Introduction: The use of methotrexate (MTX) for rheumatoid arthritis (RA) is increasing. However, the immune suppression state leads to the occurrence of lymphoproliferative disorder (MTX-LPD). The purpose of this stu...
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Introduction: The use of methotrexate (MTX) for rheumatoid arthritis (RA) is increasing. However, the immune suppression state leads to the occurrence of lymphoproliferative disorder (MTX-LPD). The purpose of this study was to describe the findings of 18f-fluorodeoxyglucose (fDG) positron emission tomography (PET) in MTX-LPD patients, and compare it with non-MTX-related malignant lymphoma (ML). Materials and Methods: We retrospectively reviewed 11 MTX-LPD patients (9 female, mean age 68.3 years) and 21 ML patients (7 female, mean age 60.6 years) with a histopathological diagnosis. fDG-PET imaging was performed using a standard oncology procedure. We assessed the disease distribution based on fDG-PET images and measured the maximum standardized up take values (SUVmax) for each region. Results: Mean values of SUVmax in MTX-LPD and ML were 14.6 and 17.2, respectively (p = 0.49). In MTX-LPD, 55 lesions met the Cotswold classification, consisting of 37 nodal and 18 extranodal lesions. In ML, 82 lesions were found, consisting of 68 nodal and 14 extranodal lesions. MTX-LPD showed a higher incident of the involvement in extranodal lesions throughout the whole body (p < 0.001). Conclusion: Because this disease occurs widely throughout the whole body, we need to pay attention to the less frequent sites as well when performing PET imaging in patients with MTX-LPD.
Nb and f co-doped anatase TiO2 layers were deposited by low pressure chemical vapor deposition (LPCVD) at pressure of 3 mtorr using titanium-tetra-iso-propoxide (TTIP), O2 and Nbf5 as precursor, oxidant and dopant res...
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Nb and f co-doped anatase TiO2 layers were deposited by low pressure chemical vapor deposition (LPCVD) at pressure of 3 mtorr using titanium-tetra-iso-propoxide (TTIP), O2 and Nbf5 as precursor, oxidant and dopant respectively. Resistivity beyond 100 Ωcm for undoped layer was decreased with increasing supply of the dopant and dependent on the supply ratio of O2 to TTIP and decreased to 0.2 Ωcm by the optimization. X-ray fluorescent spectroscopy showed Nb-content in the layer was decreased with the O2-supply ratio. X-ray photo-spectroscopy indicated that f substituted O-site in TiO2 by O2-supply but carbon-contamination and f missing substitution in the O-site were significantly increased by excess O2-supply. further, it was suggested that the substituted f played an important role to reduce resistivity without significant contribution of O-vacancies. XRD spectra showed f missing substitution in the O-site degraded the crystallinity.
Carbon fiber reinforced magnesium matrix (C f /Mg) composites are suitable for lightweight structures which have received more interest for its excellent mechanical properties. C f /Mg composites were fabricated by li...
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Carbon fiber reinforced magnesium matrix (C f /Mg) composites are suitable for lightweight structures which have received more interest for its excellent mechanical properties. C f /Mg composites were fabricated by liquid-solid extrusion following vacuum infiltration, which integrated melting, pouring, infiltration and liquid-solid forming under high infiltration pressure. The tensile strength was determined by tensile tests on flat specimens in displacement controlled mode according to ASTM standard D 3552. The specimens were fixed in suitable clamping force for the specimens avoiding to be destroyed by compression. Specimens were elongated in 0.1 mm/min speed till finally fractured. The results indicated that the tensile strength of the C f /Mg composite reached 366 MPa, which was improved by 144% compared with that of matrix alloy.
fly ash particles are usually spherical and based on their chemical composition;they are categorized into two classes: C and f. This study compares the microstructural, mechanical and thermal properties of extruded ri...
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fly ash particles are usually spherical and based on their chemical composition;they are categorized into two classes: C and f. This study compares the microstructural, mechanical and thermal properties of extruded rigid PVC foam composites reinforced with class C and class ffly ash. The mechanical properties: such as tensile and flexural strength of composites containing class C fly ash were superior to the composites containing class ffly ash particles. Composites containing 6 phr class C fly ash showed a 24% improvement in the tensile strength in comparison to a mere 0.5% increase in composites reinforced with class ffly ash. Similarly, the addition of 6 phr of class ffly ash to the PVC foam matrix resulted in a 5.74% decrease in the flexural strength, while incorporating the same amount of class C fly ash led to a 95% increase in flexural strength. The impact strength of the composites decreased as the amount of either type offly ash increased in the composites indicating that fly ash particles improve the rigidity of the PVC foam composites. No significant changes were observed in the thermal properties of the composites containing either type offly ash particles. However, the thermo-mechanical properties measured by DMA indicated a steep increase in the viscoelastic properties of composites reinforced with class C flyash. The microstructural properties studied by Scanning Electron Microscopy (SEM) confirmed that fly ash particles were mechanically interlocked in the PVC matrix with good interfacial interaction with the matrix. However, particle agglomeration and debonding was observed in composites reinforced with higher amounts offly ash.
The present study reports the ultrasonic velocity measurements on the dispersions of thermotropic Cholesteric Liquid Crystal (CLC) doped with low concentrations offerroelectric nanopowder (NP) of Barium titanate (BaT...
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The present study reports the ultrasonic velocity measurements on the dispersions of thermotropic Cholesteric Liquid Crystal (CLC) doped with low concentrations offerroelectric nanopowder (NP) of Barium titanate (BaTiO 3 ). Addition of NP to CLC alters the pitch of the liquid crystals. The velocity of a 2 MHz ultrasonic wave passing through pure CLC as well as doped CLC and their density has been measured as a function of temperature. The low concentration of NP in CLC host increases the orientational ordering of the CLC. This results in the structural changes that affect the Intermolecular free Length (L f ). This length L f increases with rising temperature showing abrupt changes near phase transition temperatures (PTTs). Larger values of L f indicate that the structural readjustment in the sample is in the direction of more compressible phase or distant packing of molecules. These modified characteristics of CLC play an important role in the designing of new materials.
A class of second order ( f , α , ρ , d , E )-convex functions and their generalization on functions involved, weak, strong, and converse duality theorems are established for a second order Mond-Weir type dual problem.
A class of second order ( f , α , ρ , d , E )-convex functions and their generalization on functions involved, weak, strong, and converse duality theorems are established for a second order Mond-Weir type dual problem.
Thin - walled pipes are not suitable for measuring fracture toughness parameters which are of vital importance in pipes because the crack failure is the most common in pipes. They are not suitable because it is imposs...
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Thin - walled pipes are not suitable for measuring fracture toughness parameters which are of vital importance in pipes because the crack failure is the most common in pipes. They are not suitable because it is impossible to make standard specimens for measuring the fracture toughness like SENB or CT specimens from the thin wall of the pipe. Lot of researches noticed this problem, but only few are found the good and cheap alternative solution for measuring the fracture toughness. Gubeljak and Matvienko proposed so - called Pipe - Ring specimen (PRS) or Pipe - Ring Notched Bend specimen (PRNB) as alternative solution to the SENB specimen. Until now, only the idealized geometry of PRS specimen is analysed, so specimen which is not cut out from the real pipe but made from plate. On this way, the residual stresses are neglected. The aim of this work is to estimate the hoop residual stresses in the real pipes used in boiler industry, produced by hot - rolling technique, so seamless pipes. These kinds of pipes are delivered only normalized, but not stress relieved too. Therefore, there are surly residual stresses present in pipes which are result of manufacturing technique, but also of uneven cooling after the production process. Within this work, hoop stress as the most relevant for pipes is estimated by two methods: incremental hole drilling method and splitting method. Although residual stresses are cause of collapse of many constructions, still in most cases of analysis and design of individual parts, structures and plants residual stresses are not taken into consideration. Residual stresses surly have some effect on the fatigue behaviour of materials as well as on the fracture toughness of material, therefore it is recommended to take them into account while calculating the lifetime of component or structure.
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