The therapeutic effects on U87 and SAS cells using Proton Linac based Boron Neutron Capture Therapy in Korea.

A proton linac based boron neutron capture therapy system (A-BNCT, 10MeV, 4mA) was successfully developed in Korea. We performed in vitro experiments with U87 and SAS cells and revealed the efficacy of a binary therapy BNCT using epithermal neutrons and boronophenylalanine (BPA). The results revealed that BNCT showed cancer cell selectivity and caused cell death. Further in vitro studies can be a valuable method to characterize an A-BNCT system. We expect BNCT to become a treatment option for cancer patients.

The Anti-Tumor Effect of Boron Neutron Capture Therapy in Glioblastoma Subcutaneous Xenograft Model Using the Proton Linear Accelerator-Based BNCT System in Korea.

Boron neutron capture therapy (BNCT) is a radiation therapy that selectively kills cancer cells and is being actively researched and developed around the world. In Korea, development of the proton linear accelerator-based BNCT system has completed development, and its anti-cancer effect in the U-87 MG subcutaneous xenograft model has been evaluated. To evaluate the efficacy of BNCT, we measured 10B-enriched boronophenylalanine (BPA) uptake in U-87 MG, FaDu, and SAS cells and evaluated cell viability by clonogenic assays. In addition, the boron concentration in the tumor, blood, and skin on the U-87 MG xenograft model was measured, and the tumor volume was measured for 4 weeks after BNCT. In vitro, the intracellular boron concentration was highest in the order of SAS, FaDu, and U-87 MG, and cell survival fractions decreased depending on the BPA treatment concentration and neutron irradiation dose. In vivo, the tumor volume was significantly decreased in the BNCT group compared to the control group. This study confirmed the anti-cancer effect of BNCT in the U-87 MG subcutaneous xenograft model. It is expected that the proton linear accelerator-based BNCT system developed in Korea will be a new option for radiation therapy for cancer treatment.

Experimental Study on the Shear Strength of Reinforced Concrete Beams with Various Integrated Shear Reinforcements.

The purpose of this study was to evaluate the shear performance of concrete beams with integrated shear reinforcements made of steel plates and rebar bent in an N shape (N-type rebar), and to evaluate the applicability of the current relevant design standards. For this purpose, four concrete beam specimens were manufactured. Four-point loading tests were performed with all the specimens. The experiments confirmed that both types of shear reinforcements had a shear-reinforcing effect (an about 60% increase in shear strength), but the N-type rebar did not exceed the nominal shear strength, probably because the rebar did not yield sufficiently. A sufficient number of steel-plate-type shear reinforcements yielded in the shear crack. When evaluating the shear performance of a new shear reinforcement, it is necessary to calculate the design strength by actually reflecting whether the shear reinforcements' yields are due to the angle of the diagonal crack. Calculating the shear contribution based on the strain of the shear reinforcements and comparing this shear strength with those five design standards, the shear strength of the shear reinforcements were evaluated conservatively. It is considered that there will be no problem in structural safety even if the shear design is carried out according to the current design standards.