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991.
992.
BACKGROUND: Noncutaneous psammomatous melanotic schwannoma has recently been reported as an unusual component of Carney's complex (myxomas, spotty pigmentation, and endocrinopathy). The most common locations for this lesion include peripheral nerve roots and the gastrointestinal tract. OBSERVATIONS: A cutaneous psammomatous melanotic schwannoma is reported in a patient with known Carney's complex. This neoplasm was pseudoencapsulated, with epithelioid to spindle-shaped cells and no nuclear atypia. Immunostaining was positive for S100 protein and vimentin, as well for HMB-45 antibody. Electron microscopy showed melanosomes in cytoplasmic processes of cells that were ensheathed by layers of reduplicated basal lamina. CONCLUSIONS: Location in the superficial soft tissues is extremely unusual for psammomatous melanotic schwannomas. Recognition of this new cutaneous marker as a part of this complex may aid in identification of individuals at risk for cardiac myxomas. It is also important that this lesion is not mistaken for melanoma, given the strong HMB-45 positivity. 相似文献
993.
Aki Sorsa Ari Isokangas Suvi Santa-aho Minnamari Vippola Toivo Lepistö Kauko Leiviskä 《Journal of Nondestructive Evaluation》2014,33(1):43-50
Residual stresses are quantitatively predicted based on the Barkhausen noise measurement with a partial least squares regression model. The measurements are taken from two sets of case-hardened samples. The benefits of using certain feature elimination strategies prior model identification are also studied. The elimination methods applied are correlation-based elimination, uninformative variable elimination and successive projections algorithm. The results show that the best predictions are usually obtained when the successive projections algorithm is applied. The prediction accuracy of the best models found shows that partial least squares models can be successfully used for prediction of material properties based on the Barkhausen noise measurement. 相似文献
994.
Paxton Juuti Anssi Arffman Antti Rostedt Juha Harra Jyrki M. Mäkelä Jorma Keskinen 《Aerosol science and technology》2016,50(5):487-496
A new instrument, density monitor (DENSMO), for aerosol particle size distribution characterization and monitoring has been developed. DENSMO is operationally simple and capable of measuring the effective density as well as the aerodynamic and the mobility median diameters with a time resolution of 1 s, from unimodal particle size distributions. The characterization is performed with a zeroth order mobility analyzer in series with a low pressure impactor and a filter stage. The operation of DENSMO was investigated with sensitivity analysis and, based on the results, optimal operation parameters were determined. DENSMO was also compared, in lab test measurements, against a reference method with several particle materials with bulk densities from 0.92 to 10.5 g/cm3. The results show that the deviation from the reference method was less than 25% for suitable materials.
Copyright © 2016 American Association for Aerosol Research 相似文献
995.
Lipids and phytosterol oxidation products in commercial potato crisps commonly consumed in Sweden 总被引:1,自引:0,他引:1
Elham Tabee Margaretha Jägerstad Paresh C. Dutta 《European Food Research and Technology》2008,227(3):745-755
The stability of frying oils and fried foods is mainly affected by the fatty acids present and by the types and levels of
minor components such as phytosterols and tocopherols. This study assessed the current status of lipid composition and the
occurrence of oxidised phytosterols as a parameter of lipid oxidation in potato crisps available in the Swedish market. Fatty
acid composition and concentrations of tocopherols, sterols and phytosterol oxidation products (POPs) were determined in 16
commercial potato crisp samples of two types, distinguished by a high or low fat content. The fatty acid composition in most
samples was dominated by saturated and monounsaturated fatty acids. The sum of α-tocopherol and γ-tocopherol content varied
from undetectable levels to 10.2 mg/100 g potato crisps, with α-tocopherol dominating. Among the tocotrienols, α-tocotrienol
and γ-tocotrienol were present in almost equal proportions, while δ-tocotrienol was present in all samples but in smaller
amounts. Fatty acid composition, tocopherol and tocotrienol content, showed that all potato crisp samples were prepared in
palm oil or a blend of palm oil and unspecified fats and oils. Total sterol content ranged from 10.2 to 93.1 mg/100 g sample,
with β-sitosterol being the major sterol in all samples. The content of POPs ranged from 0.05 to 0.68 mg/100 g potato crisps.
In general, there were no significant differences in content of POPs between high and low fat samples, and generally no correlations
could be established between content of POPs and fatty acid, tocopherol, tocotrienol, and sterol content among the potato
crisp samples. 相似文献
996.
Y Yang SE Raper JA Cohn JF Engelhardt JM Wilson 《Canadian Metallurgical Quarterly》1993,90(10):4601-4605
Cystic fibrosis (CF) is an inherited disease of epithelial cell ion transport that is associated with pathology in multiple organ systems, including lung, pancreas, and liver. As treatment of the pulmonary manifestations of CF has improved, management of CF liver disease has become increasingly important in adult patients. This report describes an approach for treating CF liver disease by somatic gene transfer. In situ hybridization and immunocytochemistry analysis of rat liver sections indicated that the endogenous CFTR (cystic fibrosis transmembrane conductance regulator) gene is primarily expressed in the intrahepatic biliary epithelial cells. To specifically target recombinant genes to the biliary epithelium in vivo, recombinant adenoviruses expressing lacZ or human CFTR were infused retrograde into the biliary tract through the common bile duct. Conditions were established for achieving recombinant gene expression in virtually all cells of the intrahepatic bile ducts in vivo. Expression persisted in the smaller bile ducts for the duration of the experiment, which was 21 days. These studies suggest that it may be feasible to prevent CF liver disease by genetically reconstituting CFTR expression in the biliary tract, using an approach that is clinically feasible. 相似文献
997.
B Kruslin S Juki? Z Delija-Prese?ki G Simi? M Kos T Tkalcevi? 《Canadian Metallurgical Quarterly》1996,118(7-8):152-154
We have analyzed all available data including birth certificates, maternity records, pediatric records, and pathology reports of spontaneous and induced abortions and newborn deaths to determine the frequency of congenital anomalies of the central nervous system. We found 76 infants (34 males, 39 females and 3 of undetermined sex) with CNS anomalies during the 1990-93 period. In the same period there were 23,425 births. The frequency of CNS anomalies in this period was 32,4/10,000 births. These results are at variance with conclusions of previously published and incomprehensive studies in Croatia. Therefore, a systematic follow-up of the autopsy findings of induced and spontaneous abortions and newborn deaths in the epidemiology of CNS anomalies is clearly needed. 相似文献
998.
Thin film bulk acoustic wave filter 总被引:1,自引:0,他引:1
Ylilammi M Ellä J Partanen M Kaitila J 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2002,49(4):535-539
Thin film bulk acoustic wave (BAW) resonators (FBAR) are fabricated on a silicon nitride bridge using a ZnO piezolayer on a glass substrate and surface micromachining by standard thin film technology. These resonators exhibit a coupling constant k/sub t//sup 2/=7.8% at the first thickness extensional wave mode and are used as impedance elements in a ladder filter in the 1-GHz frequency band of mobile telecommunications. An electrical equivalent circuit is used to characterize the properties of the resonators and to show how the performance of the filter depends on the parameters of the resonators. 2.5% bandwidth, 2.8-dB insertion loss, and 35-dB selectivity are obtained in a filter with six resonators. The technology can be used to manufacture miniature microwave filters without any additional inductances. 相似文献
999.
Paulo S. André António L. Teixeira Armando N. Pinto Lara P. Pellegrino Berta B. Neto José F. Rocha Joäo L. Pinto Paulo N. Monteiro 《ETRI Journal》2006,28(2):257-259
In this letter, we will evaluate the performance degradation of a 40 km high‐speed (40 Gb/s) optical system, induced by optical fiber variations of the chromatic dispersion induced by temperature changes. The chromatic dispersion temperature sensitivity will be estimated based on the signal quality parameters. 相似文献
1000.
Lukas Schäfer Konstantin Skokov Fernando Maccari Iliya Radulov David Koch Andrey Mazilkin Esmaeil Adabifiroozjaei Leopoldo Molina-Luna Oliver Gutfleisch 《Advanced functional materials》2023,33(4):2208821
Permanent magnets based on neodymium-iron-boron (Nd-Fe-B) alloys provide the highest performance and energy density, finding usage in many high-tech applications. Their magnetic performance relies on the intrinsic properties of the hard-magnetic Nd2Fe14B phase combined with control over the microstructure during production. In this study, a novel magnetic hardening mechanism is described in such materials based on a solid-state phase transformation. Using modified Nd-Fe-B alloys of the type Nd16Febal-x-y-zCoxMoyCuzB7 for the first time it is revealed how the microstructural transformation from the metastable Nd2Fe17Bx phase to the hard-magnetic Nd2Fe14B phase can be thermally controlled, leading to an astonishing increase in coercivity from ≈200 kAm−1 to almost 700 kAm−1. Furthermore, after thermally treating a quenched sample of Nd16Fe56Co20Mo2Cu2B7, the presence of Mo leads to the formation of fine FeMo2B2 precipitates, in the range from micrometers down to a few nanometers. These precipitates are responsible for the refinement of the Nd2Fe14B grains and so for the high coercivity. This mechanism can be incorporated into existing manufacturing processes and can prove to be applicable to novel fabrication routes for Nd-Fe-B magnets, such as additive manufacturing. 相似文献