Activation and shutdown dose-rate analyses for the EAST NBI test facility

An analysis of the neutron activation and shutdown dose rates was performed for the EAST high-power deuterium neutral beam injector test facility(EAST NBITF) by using the multiparticle transport code FLUKA2011.2. Also, the neutron and neutron-induced gamma spectra of the facility's vacuum vessel were evaluated. The results identified the major radionuclides^(99) Mo,^(65)Ni,^(58) Co,^(56)Mn, and^(51) Cr for the vacuum vessel and the primary nuclide^(64) Cu for both the ion dump and the calorimeter.The simulated results indicated that, when the EAST NBITF operates within the design parameters of deuterium energy 80 ke V, current 50 A, and pulse 100 s, the neutron intensity will achieve 10^(11)n/s with no radiation safety problems after the EAST NBITF shuts down.

Undifferentiated high-grade pleomorphic sarcoma of the common bile duct:A case report and review of literature

BACKGROUND Undifferentiated pleomorphic sarcoma(UPS)is a rare malignant mesenchymal tumor with a poor prognosis.It mainly occurs in the extremities,trunk,head and neck,and retroperitoneum regions.Owing to the lack of specific clinical manifestations and imaging features,UPS diagnosis mainly depends on pathological and immunohistochemical examinations for exclusive diagnosis.Here we report an extremely rare case of high-grade UPS in the common bile duct(CBD).There are limited available data on such cases.CASE SUMMARY A 70-year-old woman was admitted to our department with yellow eyes and urine accompanied by upper abdominal distending pain for 2 wk.Her laboratory data suggested significantly elevated hepatorenal function levels.The imaging data revealed calculous cholecystitis,intrahepatic and extrahepatic bile duct dilation with extrahepatic bile duct calculi,and a space-occupying lesion at the distal CBD.After endoscopic biliary stenting and symptomatic support therapy,CBD exploration and biopsy were performed.The frozen section indicated malignant spindle cell tumor of the CBD mass,and further radical pancreaticoduodenectomy was performed.Finally,the neoplasm was diagnosed as a high-grade UPS combined with the light-microscopic morphology and immunohistochemical results.CONCLUSION This extremely rare case highlighted the need for increasing physicians'vigilance,reducing the odds of misdiagnosis,and providing appropriate treatment strategies.

Thermodynamic analysis and simulation for gas baffle entrance collimator of EAST-NBI system based on thermo-fluid coupled method

The world's first full Experimental Advanced Superconducting Tokamak(EAST) is designed with the auxiliary heating method of neutral beam injection(NBI)system. Beam collimators are arranged on both sides of the beam channel for absorbing the divergence beam during the beam transmission process in the EAST-NBI system.The gas baffle entrance collimator(GBEC) is a typical high-heat-flux component located at the entrance of gas baffle. An efficient and accurate analysis of its thermodynamic performance is of great significance to explore the working limit and to ensure safe operation of the system under a high-parameter steady-state condition. Based on the thermo-fluid coupled method, thermodynamic analysis and simulation of GBEC is performed to get the working states and corresponding operating limits at different beam extraction conditions. This study provides a theoretical guidance for the next step to achieve long pulse with highpower experimental operation and has an important reference to ensure the safe operation of the system.

Anastomosing hemangioma arising from the left renal vein:A case report

BACKGROUND Anastomosing hemangioma(AH)is a rare subtype of benign hemangioma that is most commonly found in the genitourinary tract.Due to the lack of specific clinical and radiologic manifestations,it is easily misdiagnosed preoperatively.Here,we report a case of AH arising from the left renal vein that was discovered incidentally and confirmed pathologically,and then describe its imaging characteristics from a radiologic point of view and review its clinicopathologic features and treatment.CASE SUMMARY A 74-year-old woman was admitted to our department for a left retroperitoneal neoplasm measuring 2.6 cm×2.0 cm.Her laboratory data showed no significant abnormalities.A non-contrast-enhanced computed tomography(CT)scan showed a heterogeneous density in the neoplasm.Non-contrast-enhanced magnetic resonance imaging(MRI)revealed a heterogeneous hypointensity on T1-weighed images and a heterogeneous hyperintensity on T2-weighed images.On contrastenhanced CT and MRI scans,the neoplasm presented marked septal enhancement in the arterial phase and persistent enhancement in the portal phase,and its boundary with the left renal vein was ill-defined.Based on these clinical and radiological manifestations,the neoplasm was initially considered to be a neurogenic neoplasm in the left retroperitoneum.Finally,the neoplasm was completely resected and pathologically diagnosed as AH.CONCLUSION AH is an uncommon benign hemangioma.Preoperative misdiagnoses are common not only because of a lack of specific clinical and radiologic manifestations but also because clinicians lack vigilance and diagnostic experience in identifying AH.AH is not exclusive to the urogenital parenchyma.We report the first case of this neoplasm in the left renal vein.Recognition of this entity in the left renal vein can be helpful in its diagnosis and distinction from other neoplasms.

Radiological aspects of giant hepatocellular adenoma of the left liver: A case report

BACKGROUND Hepatocellular adenoma(HCA)is very rare and has a high misdiagnosis rate through clinical and imaging examinations.We report a case of giant HCA of the left liver in a young woman that was diagnosed by medical imaging and pathology.CASE SUMMARY A 21-year-old woman was admitted to our department for a giant hepatic tumor measuring 22 cm×20 cm×10 cm that completely replaced the left hepatic lobe.Her laboratory data only suggested mildly elevated liver function parameters and C-reactive protein levels.A computed tomography(CT)scan showed mixed density in the tumor.Magnetic resonance imaging(MRI)of the tumor revealed a heterogeneous hypointensity on T1-weighed MR images and heterogeneous hyperintensity on T2-weighed MR images.On dynamic contrast CT and MRI scans,the tumor presented marked enhancement and the subcapsular feeding arteries were clearly visible in the arterial phase,with persistent enhancement in the portal and delayed phases.Moreover,the tumor capsule was especially prominent on T1-weighted MR images and showed marked enhancement in the delayed phase.Based on these imaging manifestations,the tumor was initially considered to be an HCA.Subsequently,the tumor was completely resected and pathologically diagnosed as an HCA.CONCLUSION HCA is an extremely rare hepatic tumor.Preoperative misdiagnoses were common not only due to the absence of special clinical manifestations and laboratory examination findings,but also due to the clinicians’lack of practical diagnostic experience and vigilance in identifying HCA on medical images.Our case highlights the importance of the combination of contrast-enhanced CT and MRI in the preoperative diagnosis of HCA.