Study on the Reduction Process of Iron Oxide Pellets in Isothermal Fixed Bed

A mathematical model for the isothermal fixed bed and one of the numerical calculating method for this model are presented in this paper. The reaction rate accepted in this model is determined on the basis of the rate observed for single iron oxide pellet. In order to clarify the availability of the mathematical model for analyzing the metallurgical reactors, change in the average fractional reduction over the whole bed with the progress of time was observed during the reduction of iron oxide pellets with CO and H_2 by the use of the experimental fixed bed. The observed data are in good agreement with the calculated curves except in the case where the pellets cracked badly during the reduction. It is, therefore, found that the distributions of process variables in isothermal fixed bed can be estimated with the considerable accuracy by the model mentioned above, and that the reaction rates of pellets with CO and H_2 used in this paper are expected to be available for the process analysis of metallurgical reactors

Reduction Rate of Iron Oxide Pellets with Hydrogen

For analyzing the reduction process in the metallurgical reactor, especially in blast furnace, the reduction rates of hematite pellet and iron oxide pellet pre-reduced to wustite, "wustite pellet", were expressed by a mathematical model and the rate parameters thereof were determined. An unreacted core model was applied to simulate the hydrogen reduction of iron oxide pellets within the temperature range from 850 to 1, 150℃. Comparison of the rate constant of chemical reaction and its activation energy of hematite pellet with those of wustite pellet did not show significant difference. The pellets used had an activation energy of about 21 to 26 kcal/mol. In the macro- and microscopic observation of iron oxide pellets during the reduction, the reaction proceeded topochemically. A sharp interface was found between wustite and iron phase in the case of hematite pellet, whereas reaction zone of about 300μ was found in the case of wustite pellet. The calculated reduction curves almost agreed with the observed values with the changes of temperatures, diameters of the pellet and concentrations of reducing gas. These calculated curves further agreed with the values observed by altering one of the experimental conditions during reduction

Multiple Hepatolithiasis Following Hepaticojejunostomy Successfully Treated with Left Hemihepatectomy and Double Hepaticojejunostomy Reconstruction

Surgical intervention for hepatolithiasis following hepaticojejunostomy (HJ) has rarely been reported. Herein, we present a case of post-HJ multiple hepatolithiasis treated with left hemihepatectomy with double HJ reconstruction. A 72-year-old woman who had undergone HJ for iatrogenic bile duct injury developed repeated cholangitis due to complicated hepatolithiasis accompanied by an atrophied left hepatic lobe and HJ stricture. Since endoscopic intervention was unsuccessful, the patient underwent left hemihepatectomy with HJ re-anastomoses of the common hepatic duct and left hepatic duct (double HJ technique). The double HJ technique with hepatectomy can be a useful option for treating complicated hepatolithiasis following HJ

Left Hemihepatectomy for Hepatocellular Carcinoma Following Esophagectomy with Retrosternal Gastric Tube Reconstruction for Esophageal Cancer

Approximately 4% of patients with esophageal cancer develop a second primary malignancy in the upper gastrointestinal trunk. However, hepatectomy following esophagectomy for esophageal cancer has rarely been reported. We report the case of a 70-year-old man who underwent an esophagectomy for esophageal cancer with retrosternal gastric tube reconstruction. Nine years later, he developed hepatocellular carcinoma with tumor thrombus involving the left portal vein, and was successfully treated with left hemihepatectomy. Special attention should be paid to avoiding incidental injury of the gastric tube as well as the right gastroepiploic artery during the hepatectomy

Long-term activation of anti-tumor immunity in pancreatic cancer by a p53-expressing telomerase-specific oncolytic adenovirus

Background: Pancreatic cancer is an aggressive, immunologically “cold” tumor. Oncolytic virotherapy is a promising treatment to overcome this problem. We developed a telomerase-specific oncolytic adenovirus armed with p53 gene (OBP-702). Methods: We investigated the efficacy of OBP-702 for pancreatic cancer, focusing on its long-term effects via long-lived memory CD8 + T cells including tissue-resident memory T cells (TRMs) and effector memory T cells (TEMs) differentiated from effector memory precursor cells (TEMps). Results: First, in vitro, OBP-702 significantly induced adenosine triphosphate (ATP), which is important for memory T cell establishment. Next, in vivo, OBP-702 local treatment to murine pancreatic PAN02 tumors increased TEMps via ATP induction from tumors and IL-15Rα induction from macrophages, leading to TRM and TEM induction. Activation of these memory T cells by OBP-702 was also maintained in combination with gemcitabine+nab-paclitaxel (GN) in a PAN02 bilateral tumor model, and GN + OBP-702 showed significant anti-tumor effects and increased TRMs in OBP-702-uninjected tumors. Finally, in a neoadjuvant model, in which PAN02 cells were re-inoculated after resection of treated-PAN02 tumors, GN + OBP-702 provided long-term anti-tumor effects even after tumor resection. Conclusion: OBP-702 can be a long-term immunostimulant with sustained anti-tumor effects on immunologically cold pancreatic cancer

Local oncolytic adenovirotherapy produces an abscopal effect via tumor-derived extracellular vesicles

Extracellular vesicles (EVs) play important roles in various intercellular communication processes. The abscopal effect is an interesting phenomenon in cancer treatment, in which immune activation is generally considered a main factor. We previously developed a telomerase-specific oncolytic adenovirus, Telomelysin (OBP-301), and occasionally observed therapeutic effects on distal tumors after local treatment in immunodeficient mice. In this study, we hypothesized that EVs may be involved in the abscopal effect of OBP-301. EVs isolated from the supernatant of HCT116 human colon carcinoma cells treated with OBP-301 were confirmed to contain OBP-301, and they showed cytotoxic activity (apoptosis and autophagy) similar to OBP-301. In bilateral subcutaneous HCT116 and CT26 tumor models, intratumoral administration of OBP-301 produced potent antitumor effects on tumors that were not directly treated with OBP-301, involving direct mediation by tumor-derived EVs containing OBP-301. This indicates that immune activation is not the main factor in this abscopal effect. Moreover, tumor-derived EVs exhibited high tumor tropism in orthotopic HCT116 rectal tumors, in which adenovirus E1A and adenovirus type 5 proteins were observed in metastatic liver tumors after localized rectal tumor treatment. In conclusion, local treatment with OBP-301 has the potential to produce abscopal effects via tumor-derived EVs

Treatment of multiple liver metastasis from gastric carcinoma

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