant hilar biliary obstruction.

BACKGROUND AND STUDY AIMS: This study investigated the feasibility of side-by-side (SBS) partially covered self-expandable metal stent (PCSEMS) placement for unresectable malignant hilar biliary obstruction (MHBO). PATIENTS AND METHODS: We retrospectively analyzed 33 patients from a single center who underwent endoscopic biliary drainage for unresectable MHBO from July 2013 to June 2015. In all patients with bilateral obstruction during complete bilateral intrahepatic cholangiograms, we performed endoscopic SBS placement of a 6-mm diameter PCSEMS using an 8-French delivery system. All patients underwent endoscopic sphincterotomy. Generally, patients with recurrent biliary obstruction (RBO) after stent placement underwent endoscopic reintervention. Our study outcomes included the technical and functional success rates, RBO rate, time to RBO (TRBO), reintervention rate, and incidence of adverse events. RESULTS: Seventeen patients with unresectable MHBO during complete bilateral intrahepatic cholangiograms underwent endoscopic SBS PCSEMS placement (median age, 78 years; men, 9). Lesions were Bismuth types II (n = 10), III (n = 1), and IV (n = 6), including 10 cholangiocarcinomas, 3 gallbladder cancers, and 4 metastatic cancers. In all patients, the PCSEMS was placed across the duodenal papilla. The technical and functional success rates were 100 % and 82 %, respectively. The median procedure time was 43 minutes (interquartile range [IQR]: 36 - 52 minutes). Twelve patients had RBO (71 %), including 9 stent occlusions due to sludge and 3 stent migrations. The median TRBO was 79 days (IQR: 58 - 156 days) during the follow-up period (median 192 days [IQR: 88 - 551 days]). The median TRBO of patients with Bismuth type II lesions was significantly longer than that of patients with Bismuth types III and IV lesions (87 days [IQR: 70 - 244 days] vs. 54 days [IQR: 35 - 100 days]; P  = 0.030). Thirteen patients (76 %) required endoscopic reintervention. Endoscopic stent removal was possible in 6 patients without tumor ingrowth into the uncovered distal part of the stent. One late adverse event (≥ 31 days) occurred (cholangitis). CONCLUSIONS: Endoscopic SBS placement of a PCSEMS was feasible in patients with unresectable MHBO. Additionally, reinterventional stent removal was possible in the absence of tumor ingrowth.

Feasibility of initial endoscopic common bile duct stone removal in patients with acute cholangitis.

AIM: To investigate the feasibility of initial endoscopic common bile duct (CBD) stone removal in patients with acute cholangitis (AC). METHODS: A single-center, retrospective study was conducted between April 2013 and December 2014 and was approved by the Medical Ethics Committee at our institution. Written informed consent was obtained from each patient prior to the procedure. The cohort comprised 31 AC patients with CBD stones who underwent endoscopic biliary drainage (EBD) for naïve papilla within 48 h after AC onset. We retrospectively divided the participants into two groups: 19 patients with initial endoscopic CBD stone removal (initial group) and 12 patients with delayed endoscopic CBD stone removal (delayed group). We evaluated the feasibility of initial endoscopic CBD stone removal in patients with AC. RESULTS: We observed no significant differences between the groups regarding patient characteristics. According to the assessments based on the Tokyo Guidelines, the AC severity of patients with initial endoscopic CBD stone removal was mild to moderate. The use of antithrombotic agents before EBD was less frequent in the initial group than in the delayed group (11% vs 58%, respectively; P = 0.004). All the patients underwent successful endoscopic CBD stone removal and adverse events did not differ significantly between the groups. The number of endoscopic retrograde cholangiopancreatography procedures was significantly lower in the initial group than in the delayed group [median (interquartile range) 1 (1-1) vs 2 (2-2), respectively; P < 0.001]. The length of hospital stay was significantly shorter for the initial group than for the delayed group [10 (9-15) vs 17 (14-20), respectively; P = 0.010]. CONCLUSION: Initial endoscopic CBD stone removal in patients with AC may be feasible when AC severity and the use of antithrombotic agents are carefully considered.

Observation of Earth's free oscillation by dense GPS array: after the 2011 Tohoku megathrust earthquake.

Day-scale Earth's free oscillation after large earthquakes has been detected by underground instruments such as strainmeters, gravimeters and seismometers, to investigate Earth's internal structure, geodynamics, and source properties of earthquakes. Here we show that Global Positioning System (GPS) can also detect the signals of the Earth's free oscillation. A dense GPS array in Japan (GEONET) recorded the surface deformation following the 2011 Tohoku megathrust earthquake. A simple array analysis over 300 stations reduces local noise in GPS time series. We find that the dense GPS array truly detected both spheroidal and toroidal fundamental modes in three-direction displacement. This new tool has a strong potential to investigate the free oscillations particularly in low-frequency bands.