[en] A partitioned fluid-structure interaction (FSI) solving strategy that depends on problem characteristics is applied to quantitatively obtain the coupling effects of a fluid-structure system in a single-blade centrifugal pump on the unsteady flow. A two-way coupling method is employed to realize strong FSI effects in the calculation procedure. The successful impeller oscillation measurement using two proximity sensors validated the FSI simulation accuracy in a complicated and practical fluid-structure system having a rotating component. The results show that the hydrodynamic force deviation can be observed in the results for the coupled versus uncoupled cases. Additionally, the coupled unsteady pressure is larger than the uncoupled value for every monitoring point at every impeller rotation position. Comparison results for different monitoring points under an overload condition and partial-load condition display the same regularities. To some extent, this interaction mechanism would affect the accuracy and reliability of the unsteady flow and rotor deflection analysis.

[en] Objective: To evaluate the microscopic characteristics of hepatocellular carcinoma (HCC) invasion, and to provide the reference for GTV-to-CTV expansion. Methods: From January 2002 to January 2006, 149 HCC patients treated by surgical resection were included. The pathologic slices and clinical data were reviewed, including the tumor size, capsule status, tumor edge, portal vein invasion, TNM stage, histology grade, serum alpha-fetoprotein (AFP), platelet count and the degree of liver cirrhosis. The distance between the tumor capsule and the-invasion was measured by 2 senior pathologists. Results: Of the 149 patients evaluated, 79 (53.0%) patients presented micro-invasion ranged between 0.5-4.0 mm. The recurrence rate was higher in patients with micro-invasion than those without (44% vs 29%, P=0.047). The invasion extent was positively relative to the tumor size, capsule status, tumor edge, portal vein invasion, TNM stage, histology grade and AFP, while negatively relative to the platelet count. A score system was established according to five predictors of tumor size, capsule status, portal vein invasion, AFP and platelet count. The invasion distance below 2 mm was in 96.6% patients who had ≤2 points and only 83.3% for those with > 2 points. Conclusions: For HCC patients, the invasion extent is relative to the tumor size, capsule status, portal vein invasion, AFP and platelet count. These 5 predictors could be potentially used as a score system for GTV-to-CTV expansion. (authors)

[en] Perovskite oxides BaCe_1-xEu_xO_3-δ (x = 0.05, 0.10, 0.15, and 0.20) were prepared using starting ratios of Ba/(Ce + Eu) = 1.0 and 1.1. X-ray diffraction analysis shows that preparations with a slight initial barium excess crystallized as a single perovskite phase, while the stoichiometric preparations crystallized with a trace of CeO₂ due to Ba loss. EPR measurements indicate that the samples have no Ba vacancies and that Eu and Ce ions are in trivalent and tetravalent states, respectively. The single-phase samples synthesized from Ba/(Ce + Eu) = 1.1 preparations are shown to have different cell volume trends versus x, lower average thermal expansion coefficients, and higher proton conductivities in water-containing atmospheres between 80 and 700 deg. C, compared to samples synthesized from the Ba/(Ce + Eu) = 1.0 preparations. These observations are explained in terms of the impurity CeO₂ phase, Eu doping-site preferences, and oxygen vacancy generation

[en] Objective: To investigate the value of MR perfusion parameters and ADC in the diagnosis of pancreatic cancer and pancreatic mass at 3.0 T MR. Methods: Twenty healthy volunteers and 25 patients with pancreatic cancers proven by pathological results underwent MR PWI at a 3.0 T scanner. A two-compartment model was used to quantify K^trans, K_ep and V_e in the pancreatic cancer, adjacent pancreatic tissue, distal inflammatory pancreatic tissue and normal pancreatic tissue. All parameters among different tissues were analyzed and compared with ANONA. Fifteen normal volunteers and 58 patients, including 30 patients with pancreatic cancer (proven histopathologically), 9 patients with pancreatitis pseudotumor (4 patients proven by histopathological results, 5 patients proven by follow-up after treatment), 9 patients with solid pseudopapillary tumor of pancreas (SPTP, proven histopathologically) and 10 patients with pancreatic neuroendocrine tumor (PET, proven by histopathology), underwent respiratory-triggered DWI on 3.0 T. ADC values of normal pancreas and all types of pancreatic lesions were statistically analyzed and compared with ANONA. ROC curve was used to analyze the diagnostic power of ADC value. Results: K^trans of pancreatic cancer, adjacent pancreatic tissue, distal inflammatory pancreatic tissue and normal pancreatic tissue were (1.66±1.25), (3.77±2.67), (1.16±0.94) and (2.69±1.46 )/min respectively (F= 8. 160, P <0.. 01). LSD test showed t.hat I(tans in the pancreatic cancer was statistically lower than that in normal pancreas (P=0.011) and adjacent pancreatic tissue (P=0.002). K_ep of pancreatic cancer, adjacent pancreatic tissue, distal inflammatory pancreatic tissue and normal pancreatic tissue were (2. 53 +1. 55) , (5.64±2.64), (1.70±0.91) and (4.28±1.64)/min respectively (F=4.544, P<0.01). LSD test revealed that K_ep in pancreatic cancer was statistically lower than that in normal pancreatic tissue (P= 0.035) and adjacent pancreatic tissue (P=0.041). The median of V_e among the pancreatic cancer, adjacent pancreatic tissue, distal inflammatory pancreatic tissue and normal pancreatic tissue were 0.926, 0.839, 0.798 and 0.659 respectively (χ² =12.040, P<0.01). V_e in pancreatic cancer was statistically higher than that in normal pancreatic tissue (P=0.002). ADC values of the pancreatic cancer, pancreatitis pseudotumor, SPTP, PET and normal pancreas were (1.57±0.26) ×10^-3, (1.19±0.15)×10^-3 (1.05±0.35)×10^-3, (1.62±0.41)×10^-3 and (1.82±0.25)×10^-3 mm²/s (F=21.681, P<0.01). LSD test showed there were significant statistical differences in ADC values among pancreatic cancer, pancreatitis pseudotumor and normal pancreatic tissue (P<0.01). ROC curve disclosed that the sensitivity, specificity, positive predictive value and negative predictive value were 86.7%, 88.9%, 96.3% and 66.7% respectively, when ADC ≥ 1.33×10^-3 mm²/s was used as a cutoff value for differential diagnosis of PDCA from MLP. The sensitivity, specificity, positive predictive value and negative predictive value were 77.8% , 100.0%, 100.0% and 83.3% respectively when ADC ≤ 1.25×10^-3 mm²/s was used as a cutoff value for differential diagnosis of SPTP from PET. Conclusion: Compared to normal pancreatic tissue, pancreatic cancer usually had a lower K^trans, K_ep and larger V_e. ADC values from respiratory-triggered DWI were well related to histopathological features of pancreatic entities and may be helpful in the differential diagnosis. (authors)

[en] The thin target M-shell X-ray production cross sections have been measured for Ta, Au and Bi with impact over the energy from 0.6 to 2.75 MeV. The measured cross sections are compared with the plane wave Born approximation (PWBA) theory

[en] A suspended-thin-sample (STS) approach for signal selection and contrast separation is developed in scanning electron microscopes with commonly used primary beam energies and traditional detectors. Topography contrast, electron channeling contrast and composition contrast are separated and largely enhanced from suspended thin samples of several hundred nanometers in thickness, which is less than the escape depth of backscattered electrons. This imaging technique enables to detect relatively pure secondary electron and elastic backscattered electron singles, whereas suppress multiple inelastic scattering effects. The provided contrast features are different from those of bulk samples, which are largely mixed with inelastic scattering effects. The STS imaging concept and method could be expected to have more applications in distinguishing materials of nanostructures, multilayers, compounds and composites, as well as in SEM-based electron backscatter diffraction, cathodoluminesence, and x-ray microanalysis. - Highlights: ●We developed a suspended-thin-sample (STS) method for contrast separation in the SEM. ●The STS method greatly enhances electron channeling contrast and composition contrast. ●Contrast separating was achieved by commonly utilized beam energies and detectors. ●The STS method provides higher resolution and much lower image noise

[en] Objective: To explore the imaging features of primary malignant fibrous histiocytoma (MFH) of bone and correlate them with pathological findings. Methods: Thirteen cases patients with primary MFH of bone confirmed by surgical pathology underwent radiography, spiral CT plain scanning and MR SE-T_WI, T₂WI and SE-T₁WI enhancement scanning before operation. The imaging date was reviewed and analysed retrospectively in comparison with surgical and pathological results. Results: Of 13 MFH, 11 were located in the end of long bone, and 2 in the diaphysis. The distance between tumors in the end of long bone and adjacent joint surface was 1 to 5 cm. All lesions showed osteolytic destruction with the maximum diameter of the tumors from 5.3 to 12.7 cm. The tumors had eccentric aggressive osteolytic destruction in 10 lesions, internal crest within the lesions in 7, inconsecutive marginal osteosclerosis in 11, little periosteal reaction in 2 and small soft tissue masses in 9, respectively. The CT value of lesions was similar to muscle. MR imaging depicted low signal intensity with aggressive features on T₁WI, iso to slight high signal intensity on T₂WI, and middle or high degree contrast enhancement on enhanced T₁WI images. Macroscopically, MFH was usually located eccentrically within the bone and produced little or no osseous expansion. The soft tissue component appeared multi-nodules and pseudo-encapsulated. Histologically, they consisted of spindle-shaped fibroblasts, which radiated outward in a spiral array from a central focus and produced a nebula or storiform appearance, and cells, which were small and oval with little visible cytoplasm. Conclusions: The imaging manifestations of MFH were specific to some extent. Combined utilization of plain X-ray, CT, and MRI is helpful for the diagnosis and differential diagnosis of MFH. (authors)

[en] Objective: To explore and evaluate MRI in diagnosing primary muscle non-Hodgkin lymphoma. Methods: Six surgically confirmed primary muscle non-Hodgkin lymphoma underwent MR examination including T₁WI, T₂WI and T₁WI enhanced studies. The acquired images date was reviewed and analysed retrospectively in comparison with surgical and pathological results. Results: The locations of 6 cases were cervical part (2), upper extremity (1), lower extremity (3), respectively. All cases involved of more than one anatomical compartment with poorly defined solid masses in 5 cases and well defined in 1 cases, 5 extended to subcutaneous fat and 3 extended along the neurovascular bundle. The mean tumor diameter was 13.9 cm, ranging from 7.3 to 22.5 cm. One was well demarcated and 5 were ill-defined. On T₁WI, 2 were slightly high signal intensity and 4 were slightly low signal intensity. On T₂WI, 2 were slightly high signal intensity, 3 were intermediate signal intensity and 1 was high signal intensity. Five were inhomogeneous and 1 was homogeneous. The intrinsic structure such as muscle fiber, tendo, spatium intramuscular were detected on 5 cases. Of the 5 dynamic contrast-enhanced cases, it showed moderate enhancement during arterial phase, 2 were homogeneous and 3 were inhomogeneous. And it showed progressive enhancement during interstitial phase, 3 were homogeneous and 2 were inhomogeneous. Conclusions: Primary muscle lymphoma always originated deep to the fascia showing subcutaneous extension and multiple compartment invasion. Typically from poorly defined solid masses with slightly high in signal intensity on MR T₂WI and middle degree dynamic delayed contrasted-enhanced in which intrinsic anatomic structure such as muscle fiber, tendo, spatium intramuscular and so on can be discerned, almost all cases involve more than one muscle compartment and some of tumor extend along the neurovascular bundle. (authors)

[en] Objective: To Explore the imaging features relative to pathology of pelvic chondrosarcoma and to evaluate the clinical value. Methods: All 12 cases patients with primary pelvic chondrosarcoma confirmed by pathological examination underwent radiography, spiral CT plain scanning, MR SE-T₁WI, FSE-T₂WI and SE-T₁WI enhancement scanning before operation. The imaging data was reviewed and analyzed retrospectively to compare with surgical and pathological results. Results: Eleven conventional chondrosarcoma and one dedifferentiated chondrosarcoma were located in different parts of pelvis. The diameters of the tumors ranged from 4.7 to 17.0 cm with one case less than 5.0 cm, 6 cases being 5.0-10.0 cm and 5 cases more than 10.0 cm. The CT value of 5 eases was identical or inferior to muscle with mild to moderate 'ring-and-arc' mineralization and soft mass. MR imaging depict the high water content of these lesions as very high signal intensity was detected on T₂WI. Six cases showed typical 'ting- and-arc' fibrous tissue which enhanced persistently. Aggressive features of deep endosteal scalloping and soft-tissue extension was also found in these cases. Conclusions: Radiographic findings can suggest the diagnosis of pelvic chondrosarcoma when there is typical 'ring-and-arc' fibrous tissue, mineralization, aggressive features of deep endosteal scalloping and large soft-tissue extension. MR imaging reflect directly this pathologic structure, superior to that of CT and radiography. CT is optimal to detect the matrix mineralization, particularly when it is subtle or when the lesion is located in anatomically complex pelvic areas. (authors)

[en] Objective: To investigate the CT and MRI findings of primary hepatic neuroendocrine carcinomas. Methods: Imaging findings of 6 patients with pathologically confirmed hepatic neuroendocrine carcinomas were retrospectively analyzed. Four patients underwent plain CT and contrast enhanced CT examinations. The other 2 patients underwent plain MRI and contrast enhanced MRI. Results: One out of the 6 eases manifested multicentric tumor which appeared as one large tumor surrounded with multiple small nodules peripherally, and the tumors of the other 5 cases were solitary. On plain CT images, all lesions were well-defined and hypoattenuating with central areas of even lower density except punctuate calcifications at tumor periphery in 1 case. On pre-contrast MRI, the cases manifested heterogeneous low signal intensity on T₁WI and slightly high intensity on T₂WI. On dynamic contrast enhanced CT and MRI, Tumors manifested slight to mild enhancement in arterial phase, slight enhancement in portal venous phase or delayed phase with no enhancement in the center, accompanied by dislocation of surrounding vessels. There was no lymphadenopathy in peritoneal cavity and retroperitonium. Conclusion: CT and MRI scanning can demonstrate specific features of primary hepatic neuroendocrine carcinoma, which may help the diagnosis and differential diagnosis of the tumor. (authors)