Enhanced microstructure homogeneity of extruded Mg-6Zn-0.5Zr alloy by Ca addition

Department of Materials Science EngineeringCommercial Mg-6Zn-0.5Zr (ZK60) alloys with different contents of alloyed Ca were subjected to indirect extrusion processing at an initial temperature of 250 ℃ and subsequently the effect of Ca alloying on the microstructure of the extruded alloys was investigated with particular emphasis on recrystallization and grain growth during the hot extrusion. It was found that alloying with Ca results in the refinement of recrystallized α-Mg grains and also it contributes to enhancing the homogeneity of grain size in the extruded condition. Besides, two different types of second-phase precipitates, MgZn2 and Ca2Mg6Zn3, were found to exist in the Ca-containing ZKX600 alloy, although only MgZn2 precipitates appeared in the ZK60 alloy without alloyed Ca. Such microstructural changes in grain size and its homogeneity attained by Ca addition are mainly attributed to the presence of Ca2Mg6Zn3 precipitates, which appear to have better thermal stability than MgZn2 precipitates.ope

Full Tendon Transposition Augmented with Posterior Intermuscular Suture and Recession - Resection Surgery

Purpose: To report an effect of the full tendon transposition augmented with posterior intermuscular suture and recession-resection surgery, for the patient with monocular elevation deficiency (MED) and large exotropia. Methods: Interventional case report. Full tendon transposition augmented with posterior intermuscular suture and recession-resection surgery was performed for a 26-year-old male patient had monocular elevation deficiency (MED) and large exotropia. Results: Preoperative angle of deviation was 56 prism diopters (PD) hypotropia and 45 PD right exotropia, compared with 18 PD left hypertropia and 10 PD right esotropia postoperatively. Essotropia persisted after 2.5 years, however, and so the right medial rectus was recessed after removal of the previous posterior intermuscular suture. At a three-year follow-up after the second surgery, alignment was straight in the primary position at near and far distances. Conclusions: Full tendon transposition augmented with posterior intermuscular suture and recession-resection surgery was effective for a patient with MED associated with significant horizontal deviation, and a second operation was easily performed when overcorrection occurred.ope

In Utero Exposure to 2,3,7,8-Tetrachlorodibenzo-p-Dioxin Affects the Development of Reproductive System in Mouse

PURPOSE: Exposure of male reproductive organs to 2,3,7,8-Tetrachlorodibenzo-p-Dioxin (TCDD) has been reported to cause developmental changes. In this study, we evaluated the effects of in utero TCDD exposure on male reproductive development. MATERIALS AND METHODS: Pregnant C57BL/6 mice were administered a single intraperitoneal injection of TCDD (1microgram/kg) on gestation day (GD) 15. The offspring were examined in the immature stage on postnatal day (PND) 30 and in the mature stage on PND 60. The testes were examined for histological changes, androgen receptor (AR), proliferating cell nuclear antigen (PCNA) and apoptosis following the measurement of morphological changes. RESULTS: Anogenital distance (AGD) and testis weights were reduced by TCDD exposure both on PND 30 and PND 60 while body weights and length of male offspring were not affected by TCDD. The regular sperm developmental stage was impaired with TCDD treatment on PND 30. However, no difference was found between the control group and TCDD groups on PND 60. Simultaneously, the expression of AR was also reduced on PND 30, while it was increased on PND 60 compared with the control group. The expression of PCNA was decreased whereas apoptosis was not affected by TCDD both on PND 30 and PND 60. CONCLUSION: These results suggest that in utero exposure to TCDD influences the development of testes by inhibiting the expression of AR and PCNA. Moreover, the adverse effects of TCDD on male offspring reduced over timeope

Distance and Reddening of the Isolated Dwarf Irregular Galaxy NGC 1156

We present a photometric estimation of the distance and reddening values to the dwarf irregular galaxy NGC 1156, which is one of the best targets to study the isolated dwarf galaxies in the nearby universe. We have used the imaging data sets of the Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) High Resolution Channel (HRC) of the central region of NGC 1156 (26" X 29") available in the HST archive for this study. From the (U-B, B-V) color-color diagram, we first estimate the total (foreground + internal) reddening toward NGC 1156 of E(B-V) =0.35 +/- 0.05 mag, whereas only the foreground reddening was previously known to be E(B-V)=0.16 mag (Burstein & Heiles) or 0.24 mag (Schlegel, Finkbeiner, & Davis). Based on the brightest stars method, selecting the three brightest blue supergiant (BSG) stars with mean B magnitude of = 21.94 mag and the three brightest red supergiant (RSG) stars with mean V magnitude of = 22.76 mag, we derive the distance modulus to NGC 1156 to be (m-M)_{0,BSG} = 29.55 mag and (m-M)_{0,RSG} = 29.16 mag. By using weights of 1 and 1.5 for the distance moduli from using the BSGs and the RSGs, respectively, we finally obtain the weighted mean distance modulus to NGC 1156 (m-M)_0 = 29.39 +/- 0.20 mag (d = 7.6 +/- 0.7 Mpc), which is in very good agreement with the previous estimates. Combining the photometry data of this study with those of Karachentsev et al. gives smaller distance to NGC 1156, which is discussed together with the limits of the data.Comment: 18 pages, 8 figures, Accepted by PASJ (2012 Apr issue

Dreaming of the future of stroke: translation of bench to bed

Stroke is one of the leading causes of death and the most common cause of disability in adults. Remarkable advances in stroke research have been achieved during the past decades. Stroke fatalities have decreased significantly worldwide owing to improved stroke care because of increased public awareness of stroke symptoms, improved acute stroke therapy, and improved stroke prevention approaches. There are currently significant developments in new technologies with the potential to be used daily in clinical practice in patients with stroke. In this review, we have selected and discussed some of the key areas related to stroke, namely big data, artificial intelligence, precision medicine, medical devices, and stem cells

Transport properties of graphene with one-dimensional charge defects

We study the effect of extended charge defects in electronic transport properties of graphene. Extended defects are ubiquitous in chemically and epitaxially grown graphene samples due to internal strains associated with the lattice mismatch. We show that at low energies these defects interact quite strongly with the 2D Dirac fermions and have an important effect in the DC-conductivity of these materials.Comment: 6 pages, 5 figures. published version: one figure, appendix and references adde