Phase Identification and Size Evaluation of Mechanically Alloyed Cu-Mg-Ni Powders

Ternary mixture of Cu, Mg, and Ni with the nominal composition of nanocrystalline Cu50Mg25Ni25 (in at.%) was milled for 25 hours. Analysis of an X‐ray diffraction pattern (XRD) and transmission electron microscopy (TEM) was used to characterize the chemical phases and microstructure of the final product, which is shown to consist of ternary alloy of Cu‐Mg‐Ni with FCC structure along with small amounts of FCC MgO and Mg0.85Cu0.15. The good agreement between the size values obtained by XRD and TEM is attributed to the formation of defect‐free grains with no substructure during ball milling. Dynamic recrystallization may be a possible mechanism for the emergence of such small grains (<20 nm). The particle size distribution and morphological changes of Cu–Mg–Ni powders were also analyzed by scanning electron microscopy (SEM). According to the SEM results, the particle size of the powders decreased with increasing milling time. Lattice parameter of the Cu‐Mg‐Ni ternary FCC alloy formed during mechanical alloying increased with increase in milling time from 3.61 to 3.65 Å after 20 hours milling

Reduced gene expression of bikunin as a prognostic marker for renal cell carcinoma

Aim: Experimental and clinical studies showed that bikunin, a Kunitz-type protease inhibitor, found in urine and amniotic fluid has a role in spread of tumor cells by providing a significant reduction in the levels of urokinase-type plasminogen activator (uPA) and its specific receptor urokinase-type plasminogen activator receptor (uPAR). The aim of this study was to investigate expression of bikunin at the mRNA level and screen for mutations in exon sequence in renal cell carcinoma (RCC) tissues. Materials and Methods: Total RNA and DNA were extracted from paired normal and tumor tissues of total 50 RCC (11 papillary, 8 chromophobe, 26 clear cell, and 5 other types) patients (23 females, mean age: 53.55 ± 14.17; 27 males mean age: 62.1 ± 7.92). Bikunin mRNA levels were detected using semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). Mutational screening was performed by using single strand conformation polymorphism (SSCP) method and nucleotide sequence analysis. Results: There was a statistically significant decrease in the 25 (50%) of tumor tissues comparing to normal tissues in terms of mRNA levels of bikunin (Wilcoxon signed rank test, p = 0.0337). According to the classification based on subtypes of RCC; clear cell RCC samples displayed a reduced gene expression (p = 0.0148). Additionally, the patients with the age above 50 had low bikunin expression. The SNP rs80057939 spanning 4th exon of bikunin was detected in 13 tumor tissues. However, it was not statistically significant (p > 0.05). Conclusion: Decreased bikunin mRNA level in renal cells might be associated with poor prognosis of renal carcinoma. Therefore, gene constructs or exogenous administration of bikunin might be a potential adjuvant therapy for RCC treatment. Key Words: Bikunin, nucleotide sequence analysis, prognostic marker, renal cell carcinoma, semi-quantitative RT-PCR

Intravenous immunoglobulin therapy for neonatal hyperbilirubinemia due to ABO or Rh incompatibility [ABO VEYA RH UYUSMAZLIGININ NEDEN OLDUGU NEONATAL HIPERBILIRUBINEMIDE INTRAVENOZ IMMUNGLOBULIN TEDAVISI]

The effect of intravenous immunoglobulin (IVIG) on the number of exchange transfusions, duration of phototherapy and hospitalization in hyperbilirubinemia due to ABO or Rh incompatibility was investigated. Thirty-three term neonates received IVIG (Sando-globulin, 0.5 g/kg, single dose) in addition to the conventional therapy, and 39 term neonates (central group) were treated conventionally (hydration and phototherapy). Rh incompatibility was present in 10 (30.3%) and ABO incompatibility in 23 (66.7%) infants in the IVIG group. Thirteen (33.3%) patients had Rh and 26 (66.7%) patients had ABO incompatibility in the central group. The mean gestational age, birth weight, postnatal age, biochemical and hematologic parameters on admission were similar in the two groups. The mean total bilirubin level after 48 hours of therapy was higher in the control group than the to IVIG group (16.6 and 12.1 mg/dl, respectively, p0.05). Nine infants (23.0%) in the control group required ten exchange transfusions, while two infants (6.0%) required two exchange transfusions (p0.05)

Hardness and microstructural characteristics of rapidly solidified Al-8-16 wt.%Si alloys

Al-Si alloys with nominal composition of Al-8 wt. %Si, Al-12wt.%Si, and Al-16wt.%Si were rapidly solidified by using melt-spinning technique to examine the influence of the cooling rate/conditions on microstructure and mechanical properties. The microstructures of the rapidly solidified ribbons and ingot samples were investigated by the optical microscopy, electron microscopy and X-ray diffraction (XRD) techniques. The results showed that the structures of all melt-spun ribbons were completely composed of finely dispersed alpha-Al and eutectic Si phase, and primary silicon was not observed. The XRD analysis indicated that the solubility of Si in the alpha-Al matrix was greatly increased with rapid solidification. Additionally, mechanical properties of both conventionally cast (ingot) and melt-spun ribbons were examined by using Vickers indenter for one applied load (0.098 N). The hardness values of the melt-spun ribbons were about three times higher than those of ingot counterparts. The high hardness of the rapidly solidified state can be attributed to the supersaturated solid solutions. Besides, hardness values with different applied loads were measured for melt-spun ribbons. The results indicated that Vickers hardness values (H(v)) of the ribbons depended on the applied load. Applying the concept of Hays-Kendall, the load independent hardness values were calculated as 694.0, 982.8 and 1186.8 MN/m(2) for Al-8 wt.%Si, Al-12wt.%Si and Al-16 wt.%Si, respectively. (C) 2004 Elsevier B.V. All rights reserved

Microstructural Investigations of Rapidly Solidified Al-Co-Y Alloys

The alloys with different compositions in the Al-rich corner of the Al-Co-Y ternary system were prepared by conventional casting and further processed by melt-spinning technique. The microstructure and the thermal behavior of the alloys were analyzed by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and differential thermal analysis (DTA). It was found that only rapidly solidified Al85Co7Y8 alloy exhibited the best glass forming ability (GFA) and a fully amorphous structure. Besides, Al85Co13Y2 and Al85Co2Y13 alloy ribbons were fully crystalline, whereas Al85Co10Y5 and Al85Co5Y10 alloy ribbons consisted of some crystalline phases within an amorphous matrix. The SEM results showed the same trend that the crystalline phase fraction decreases with the approaching into best glass former. From DSC results, only Al85Co7Y8 amorphous alloy exhibited a glass transition temperature (Tg) at 569 K, and its supercooled liquid region (ΔTx=Tx−Tg) was found to be 17 K. Moreover, other calculated GFA parameters for this alloy system were also discussed