[en] Occupational and environmental exposure to arsenic (III) and chromium VI (Cr(VI)) have been confirmed to cause lung cancer. Mechanisms of these metals carcinogenesis are still under investigation. Selection of cell lines to be used is essential for the studies. Human bronchial epithelial BEAS-2B cells are the cells to be utilized by most of scientists. However, due to p53 missense mutation (CCG → TCG) at codon 47 and the codon 72 polymorphism (CGC → CCC) in BEAS-2B cells, its usage has frequently been questioned. The present study has examined activity and expression of 53 and its downstream target protein p21 upon acute or chronic exposure of BEAS-2B cells to arsenic and Cr(VI). The results show that short-term exposure of BEAS-2B cells to arsenic or Cr(VI) was able to activate both p53 and p21. Chronic exposure of BEAS-2B cells to these two metals caused malignant cell transformation and tumorigenesis. In arsenic-transformed BEAS-2B cells reductions in p53 promoter activity, mRNA expression, and phosphorylation of p53 at Ser392 were observed, while the total p53 protein level remained the same compared to those in passage-matched parent ones. p21 promoter activity and expression were decreased in arsenic-transformed cells. Cr(VI)-transformed cells exhibit elevated p53 promoter activity, mRNA expression, and phosphorylation at Ser15, but reduced phosphorylation at Ser392 and total p53 protein level compared to passage-matched parent ones. p21 promoter activity and expression were elevated in Cr(VI)-transformed cells. These results demonstrate that p53 is able to respond to exposure of arsenic or Cr(VI), suggesting that BEAS-2B cells are an appropriate in vitro model to investigate arsenic or Cr(VI) induced lung cancer. - Highlights: • Short-term exposure of BEAS-2B cells to arsenic or Cr(VI) activates p53 and p21. • Chronic exposure of BEAS-2B cells to arsenic or Cr(VI) causes cell transformation and tumorigenesis. • Arsenic-transformed cells exhibit reduced activities of p53 and p21. • Cr(VI)-transformed cells exhibit increased activities of p53 and p21

[en] Recently we measured with the Modified Three Gradient Method (MTGM) the beam emittance of an injector constructed in 2012, which was designed to provide a 2.4 kA, 2.6 MeV electron beam. The MTGM is a non-intercept indirect method, which is based on the three gradient type measurements of beam profiles and subsequent data processing which helps to get the least square solution to the beam emittance. Beam profiles under different currents of guiding coil are measured using Cerenkov radiation given off by a piece of quartz glass in the beam tube, which is recorded with a CCD camera. MTGM Code is developed to realize the data fitting as well as beam transport simulation, in which both the σ matrix method and the numerical solution of root-mean-square beam envelope equation are used. The error is also analyzed. (authors)

[en] The process of emittance increase in proton radiography is analyzed. A radiographic system is designed, and based on it the factors affecting emittance increase are studied with theoretical analysis and Monte Carlo simulation. The results show that the extracted emittance from the accelerator is neglectable for high energy proton radiography, and cannot be neglected for medium energy proton radiography. The extracted emittance could be reduced through decreasing the thickness of the diffuser and enhancing the focusing ability of the accelerator's extraction system. (authors)

[en] Objective: To investigate the clinical value of combined test of serum CA₁₉₉ and CA₅₀ levels in the diagnosis and prognosis of patients with pancreatic cancer. Methods: Serum levels of CA₁₉₉ and CA₅₀ in 40 cases of pancreatic cancer, 20 cases of chronic pancreatitis and 30 normal controls were detected by radioimmunoassay. Results: Serum CA₁₉₉ and CA₅₀ levels in pancreatic cancer patients were significantly higher than those in normal controls and chronic pancreatitis patients (P < 0.01). If serum CA₁₉₉ and CA₅₀ were detected simultaneously, the sensitivity, specificity and accuracy of diagnosis of pancreatic cancer could be improved. Serum CA₁₉₉ and CA₅₀ levels in cancer patients with lymph node metastasis were much higher than those without lymph node metastasis (P < 0.05). Conclusion: Serum CA₁₉₉ and CA₅₀ detected simultaneously could improve the sensitivity and accuracy in diagnosis of pancreatic cancer. The changes of serum CA₁₉₉ and CA₅₀ level were helpful to predict whether metastasis or recurrence had occurred

[en] Objective: To investigate the effect of elemene on the radiosensitivity of A549 cells and its possible molecular mechanism. Methods: The effect of radiosensitivity was detected by colony forming assay. The protein expressions of DNA-PKcs, Bcl-2 and P53 were detected with Western blot. The correlation between the protein expression of DNA-PKcs and Bcl-2, DNA-PKcs and P53 was analyzed. Results: Elemene had radiosensitizing effect on A549 cells, with the SER_D0 and SER_Dq 1.54 ± 0.20 and 1.43±0.15, respectively for 10 μg/ml elemene, and 1.63 ±0.32 and 1.75 ±0.19, respectively for 20 μg/ml elemene. Compared with irradiation group, the expression of DNA-PKcs was reduced significantly in 10, 20 μg/ml elemene combined with radiation group (t=7.52, 8.33, P<0.05), so was for Bcl-2 (t=10.74, 11.33, P<0.05). The expression of P53 protein increased significantly (t=-9.25, 7.66, P<0.05). There was a remarkable negative correlation between the expression of DNA-PKcs and P53 (r=-0.569, P<0.05), and a remarkable positive correlation between DNA-PKcs and Bcl-2 (r=0.755, P<0.05 ). Conclusions: Elemene has radiosensitizing effect on A549 cells, which might be related to down-regulation of DNA-PKcs gene expression, up-regulation of P53 and down-regulation of Bcl-2. (authors)

[en] A 750 keV, 201.25 MHz radio frequency quadrupole accelerator was designed as the injector of the Beijing proton linac. The beam dynamics study of this accelerator is described. The main parameters and results of two designs are presented. The influences of non-ideal conditions of parameters such as energy dispersion, emittance, Twiss parameters, input current and energy on beam transmission efficiency are analyzed. The similarities and differences of the two designs are shown. The results of the beam dynamics simulation show that the two designs both satisfy the physics requirement. (authors)

[en] The RF design of a 201.25 MHz, 750 keV RFQ injector is described. A four-rod structure is chosen for the RF design. The essential parameters are obtained from the beam dynamics design. The structure parameters, including the height, width, thickness, distance, shape of supporting arms, radius of outer cavity, are optimized by numerical simulation. When the inter-electrode voltage is 80 kV, the peak power loss is 115.95 kW, the dipole factor is 1.004 and the field flatness is within 3.5%. The result of the RF structure design satisfies the physics requirement well. (authors)

[en] Cyclic adenosine 3′-5’-monophosphate (cAMP) plays a crucial role in regulating pituitary cell proliferation and hormone synthesis. Recent evidence suggests that exchange proteins directly activated by cAMP (Epacs) may mediate the effects of cAMP. Here we used rat anterior pituitary GH3 cells as the experiment model to demonstrate that forskolin increased the proliferation of GH3 cells and the phosphorylation of ERK1/2, and these effects were inhibited by PKA or Epac inhibitors. Epac activator 8-pCPT-2′-O-Me-cAMP increased GH3 cell proliferation and this was blocked by ESI-09, an Epac inhibitor. In contrast, forskolin-induced phosphorylation of CREB was unaffected by Epac inhibition. Notably, increased phosphorylation of ERK1/2 was correlated with increased cyclin D3 expression in GH3 cells. Furthermore, knockdown of Epac as well as B-Raf and MEK inhibitors blocked 8-pCPT-2′-O-Me-cAMP induced proliferation of GH3 cells and the phosphorylation of ERK1/2. In conclusion, our study suggests that Epac mediates cAMP induced pituitary cell proliferation via B-Raf and MAPK dependent mechanism. - Highlights: • PKA and Epac mediate cAMP induced GH3 cell proliferation. • Activation or knockdown of Epac stimulates or inhibits GH3 cell proliferation. • Epac induces the phosphorylation of ERK1/2 in GH3 cells via B-Raf. • B-Raf and MEK inhibitors block cAMP induced GH3 cell proliferation.

[en] Objective: To screen radiosensitizing-related genes mediated by elemene in lung adenocarcinoma A549 cells by using gene chip. Methods: MTT test was used to calculate the IC₅₀ of elemene. (1) The effect of radiosensitivity was detected by colony forming assay. A549 cells were divided into 2 groups: radiation group and radiation + elemene group. Oligonucleotide chip was used to screen the gene expression changes of A549 cells from these 2 groups. The up-regulated gene Egr-1 and the down-regulated gene CyclinD1 were selected to undergo RT-PCR so as to confirm the reliability of the result. Results: MTT test showed the elemene inhibited the proliferation of the A549 cells dose-dependently. The IC₅₀ value of elemene on the A549 cells was 120 mg/L. (2) 10 mg/L elemene had radiosensitising effect on A549 cells.The values of SER_D0 and SER_Dq obtained from the survival curve were (1.54±0. 20) and (1.43±0.15) respectively. Gene chip screened 122 differentially-expressed genes, including 89 up-regulated genes and 33 down-regulated genes. (3) These altered genes could be related to cell structure, substance metabolism,cell proliferation, cell differentiation, signal transduction, material transport, DNA repair, apoptosis, immune response and so forth. The RT-PCR results of Egr-1 and Cyclin D1 were consistent with the gene chip analysis. Conclusions: The mechanism of elemene enhancing the radiosensitivity of lung adenocarcinoma A549 cells is the result of participation and collaboration of multiple genes. Further study of the newly-discovered differentially-expressed gene helps find out new radiosensitizational targets of elemene. (authors)

[en] The intense dc beam transport in the solenoid lenses is analyzed with the Lie algebraic method, and the transfer matrix with space charge effects is obtained. Two cases are considered: one of them is that the external focusing force is greater tan the space charge force; another is that the external force is less than the space charge force. The theoretical results are coded and used in the calculations of a low energy beam transport after the ECR ion source. (authors)