Abstract:A new H -ion source has been installed successfully and will be used to serve the China Spallation Neutron Source (CSNS). In this paper, we report various components of the ion source, including discharge chamber, temperature， cooling system, extraction electrodes, analyzing magnet, remote control system and so on. Compared to the previous experimental ion source, some improvements have been made to make the ion source more compact and convenient. In the present arrangement, the Penning field is generated by a pair of pole tip extensions on the 90°analyzing magnet instead of by a separate circuit. For the remote control system, F3RP61-2L is applied to the accelerator online control system for the first time. In the running of the ion source, a stable pulse H -beam with a current of 50 mA at an energy of 50 keV is produced. The extraction frequency and pulse width is 25 Hz and 500 s, respectively. Furthermore, an emittance scanner has been installed and measurements are in progress.

Abstract. The goal of this study was to evaluate the effect of the Na + /H + exchanger-1 (NHE-1) antisense gene on drugresistant human small cell lung cancer (SCLC) cell proliferation and apoptosis. A recombinant NHE-1 antisense gene was transfected into drug-resistant human SCLC H446/CDDP cells. Intracellular pH (pHi) was measured with fluorescence spectrophotometry. Cell proliferation was assayed cytometrically, and expression of the apoptosis gene caspase-3 was assayed using immunohistochemistry. Apoptosis and the cell cycles were imaged using a flow cytometer. pHi decreased significantly in transfected cells compared with control cells transfected with an empty vector (6.86±0.01 and 7.25±0.02, respectively, P<0.01). Cell proliferation began to decrease 48 h after antisense gene transfection, and the expression of the caspase-3 was stronger in transfected cells compared to the control group. The drug resistant exponent was significantly decreased (P<0.01), and there were more cells in G1 in the transfected group compared to the control group (70 and 57%, respectively, P<0.05). The rate of apoptosis in transfected cells was significantly higher than in the control group (12.18±1.86 and 2.37±0.33%, respectively, P<0.01). The NHE-1 antisense gene was able to induce drugresistant human SCLC H446/CDDP cells to become acidified and apoptotic, which could provide a novel therapy for multidrug resistance SCLC. IntroductionSmall cell lung cancer (SCLC) is a non-resectable and highly metastatic neoplastic disease, accounting for about 20% of all lung cancers (1). It is particularly aggressive and has a poor prognosis, with the 5-year survival rate at diagnosis rarely exceeding 10% (2). SCLC is a chemosensitive and radiosensitive disease; chemotherapy for SCLC typically involves a combination of etoposide, doxorubicin, vincristine, paclitaxel, and platinum-based regimens (3-5). First-line combination chemotherapy (with or without regional radiotherapy) induces a positive response in 70% of patients, with 50% of patients showing complete remission (6,7). However, 90% of these complete remission patients relapse with multidrug resistant tumours, making chemotherapy ineffective (8,9). Multidrug resistance is a serious clinical problem, which often severely limits the effectiveness of cancer chemotherapy (10). Thus, treating SCLC presents a significant clinical challenge.However, an effective way to treat SCLC multi-drug resistance has been reported (11). NHE-1 can directly interact with other regulatory cellular signaling pathways and is a multifaceted regulator of cell migration, proliferation, and cell death (12-14). The Na + /H + exchanger NHE-1 isoform is expressed ubiquitously and plays the crucial role of regulating intracellular pH by catalyzing the exchange of one extracellular sodium ion against one intracellular proton. Maintaining a steady-state intracellular pH during physiological conditions requires the continuous cellular export of acidic equivalents (15,16). Na + /H + exchangers (NHE) are membrane transport...

An accelerator-based Boron Neutron Capture Therapy (BNCT) facility has been built at the campus of China Spallation Neutron Source (CSNS). To upgrade it, a Drift Tube Linac (DTL) is designed to provide a 40 mA, 25% duty factor, 10.1 MeV beam for the target. Two opposing power couplers are employed to deliver forward peak power up to 640 kW for the beam and DTL cavity. A new coaxial power coupler with a single Tristan type window is designed to meet the power and coupling coefficient requirements. In this paper, the detailed RF optimization process of the coupler is described. According to the RF simulation results, the multipacting (MP) phenomenon at critical locations is simulated by the CST PS (Particle Studio). Simulations of thermal and mechanical are also carried out, the cooling design to provide a large margin for RF heating is performed based on the simulation results.