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This paper shows the verification work of SARAX code system in the reactor core transient calculation based on the simplified EBR-II Benchmark. The SARAX code system is an analysis package developed by Xi'an Jiaotong University and aims at the advanced reactor R&D. In this work, a neutron-photon coupled power calculation model and a spatial-dependent reactivity feedback model were introduced. To verify the models used in SARAX, the EBR-II SHRT-45R test was simplified to an ULOF transient with an input flowrate change curve by fitting from reference. With the neutron-photon coupled power calculation model, SARAX gave close results in both power fraction and peak power prediction to the reference results. The location of the hottest assembly from SARAX and reference are the same and the relative power deviation of the hottest assembly is 2.6%. As for transient analysis, compared with experimental results and other calculated results, SARAX presents coincident results both in trend and absolute value. The minimum value of core net reactivity during the transient agreed well with the reported results, which ranged from −0.3$ to −0.35$. The results verify the models in SARAX, which are correct and able to simulate the in-core transient with reliable accuracy.

Rationale and Objectives To demonstrate the improved enhancement degree and uniformity in coronary CT angiography (CCTA) on a 16 cm wide-coverage CT with a new bolus tracking method enabled by free-breathing, in comparison with the conventional breath-holding method. Materials and Methods A total of 200 patients with suspected coronary heart disease were randomly divided into two groups for CCTA: Group A (n = 100, free-breathing) started CCTA with 2.2 seconds delay after the attenuation in aorta reached 250 HU; Group B (n = 100, breath-holding), used the standard protocol of 80 HU threshold and 8.4 seconds delay. Both groups used the contrast dose rate of 25 mgI/kg/s. CT value and standard deviation in aortic sinus (AS), right coronary artery, left anterior descending, left circumflex, and pericardial fat were measured. Contrast-to-noise ratio for vessels was calculated. Two experienced Radiologists independently reviewed image quality using a 5-point scale (1: nondiagnostic—5: excellent). Results There was no difference in contrast dose, radiation dose, heart rate, and qualitative image quality between the two groups (all p > 0.05). However, Group A had higher mean enhancement in vessels (404 ± 66 HU) than Group B (321 ± 69 HU), and lower coefficients of variation of CT value in aortic sinus, right coronary artery, left anterior descending, and left circumflex (16.3%, 17.7%, 19.2%, and 20.5% vs 21.5%, 22.3%, 23.6%, and 22.9%, respectively), (all p Conclusion A new bolus tracking method enabled by free-breathing in CCTA on a 16 cm wide-coverage CT system increases the enhancement degree and uniformity in coronary arteries, compared with the conventional breath-holding method.

Zheng Li, Xiaoqian Jia, Xiaoling Peng, Feng Gao Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People’s Republic of ChinaCorrespondence: Feng GaoDepartment of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Ave, Wuhan 430030, People’s Republic of ChinaEmail fgao@tjh.tjmu.edu.cnPurpose: Opioid tolerance remains a challenging problem, which limits prolonged drug usage in clinics. Previous studies have shown a fundamental role of platelet-derived growth factor receptor β submit (PDGFRβ) in morphine tolerance. The aim of this study was to investigate the mechanisms of spinal PDGFRβ activation in morphine tolerance.Methods: Rats were treated with morphine for 7 days and the effect of drug was evaluated by tail-flick latency test. By using Western blot and real-time PCR, the interaction between μ opioid receptor (MOR) and PDGFRβ in microglia activation, as well as related signaling pathways during morphine tolerance were investigated.Results: Chronic PDGFRβ agonist could induce microglia activation in spinal cord and decrease the analgesic effect of morphine. PDGFRβ inhibitor suppressed microglia activation during the development of morphine tolerance. Furthermore, antagonizing MOR could effectively inhibit the phosphorylations of PDGFRβ and JNK. Blocking PDGFRβ had no influence on JNK signaling, while JNK inhibitor could decrease the phosphorylation of PDGFRβ.Conclusion: These results provide direct evidence that repeatedly activating MOR by morphine could induce the transactivation of PDGFRβ via JNK MAPK in spinal cord, which leads to microglia activation during the development of morphine tolerance.Keywords: mu opioid receptor, platelet-derived growth factor receptor β, microglia, JNK signaling, morphine tolerance

Investigate the clinical value of improving diagnostic accuracy for arteries of lower extremities with low energy images in dual-energy spectral CT (DEsCT) imaging.110 (mean age, 67 ± 10 years) and 72 (mean age, 65 ± 13 years) patients underwent CT angiography (CTA) in the lower extremities using dual-energy and conventional (100kVp) imaging mode, retrospectively. The 50 keV monochromatic images were reconstructed in the DEsCT group for analysis. The quantitative and qualitative image quality of the two groups were compared using various statistical analysis methods and the diagnostic accuracy for the degree of vessel stenosis was compared using DSA as the gold standard. Consistency test was used for intra-group evaluation. A P 0.05 was considered statistically significant.The use of 50 keV images in DEsCT significantly increased the enhancement in arteries of LKS (544.91 ± 106.37HU vs. 339.65 ± 83.74HU, P 0.001) and provided higher SNR (19.92±9.39 vs. 17.39±4.99, P = 0.04) and CNR (45.60±16.61 vs. 38.70±18.17, P 0.01) compared with conventional 100kVp images. Mann-Whitney test showed that the subjective image quality of the arteries of lower knee segment (LKS) in the DEsCT group was higher than in the conventional group (P = 0.01). The diagnostic efficiency of DEsCT group was better than that of conventional group, mainly in arteries of LKS (95.91 % vs. 87.85 %, for 50 % stenosis, P0.001; 94.32 % vs. 89.58 % for occlusion, P = 0.02).The use of 50 keV DEsCT images enhances the contrast in the lower extremity arteries and improves the diagnostic accuracy for the arteries of LKS, compared with the conventional CTA protocols.

To compare image quality, radiation, and contrast medium (CM) doses between individualized and conventional scan protocols in combined coronary CT angiography (CCTA) and iliac artery CTA for kidney transplantation patients.148 patients needing assessment for coronary and iliac arteries before kidney transplantation were prospectively enrolled and randomly divided into the conventional and individualized groups. All patients underwent one-stop combined scans on a 256-row CT scanner with automatic tube current modulation, 50 % pre-ASIR-V to control radiation dose. CCTA was performed first using one heartbeat axial scan mode with bolus tracking technique and iliac CTA was performed 3 s after CCTA using a spiral scan. The conventional group (n = 72) used the standard protocol: 100 kVp, 60 mL of 350 mgI/mL CM at 4.5 mL/s flow rate. The individualized group (n = 76) used a body-mass-index (BMI)-dependent protocol: kVp: 80 (BMI 24) and 100 (BMI ≥ 24) and CM: 19 mgI/kg (BMI 18); 21 mgI/kg (18 ≤ BMI 24); and 22 mgI/kg (BMI ≥ 24). Image quality radiation and CM doses of the two groups were compared.There was no significant difference in patient demographic data. Compared with the conventional group, the individualized group reduced contrast flow rate (in mL/s) by 14.4 % (3.85 ± 0.72 vs. 4.5), contrast dose (in mL) by 35.8 % (38.53 ± 7.18 vs. 60) and radiation dose (in mSv) by 34.3 % (4.30 ± 1.73 vs. 6.54 ± 1.45). The individualized group had significantly higher subjective image quality score (P ＜ 0.05), lower noise (17.30 ± 4.97 HU vs. 19.13 ± 4.73 HU, P = 0.02) and higher signal-to-noise ratio (22.09 ± 7.41 vs. 19.55 ± 6.18, P = 0.03) for the three main vessels in CCTA compared with the conventional group. There were no differences in both subjective scores and objective measurements in iliac artery CTA between the two groups.The individualized scanning protocol in the one-stop assessment of coronary and iliac arteries before kidney transplantation significantly reduces both radiation and CM doses while maintaining image quality in iliac artery CTA and providing better coronary artery images in CCTA.