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[en] Separate and layered transmitting and receiving spiral coil arrays had been used for the optimized individual applications of magnetostrictive type long-range ultrasonic testing. In this study, it was demonstrated that when taking advantages of the spiral coils with the leg width reduced to be half of the previous one and of the empty spaces due to the decrease of leg width, the transmitting and receiving coil array can be arranged to form a single layer structure allowing more easy use and fabrication. Because of the number of turns of the receiving coils that is proportional to their leg width, the sensitivity of the single layer coil array was about half that of the corresponding double layer coil array while it allowed the receiving amplifier to get faster recovery from a saturation due to the main bang echo. It was also found that the two types of coil arrays have almost the same performances in the view points of signal-to-noise ratio and directivity control.
[en] A new polymorph of PQ-S was demonstrated for the first time. This polymorph was grown in solution through the oxidation of PEN, creating a zigzag structure that was tilted by 21 .deg. with respected to a-axis. The PQ-V crystal had a packing structure similar to a thin-film phase, where oxygen was a critical factor in determining the molecular packing. The remarkable shift in the PL maximum wavelength between PQ-S and PQ-V of up to 30 nm confirmed that the molecular packing difference strongly influenced the light emitting properties. The structural changes from pentacene to pentacenequinone that occured through oxidation were carefully studied in the single crystal analysis and provided useful information on the quality and performance of the pentacene-containing devices. This present study on the polymorph of pentacene and pentacene-quinone provides some basic structural data. Conjugated organic compound thin films have received considerable attention because of their great potentials in thin-film transistors, light emitting diodes and photovoltaic cells. The investigation of organic materials with large charge carrier mobilities has recently become the main research interest in semiconductors. One of the most interesting organic semiconductor materials is pentacene (PEN), which exhibits a remarkably high charge carrier mobility (≥ 1 cm"2V"-"1s"-"1), despite being composed of molecular crystals with a relatively weak van der Waals interaction between the molecules
[en] We searched the medical database to identify the pediatric patients who had visited the ED, and the number of CTs conducted from January 2001 to December 2010. We analyzed the types of CTs, according to the anatomic region, and the patients who underwent CT examinations for multiple regions. Data were stratified, according to the patient age (< 13 years and 13 ≤ ages < 18 years). The number of CTs performed per 1000 patients increased by 92% during the 10-year period (per 1000 patients, increased from 50.1 CTs in 2001 to 156.5 CTs in 2006, and then decreased to 96.0 CTs in 2010). Although head CTs were performed most often (74.6% of all CTs), facial bone CTs showed the largest rate of increase (3188%) per 1000 patients, followed by cervical CTs (642%), abdominal CTs (474%), miscellaneous CTs (236%), chest CTs (89%) and head CTs (39%). The number of patients who had CT examinations for multiple regions in the same day showed a similar pattern of increase, to that of overall CT examinations. Increase of CT utilization was more pronounced in adolescents than in pediatric patients younger than 13 years (189% vs. 59%). The utilization of CTs increases from 2001 to 2006, and has declined since 2006. The increase of CTs is more pronounced in adolescents, and facial bone CTs prevail in increased number of examination followed by cervical CTs, abdominal CTs, miscellaneous CTs, chest CTs, and head CTs.
[en] To retrospectively review findings of osteonecrosis of the femoral head after bone marrow transplantation. We reviewed the clinical and MR findings of osteonecrosis of the femoral head in 23 of 1112 patients who underwent marrow transplantation during a five-year follow-up period lasting from 1996 to 2000. Mean age at the time of diagnosis was 31 (range, 20-47) years, and the mean time from transplant to diagnosis was 17 months. All patients developed variable graft-versus-host disease and seventeen were treated with high-dose prednisolone and/or cysclosporin for severe acute or extensive chronic graft versus host disease. Osteonecrosis was diagnosed by magnetic resonance (MR) imaging, which allowed early detection of disease assessment of its stage. At the time of diagnosis, 15 hips were at stage I, 28 at stage II, two at stage III, and none at stage IV, according to the international ARCO classification system. Osteonecrosis of femoral diaphyses, the lower lumbar spine, or pelvic bones in the MR field was also found to have occurred in 11 patients. Initial treatment was conservative: 21 hips underwent surgery [core decompression (n=10), vascularized fibular bone graft (n=5), and joint replacement (n=6)]. In patients receiving high-dose steroids for the treatment of graft-versus-host disease, MR screening might help detect osteonecrosis at an early stage
[en] We report a case of thymic hyperplasia accompanied by pericardial lipomatosis and right facial hemihypertrophy in an 8-year-old boy. On imaging studies, the hyperplastic thymus had prominent curvilinear and nodular fatty areas simulating a fat-containing anterior mediastinal mass, which is an unusual finding in children. To our knowledge, this is the first report on a child with a combination of thymic hyperplasia, pericardial lipomatosis, and right facial hemihypertrophy. The radiologic findings are presented with a brief discussion.
[en] Giant cavernous malformations are rare. There are 17 cases reported in the literature, eight of them in children. Although cavernous malformations have typical imaging findings, the diagnosis of giant cavernous malformation can be challenging because of its large size and varied appearance. It can be more challenging when imaging reveals multilobular involvement and a focal infiltrative pattern mimicking malignancy. We report a case of a giant cavernous malformation with multilobular involvement and a focal infiltrative pattern. (orig.)
[en] Core-level and valence-band photoemission spectroscopy (PES) measurements have been performed on a Mn12 molecular magnet. Both the C and the O 1s spectra exhibit multiple-peak structures, which reflect the different chemical environments for the different C and O sites in Mn12. The Mn 2p spectrum of Mn12 is very similar to that of La0.7Sr0.3MnO3 (LSMO), suggesting that the valence states of Mn ions in Mn12 are close to those in LSMO. The valence-band spectrum of Mn12 reveals that the Mn 3d states are located near the top of the valence band, which is consistent with the calculated local density of states
[en] Flow diverters are increasingly being used to treat intracranial aneurysms. This study evaluates occurring complications of flow-diverting devices in the treatment of experimental aneurysms, involving the use of micro-CT and small animal MRI at 9.4 T, in correlation to angiographic and histological findings. We previously published two preclinical studies, in which we assessed two different flow diverters in the treatment of elastase-induced aneurysms. Devices have been implanted across the aneurysm neck as well as in the abdominal aorta. From these studies, a total of 65 devices (prototype FD (n = 30) and Derivo embolization device (n = 35)) additionally underwent micro-CT and MRI after angiographic follow-up and before being histologically examined. The different architectures of both devices were precisely comparable due to high-resolution micro-CT imaging. Micro-CT revealed wire fractures in nine cases (30 %) only with the prototype FD. In three cases (10 %), severe wire fractures correlated with an in-stent stenosis due to intimal hyperplasia. Other complications, like distal stent occlusions and post-stent stenosis, were seen in both groups and verified with both imaging techniques. Osseous metaplasia were correlated to calcifications seen with micro-CT. MRI enabled visualization of the position of the implanted devices relative to the aneurysm and revealed incomplete aneurysm neck coverage with the prototype FD in two cases (6.7 %). Micro-CT and 9.4-T MRI are valid to discover and understand occurring complications of flow diverters in the preclinical phase and can serve as evaluation tools to minimize complication rates of endovascular devices in the future. (orig.)
[en] The objective of the study was to validate an adaptive, contrast-oriented thresholding algorithm (COA) for tumour delineation in 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) for non-small cell lung cancer (NSCLC) in comparison with pathological findings. The impact of tumour localization, tumour size and uptake heterogeneity on PET delineation results was also investigated. PET tumour delineation by COA was compared with both CT delineation and pathological findings in 15 patients to investigate its validity. Correlations between anatomical volume, metabolic volume and the pathology reference as well as between the corresponding maximal diameters were determined. Differences between PET delineations and pathological results were investigated with respect to tumour localization and uptake heterogeneity. The delineated volumes and maximal diameters measured on PET and CT images significantly correlated with the pathology reference (both r > 0.95, p < 0.0001). Both PET and CT contours resulted in overestimation of the pathological volume (PET 32.5 ± 26.5 %, CT 46.6 ± 27.4 %). CT volumes were larger than those delineated on PET images (CT 60.6 ± 86.3 ml, PET 48.3 ± 61.7 ml). Maximal tumour diameters were similar for PET and CT (51.4 ± 19.8 mm for CT versus 53.4 ± 19.1 mm for PET), slightly overestimating the pathological reference (mean difference CT 4.3 ± 3.2 mm, PET 6.2 ± 5.1 mm). PET volumes of lung tumours located in the lower lobe were significantly different from those determined from pathology (p = 0.037), whereas no significant differences were observed for tumours located in the upper lobe (p = 0.066). Only minor correlation was found between pathological tumour size and PET heterogeneity (r = -0.24). PET tumour delineation by COA showed a good correlation with pathological findings. Tumour localization had an influence on PET delineation results. The impact of tracer uptake heterogeneity on PET delineation should be considered carefully and individually in each patient. Altogether, PET tumour delineation by COA for NSCLC patients is feasible and reliable with the potential for routine clinical application. (orig.)
[en] Highlights: •TrkA was mainly present in other types of leukemia including AML. •TrkA enhances the survival of leukemia by activation of PI3K/Akt pathway. •TrkA induced significant hematological malignancies by inducing PLK-1 and Twist-1. •TrkA acted as a key regulator of leukemogenesis and survival through c-Src activation. -- Abstract: Although the kinase receptor TrkA may play an important role in acute myeloid leukemia (AML), its involvement in other types of leukemia has not been reported. Furthermore, how it contributes to leukemogenesis is unknown. Here, we describe a molecular network that is important for TrkA function in leukemogenesis. We found that TrkA is frequently overexpressed in other types of leukemia such as acute lymphoblastic leukemia (ALL), chronic myelogenous leukemia (CML), and myelodysplastic syndrome (MDS) including AML. In addition, TrkA was overexpressed in patients with MDS or secondary AML evolving from MDS. TrkA induced significant hematological malignancies by inducing PLK-1 and Twist-1, and enhanced survival and proliferation of leukemia, which was correlated with activation of the phosphatidylinositol 3-kinase/Akt/mTOR pathway. Moreover, endogenous TrkA associated with c-Src complexes was detected in leukemia. Suppression of c-Src activation by TrkA resulted in markedly decreased expression of PLK-1 and Twist-1 via suppressed activation of Akt/mTOR cascades. These data suggest that TrkA plays a key role in leukemogenesis and reveal an unexpected physiological role for TrkA in the pathogenesis of leukemia. These data have important implications for understanding various hematological malignancies