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A mechanism describing the synergistic effect of ultrasonic melt treatment (UST) and subsequent fast cooling on the refinement of primary Si particles in a hypereutectic Al−Si alloy was investigated by examining inoculant particles via high-resolution transmission electron microscopy, serial sectioning, and melt filtration. The application of UST activated non-wetting MgAl 2 O 4 particles with diameters of ∼0.5 μm to nucleate the primary Si phase. The cavitation-enhanced wetting of MgAl 2 O 4 particles caused the formation of the AlP phase at the MgAl 2 O 4 interface, further improving the nucleation potential. The cavitation-enhanced wetting and dispersion of inclusions (such as MgAl 2 O 4 ) also resulted in the refinement and de-agglomeration of AlP particles. The UST-induced changes to the inoculant particles ultimately increased their number density, and the observed effects became more pronounced after increasing the degree of undercooling up to 20 K, leading to enhanced refinement of primary Si particles at higher cooling rates (up to 10 2 K s −1 ). [ABSTRACT FROM AUTHOR]

The precipitation behavior of the multicomponent Al–6Mg–9Si–10Cu–10Zn–3Ni (wt%) alloy was investigated during artificial aging at 120 °C through complementary experimental methods including hardness and electrical resistivity measurements, compression testing, differential scanning calorimetry, and transmission electron microscopy. The solution treatment causes the dissolution of the preexisting θ-Al 2 Cu and hcp Zn phases, thereby increasing the concentrations of Zn and Cu species in the Al matrix. During aging, two resistivity peaks (I R , II R ) become visible followed by the appearance of the related hardness peaks (I H , II H ). Spherical Guinier-Preston (GP) zones are formed first and then subsequently transformed into ellipsoidal GP zones. The former process results in the appearance of the I R peak, while the latter process produces the I H peak. During transformation of the ellipsoidal GP zones to hcp Zn, GPI zones are additionally formed, leading to the appearance of II R . The following transformation of the GPI zones into the θ''-Al 3 Cu phase leads to the appearance of the II H peak. Both the ellipsoidal GP zones and hcp Zn phases contain large quantities of Cu atoms, while the θ''-Al 3 Cu phase does not have any Zn atoms. Based on these insights into the structural and chemical compositional evolution of complex precipitates, the strengthening mechanism of the multicomponent alloy during aging has been established. [ABSTRACT FROM AUTHOR]

Crack propagation in high-Mn steel was investigated using in situ transmission electron microscopy. Preferential slips developed in the early stages of deformation on {1 1 1}, followed by the formation of a crack, which propagated along the pre-developed slip traces. A sharp corner was observed at the crack tip along two adjoining {1 1 1} planes. Surface ripples developed when the tip of the crack crossed pre-existing twins on the crack path, which was frequently observed in the surface during the final stage of fracture. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effectiveness and safety of treatment of high-flow priapism (HFP) with superselective transcatheter embolization at nine university hospitals. Materials and Methods: Between May 1994 and October 2006, 27 patients underwent superselective embolization of the cavernous artery for HFP. Trauma was apparent in 22 patients, there was self-administered intracavernosal injection for erectile dysfunction in two, and the remaining three did not recall any penile or perineal trauma. The embolic agents used were autologous blood clot (n = 12), gelatin sponge (n = 12), microcoils combined with gelatin sponge (n = 1), polyvinyl alcohol (n = 1), and N-butyl cyanoacrylate (n = 1). Recurrence of priapism and change in erectile function were evaluated during a mean follow-up of 13 months. Differences in results between patients treated with autologous blood clot versus gelatin sponge were statistically analyzed with use of the chi(2) test. Results: In 24 of 27 patients (89%), a single embolization was sufficient for complete resolution of priapism. Repeat embolization was required in two patients (7%), and in the remaining patient (4%), shunt surgery was performed after embolization as a result of HFP coexisting with corporeal venoocclusive dysfunction. Eighteen of 23 patients (78%) who had premorbid normal erectile function showed maintained potency during the follow-up period. There was no significant difference affecting required repeat embolization (P = .537) and change in quality of erection (P = .615) during the follow-up period between the autologous blood clot and gelatin sponge treatment groups. Conclusions: Superselective transcatheter embolization in the treatment of HFP is effective and ensures a high level of preservation of premorbid erectile function. [ABSTRACT FROM AUTHOR]

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging zoonotic tick-borne disease caused by SFTS virus, which circulates among ticks and their host animals, including wildlife. However, few studies have examined SFTS virus infection in wildlife present in the Republic of Korea (ROK). We evaluated SFTS virus infection in tissue samples from Korean water deer (Hydropotes inermis argyropus), one of the most common wild ungulates in ROK. In this study, we evaluated tissue samples of 129 water deer carcasses collected in 2017 and detected SFTS viral RNA by conventional PCR. SFTS viral RNA was found in 3 of the 129 carcasses, showing a prevalence of 2.3 %; 2 of which were collected in Gyeongsangnam-do and 1 of which was in the Gangwon-do region. Among the 6 internal organs studied, only the spleen samples were positive. Phylogenetic analysis revealed close relationships between deer- and human-derived strains. The medium segments of the three positive cases clustered with genotype B, which is the predominant genotype in ROK. In the small segment, two cases clustered with genotype B, samples 17WD044 and 17WD065. The third sample, 17WD068 from Gangwon-do province, showed genotype A, which circulates mainly in China. The disagreement in the genotypes of the two tested segments suggests a potential reassortment between genotype A and B, resulting in genetic recombination as observed in sample 17WD068, which may be co-circulating in China and Korea. Further studies in wildlife and humans are necessary to understand the genetic characteristics of SFTS viruses circulating in ROK. [ABSTRACT FROM AUTHOR]

Background: This study aims to analyze the outcomes of subtalar distraction arthrodesis (SDA) for calcaneal malunion using structural freeze-dried iliac allograft (FDIA) compared to using autologous iliac bone (AIB).Methods: We retrospectively evaluated 57 consecutive cases (51 patients) of calcaneal malunion between March 2006 and December 2017. All patients were followed for an average of 22.8 months. All cases were treated by SDA using structural FDIA (17 cases, group 1), or AIB (40 cases, group 2). The outcome measures included the American Orthopaedic Foot and Ankle Society ankle-hindfoot (AOFAS) scores, visual analog scale (VAS) pain scores, and radiographic measurements.Results: The mean postoperative 3, 6, and 12 months of AOFAS scores and VAS pain score were significantly better in group 2 than those in group 1 (p < 0.05, for all). There were 3 cases (17.6%) of nonunion in the group 1, whereas the group 2 had 2 cases (5.0%), which did not shown significant difference between two groups (p = 0.492). Although the mean pre-, postoperative, and final follow-up radiologic parameters in both groups were similar, (p > 0.05, for all) the difference of talocalcaneal height, talocalcaneal angle, and talar declination angle from postoperative to final follow-up were significantly bigger in the group 1. (p < 0.05, for all).Conclusion: Although union rate was not significantly different between the two groups, we obtained more favorable clinical and radiologic outcomes in the autologous iliac bone group. Using FDIA without any orthobiological agent for SDA, there were significant more loss of radiological parameters due to inferior incorporation and biomechanical properties. When considering the SDA for calcaneal malunion, routine use of FDIA without any orthobiological agents as an interpositional graft for SDA is not recommended. [ABSTRACT FROM AUTHOR]

Cr and Mo are known to be effective steel alloying elements for high-temperature applications, and they affect steel mechanical properties via carbide formation. Mechanical properties of Cr-Mo steels affected by the carbide evolution were investigated by performing heat treatments, and the treatment duration was determined by the Larson-Miller parameter fitting. The hardness value decreased after heat treatment at 690 °C for 10 h with the decomposition of the bainitic microstructure. The quantified chemical composition results for the carbides were plotted on the Fe-Cr-Mo ternary and Fe-Cr binary composition diagrams to classify the types of carbides formed. Most of the carbides were identified as Fe-rich M 3 C-type carbides at the initial stage of heat treatment. The Fe fraction in the carbides decreased with time while the Cr and Mo fractions increased. The Cr- and Mo-rich carbides were identified as M 23 C 6 - and M 2 C-type, respectively. An increase in the Cr and Mo fractions in the carbides resulted in the decrease in the alloying element concentration in the matrix, which in turn resulted in the deterioration of the solid solution strengthening. Further, it was determined that coarse carbides, observed on the grain boundaries after extended heat treatment, deteriorated the mechanical properties of the alloy. [ABSTRACT FROM AUTHOR]