Hydrogen absorption and corrosion studies of zone-refined iron

The lattice constants of zone-refined iron filings and iron whiskers are 2.86623 and 2.86626 Å at 25°C respectively. Their thermal expansion coefficients are both the same, 12.1 x 10⁻⁶ /°C at temperatures 10 - 65°C. The influence of hydrogen on the lattice constant of iron was investigated and it was found that hydrogen has no effect (within the limits of errors) on the lattice constant of iron at room temperature regardless of the charging methods. However, at elevated temperatures hydrogen expands the iron lattice due to increased solubility of the gas. The lattice constant of iron in vacuum and in a hydrogen atmosphere was determined at elevated temperatures and found to follow the empirical equations: in vacuum, a= 2.86522 + 4.28 x 10⁻⁵t and in hydrogen (under conditions of the experiments), a = 2.86554 + 2.45565 x 10⁻⁵t + 6.78828 X 10⁻⁸t² - 7.16922 x 10⁻¹¹ x t³ + 2.08773 x 10⁻¹⁴t⁴, where a is the lattice constant of alpha iron at temperatures between room and 910°C. The lattice constant of gamma iron in the range 910 - 1130°C is the same in vacuum and in hydrogen (under the conditions of the experiments) and follows the equation, a= 3.5771 +7.75 -5 x 10⁻⁵t, where a is the lattice constant at t°C. The thermal expansion coefficients of iron in vacuum are found to stay at a nearly constant value of 14.8 x 10⁻⁶ /°C in the range 200 - 800°C. In a hydrogen atmosphere under the conditions of the experiments it is found to have a maximum (17.3 x 10⁻⁶ /°C) at about 450°C. The effect of hydrogen on the lattice constant of iron at elevated temperatures is discussed. The influence of hydrogen on the density and electrical resistivity of pure iron was investigated and it was found that hydrogen has an effect neither on the density of pure iron nor on its electrical resistivity between 100 and 600°C. The density of zone-refined iron was determined to be 7.8745 ± 0.0002 g/cm³ at 25°C and the actual number of atoms per unit cell was calculated to be very close to the ideal number of two. Hence, the structure of zone-refined iron is sound or perfect. The corrosion pattern of zone-refined iron in some acids (concentrated hydrochloric acid, 2 N sulfuric acid, 1.5 N nitric acid, 25 percent aqueous solution of aqua regia, and concentrated hydrofluoric acid) was studied and the following facts were found: (1) during corrosion of zone-refined iron, three main corrosion patterns develop on the surface and (2) all patterns consist of parallel steps and facets which are arranged in certain crystallographic orientations, and (3) the surface of these steps is mainly close to the planes (110) and (122), (112) and (123). An anodic dissolution study of zone-refined iron in hydrochloric and sulfuric acids showed no measurable amount of anodic disintegration. --Abstract, pages ii-iv

A Novel Mechanism of PPARγ Regulation of TGFβ1: Implication in Cancer Biology

Peroxisome proliferator-activated receptor-γ (PPARγ) and retinoic acid X-receptor (RXR) heterodimer, which regulates cell growth and differentiation, represses the TGFβ1 gene that encodes for the protein involved in cancer biology. This review will introduce the novel mechanism associated with the inhibition of the TGFβ1 gene by PPARγ activation, which regulates the dephosphorylation of Zf9 transcription factor. Pharmacological manipulation of TGFβ1 by PPARγ activators can be applied for treating TGFβ1-induced pathophysiologic disorders such as cancer metastasis and fibrosis. In this article, we will discuss the opposing effects of TGFβ on tumor growth and metastasis, and address the signaling pathways regulated by PPARγ for tumor progression and suppression

High-precision realization of robust quantum anomalous Hall state in a hard ferromagnetic topological insulator

The discovery of the quantum Hall (QH) effect led to the realization of a topological electronic state with dissipationless currents circulating in one direction along the edge of a two dimensional electron layer under a strong magnetic field. The quantum anomalous Hall (QAH) effect shares a similar physical phenomenon as the QH effect, whereas its physical origin relies on the intrinsic spin-orbit coupling and ferromagnetism.Here we report the experimental observation of the QAH state in V-doped (Bi,Sb)2Te3 films with the zero-field longitudinal resistance down to 0.00013+-0.00007h/e2 (~3.35+-1.76 ohm), Hall conductance reaching 0.9998+-0.0006e2/h and the Hall angle becoming as high as 89.993+-0.004degree at T=25mK. Further advantage of this system comes from the fact that it is a hard ferromagnet with a large coercive field (Hc>1.0T) and a relative high Curie temperature. This realization of robust QAH state in hard FMTIs is a major step towards dissipationless electronic applications without external fields.Comment: 16 pages, 4 figures, this is the final version, accepted by Nature Materials, forthcomin

Comparison of Conventional Excision via a Sublabial Approach and Transnasal Marsupialization for the Treatment of Nasolabial Cysts: A Prospective Randomized Study

ObjectivesSurgical excision via a sublabial approach is considered the standard treatment for nasolabial cysts. Although transnasal marsupialization has been proposed as an alternative method, no prospective study has compared the effectiveness of these techniques. We thus compared the surgical procedure, operating time, postoperative pain, complications, and recurrence rate between the two surgical methods.MethodsTwenty patients diagnosed with nasolabial cysts were allocated randomly into two groups according to the surgical technique. In the sublabial approach group, the cysts were excised completely using a sublabial approach, while in the transnasal marsupialization group, the cysts were marsupialized transnasally under the guidance of nasal endoscopes. The pure operating time was measured and postoperative pain was evaluated using a visual analog scale. Complications after the procedure were assessed and recurrence was determined according to the clinical symptoms and postoperative radiologic findings.ResultsThe transnasal marsupialization group had significantly shorter operating times, less postoperative pain, lower complication rates, and shorter duration of side effects than the sublabial approach group. No recurrence occurred in either group after a 1-yr follow-up period.ConclusionAlthough both methods are effective for treating nasolabial cysts, the transnasal marsupialization of nasolabial cysts has many benefits over the conventional sublabial approach. Therefore, we propose that transnasal marsupialization be the treatment of choice for nasolabial cysts

Clinical Features and Prognosis of HLA-B27 Positive and Negative Anterior Uveitis in a Korean Population

Clinical features and prognosis of HLA-B27 positive anterior uveitis (AU) were assessed compared with HLA-B27 negative AU in a Korean population, based on the medical records of AU patients seen at a university hospital. Twenty-seven HLA-B27 negative, idiopathic AU patients (group I) and 55 HLA-B27 positive AU patients (group II) were studied. HLA-B27 positive group was further divided into 29 with associated systemic disease (seronegative spondyloarthropathy) (group IIA) and 26 without associated systemic disease (group IIB). Significantly more severe anterior chamber inflammation in terms of anterior chamber cells (P=0.006) and hypopyon formation (P=0.034) was observed with higher frequency of AU attacks (P=0.007) in the HLA-B27 positive group than in the HLA-B27 negative group. Systemic/periocular steroids were required in significantly more patients in the HLA-B27 positive group than in the HLA-B27 negative group (P=0.015). However, no significant differences were observed for final ocular and visual outcomes between these two groups. Associated systemic disease made no significant difference in the clinical features and prognosis in the HLA-B27 positive AU patients. In conclusion, despite more severe inflammation and a higher recurrence rate, HLA-B27 positive AU shows similar good final ocular and visual outcomes compared to HLA-B27 negative, idiopathic AU in a Korean population

Long-term follow-up results of endoscopic treatment of gastroesophageal reflux disease with the MUSE TM endoscopic stapling device

Background The initial 6-month data for MUSE™ (Medigus, Omer, Israel) endoscopic stapling device were reported (Zacherl et al. in Surg Endosc 29:220–229, 2015). The current study aims to evaluate the long-term clinical outcome of 37 patients who received endoscopic gastroesophageal reflux disease (GERD) treatment with the MUSE™ device. Methods Efficacy and safety data for 37 patients were analyzed at baseline, 6 months, and 4 years post-procedure. In one center (IU), efficacy and safety data were evaluated at baseline, 6 months post-procedure, and then annually up to 4 years. Results No new complications have been reported in our long-term analysis. The proportions of patients who remained off daily PPI were 83.8 % (31/37) at 6 months and 69.4 % (25/36) at 4 years post-procedure. GERD-Health Related Quality of Life (HRQL) scores (off PPI) were significantly decreased from baseline to 6 months and 4 years post-procedure. The daily dosage of GERD medications, measured as omeprazole equivalents (mean ± SD, mg), decreased from 66.1 ± 33.2 at baseline to 10.8 ± 15.9 at 6 months and 12.8 ± 19.4 at 4 years post-procedure (P < 0.01). Conclusions In our multi-center prospective study, the MUSE™ stapling device appears to be safe and effective in improving symptom scores as well as reducing PPI use in patients with GERD. These results appeared to be equal to or better than those of the other devices for endoluminal GERD therapy. Future studies with larger patient series, sham control group, and greater number of staples are awaited

Clinical efficacy of body mass index as predictor of in vitro fertilization and embryo transfer outcomes

The aim of this study was to evaluate the clinical efficacy of body mass index (BMI) as a predictor of in vitro fertilization and embryo transfer (IVF-ET) outcomes. Two hundred twenty-three IVF-ET cycles in 164 patients under 37 yr using GnRH agonist long protocols were included in this retrospective study. All of the selected cases were divided into two groups by a cutoff of 24 kg/m2 and these two groups were compared in regard to the outcomes of IVF-ET. There were no significant differences between group 1 (BMI or = 24 kg/m2) in age, basal serum FSH level, estradiol (E2) level and endometrial thickness on hCG day, number of retrieved oocytes and transferred embryos. However, higher doses of gonadotropins were used in group 2 (30.8+/-12.7 ampoules vs. 35.4+/-15.3 ampoules, p=0.051). The clinical pregnancy rate was significantly lower in group 2 (25.9% vs. 10.5%, p=0.041) and implantation rate tended to be lower in group 2 (12.7% vs. 6.8%, p=0.085). BMI > or = 24 kg/m2 can be a candidate prognosticator of IVF-ET outcomes

Immunogenicity of influenza vaccination in patients with cancer receiving immune checkpoint inhibitors

Among prospectively enrolled adult patients with cancer receiving immune checkpoint inhibitors (ICIs; n = 46) or cytotoxic agents (n = 90), seroprotection and seroconversion rates after seasonal quadrivalent influenza vaccinations were higher with ICI than with cytotoxic chemotherapy. These results support annual influenza vaccinations for cancer patients receiving ICIs.