Optical properties of iron-based superconductor LiFeAs single crystal

We have measured the reflectivity spectra of the iron based superconductor LiFeAs (Tc = 17.6 K) in the temperature range from 4 to 300 K. In the superconducting state (T < Tc), the clear opening of the optical absorption gap was observed below 25 cm-1, indicating an isotropic full gap formation. In the normal state (T > Tc), the optical conductivity spectra display a typical metallic behavior with the Drude type spectra at low frequencies, but we found that the introduction of the two Drude components best fits the data, indicating the multiband nature of this superconductor. A theoretical analysis of the low temperature data (T=4K < Tc) also suggests that two superconducting gaps best fit the data and their values were estimated as {\Delta}1 = 1.59 meV and {\Delta}2 = 3.15 meV, respectively. Using the Ferrell-Glover-Tinkham (FGT) sum rule and dielectric function {\epsilon}1({\omega}), the superconducting plasma frequency ({\omega}ps) is consistently estimated to be 6,665 cm-1, implying that about 59 % of the free carriers in the normal state condenses into the SC condensate. To investigate the various interband transition processes (for {\omega} > 200 cm-1), we have also performed the local-density approximation (LDA) band calculation and calculated the optical spectra of the interband transitions. The theoretical results provided a qualitative agreement with the experimental data below 4000 cm-1Comment: 19 pages, 5 figures. This paper has been accepted for publication in New Journal of Physic

Primary Esophageal Mucosa-associated Lymphoid Tissue Lymphoma: A Rare Case Report and Review of Other Published Data

The gastrointestinal tract is the most common extranodal site for lymphomas, and mucosa-associated lymphoid tissue lymphoma is the second most common histological lymphoma subtype. However, primary esophageal mucosa-associated lymphoid tissue lymphomas are extremely rare. Few such cases are documented, and the reports demonstrate inconsistent diagnostic and therapeutic strategies. Herein, a 54-year-old man was referred to our hospital for treatment of dysphagia. Esophagogastroduodenoscopy revealed a large, horseshoe-shaped subepithelial mass in the upper esophagus. Endoscopic ultrasonography and computed tomography revealed that the mass was well-demarcated and confined to the muscularis mucosa, with no abnormalities in other organs or lymph nodes. The mass was presumptively diagnosed as benign, and the patient underwent endoscopic mucosal dissection for pathological confirmation and symptom relief. Pathological examination of the dissection specimen revealed that it was a primary esophageal mucosa-associated lymphoid tissue lymphoma. As the patient had an elevated immunoglobulin G level and Helicobacter pylori infection, we administered adjuvant eradication therapy. The patient remains under surveillance and is free of lymphoma recurrence 36 months postoperatively. This case report demonstrates that endoscopic resection and H. pylori eradication are effective treatment strategies for early-stage esophageal mucosa-associated lymphoid tissue lymphoma

Taurine chloramine differentially inhibits matrix metalloproteinase 1 and 13 synthesis in interleukin-1β stimulated fibroblast-like synoviocytes

It has been suggested that taurine chloramine (TauCl) plays an important role in the downregulation of proinflammatory mediators. However, little is known about its effect on the expression of matrix metalloproteinases (MMPs). In this study, we investigated the effects of TauCl on synovial expression of MMPs. The effects of TauCl on MMP expression in IL-1β stimulated fibroblast-like synoviocytes (FLSs) were studied using the following techniques. Real-time PCR and semi-quantitative PCR were employed to analyze the mRNA expression of MMPs. ELISA was used to determine protein levels of MMPs. Western blot analyses were performed to analyze the mitogen-activated protein kinase and inhibitor of nuclear factor-κB (IκB) kinase signalling pathways. Finally, electrophoretic mobility shift assay and immunohistochemistry were used to assess localization of transcription factors. IL-1β increased the transcriptional and translational levels of MMP-1 and MMP-13 in rheumatoid arthritis FLSs, whereas the levels of MMP-2 and MMP-9 were unaffected. TauCl at a concentration of 400 to 600 μmol/l greatly inhibited the transcriptional and translational expression of MMP-13, but the expression of MMP-1 was significantly inhibited at 800 μmol/l. At a concentration of 600 μmol/l, TauCl did not significantly inhibit phosphorylation of mitogen-activated protein kinase or IκB degradation in IL-1β stimulated rheumatoid arthritis FLSs. The degradation of IκB was significantly inhibited at a TauCl concentration of 800 μmol/l. The inhibitory effect of TauCl on IκB degradation was confirmed by electrophoretic mobility shift assay and immunochemical staining for localization of nuclear factor-κB. TauCl differentially inhibits the expression of MMP-1 and MMP-13, and inhibits expression of MMP-1 primarily through the inhibition of IκB degradation, whereas it inhibits expression of MMP-13 through signalling pathways other than the IκB pathway

Optimal target blood pressure for the primary prevention of hemorrhagic stroke: a nationwide observational study

BackgroundThere are few reports on the preventative value of intensive blood pressure (BP) management for stroke, especially hemorrhagic stroke (HS), after new criteria for hypertension (HTN) were announced by the American College of Cardiology/American Heart Association in 2017.AimsThis study aimed to identify the optimal BP for the primary prevention of HS in a healthy population aged between 20 and 65 years.MethodsWe conducted a 10-year observational study on the risk of HS, subclassified as intracerebral hemorrhage (ICH) and subarachnoid hemorrhage (SAH) according to BP categories (e.g., low normal BP, high normal BP, elevated BP, stage 1 HTN, and stage 2 HTN) using the National Health Insurance Service Database.ResultsOut of 8,327,751 participants who underwent a health checkup in 2008, 949,550 were included in this study and observed from 2009 to 2018. The risk of ICH was significantly increased in men with stage 2 HTN {adjusted hazard ratio [aHR] 2.002 [95% confidence interval (CI) 1.203–3.332]} and in women with stage 1 HTN [aHR 2.021 (95% CI, 1.251–3.263)]. The risk of SAH was significantly increased in both men [aHR 1.637 (95% CI, 1.066–2.514)] and women [aHR 4.217 (95% CI, 2.648–6.715)] with stage 1 HTN. Additionally, the risk of HS was significantly increased in men with stage 2 HTN [aHR 3.034 (95% CI, 2.161–4.260)] and in women with stage 1 HTN [aHR 2.976 (95% CI, 2.222–3.986)].ConclusionTo prevent primary HS, including ICH and SAH, BP management is recommended for adults under the age of 65 years with stage 1 HTN

Complete genome sequence of Mycobacterium tuberculosis K from a Korean high school outbreak, belonging to the Beijing family

Mycobacterium tuberculosis K, a member of the Beijing family, was first identified in 1999 as the most prevalent genotype in South Korea among clinical isolates of M. tuberculosis from high school outbreaks. M. tuberculosis K is an aerobic, non-motile, Gram-positive, and non-spore-forming rod-shaped bacillus. A transmission electron microscopy analysis displayed an abundance of lipid bodies in the cytosol. The genome of the M. tuberculosis K strain was sequenced using two independent sequencing methods (Sanger and Illumina). Here, we present the genomic features of the 4,385,518-bp-long complete genome sequence of M. tuberculosis K (one chromosome, no plasmid, and 65.59 % G + C content) and its annotation, which consists of 4194 genes (3447 genes with predicted functions), 48 RNA genes (3 rRNA and 45 tRNA) and 261 genes with peptide signals.

Role of Amphipathic Helix of a Herpesviral Protein in Membrane Deformation and T Cell Receptor Downregulation

Lipid rafts are membrane microdomains that function as platforms for signal transduction and membrane trafficking. Tyrosine kinase interacting protein (Tip) of T lymphotropic Herpesvirus saimiri (HVS) is targeted to lipid rafts in T cells and downregulates TCR and CD4 surface expression. Here, we report that the membrane-proximal amphipathic helix preceding Tip's transmembrane (TM) domain mediates lipid raft localization and membrane deformation. In turn, this motif directs Tip's lysosomal trafficking and selective TCR downregulation. The amphipathic helix binds to the negatively charged lipids and induces liposome tubulation, the TM domain mediates oligomerization, and cooperation of the membrane-proximal helix with the TM domain is sufficient for localization to lipid rafts and lysosomal compartments, especially the mutivesicular bodies. These findings suggest that the membrane-proximal amphipathic helix and TM domain provide HVS Tip with the unique ability to deform the cellular membranes in lipid rafts and to downregulate TCRs potentially through MVB formation

Endoscopic Papillary Balloon Dilation with Large Balloon after Limited Sphincterotomy for Retrieval of Choledocholithiasis

Endoscopic papillary balloon dilation (EBD) for choledocholithiasis is known to be comparable to endoscopic sphincterotomy (EST) especially in cases of small stones. With larger stones, EBD with conventional balloon, which have a diameter of 6-8 mm, was reported as less effective for extraction of stones. We evaluated the efficacy and complications of EBD with large balloons (10-15 mm) after limited EST for retrieval of choledocholithiasis. From February 2005, we have performed EBD with limited EST for retrieval of common bile duct (CBD) stones. The patients who admitted with hyperamylasemia and gallstone pancreatitis were excluded. In cases without CBD dilation, EPBD with 12 mm for 40 seconds was performed. And in cases with CBD dilation, we dilated the sphincters with 15 mm sized balloon for 40 seconds. Total 22 patients (11 of male) were performed EBD with limited EST for retrieval of CBD stones. The median diameter of the stones was 10 mm (5-25 mm). Ten cases had multiple stones and 6 cases periampullary diverticuli. Successful stone removal in the initial session of ERCP with EBD was accomplished in 16 patients (72.7%). And complete retrieval of bile duct stones was achieved in all patients with repeated ERCP. In the aspect of complications, any episodes of perforation, bleeding was not developed. Only one case of mild grade of post-procedural pancreatitis was noted. However, post-procedural hyperamylasemia was developed in 16 cases (68.2%). EBD with larger balloon seems to be a feasible and safe alternative technique for conventional EST in CBD stone extraction

Cutaneous Polyarteritis Nodosa Presented with Digital Gangrene: A Case Report

Cutaneous polyarteritis nodosa (CPAN) is an uncommon form of vasculitis involving small and medium sized arteries of unknown etiology. The disease can be differentiated from polyarteritis nodosa by its limitation to the skin and lack of progression to visceral involvement. The characteristic manifestations are subcutaneous nodule, livedo reticularis, and ulceration, mostly localized on the lower extremity. Arthralgia, myalgia, peripheral neuropathy, and constitutional symptoms such as fever and malaise may also be present. We describe a 34-yr-old woman presented with severe ischemic change of the fingertip and subcutaneous nodules without systemic manifestations as an unusual initial manifestation of CPAN. Therapy with corticosteroid and alprostadil induce a moderate improvement of skin lesions. However, necrosis of the finger got worse and the finger was amputated

Ferromagnetic quasi-atomic electrons in two-dimensional electride.

An electride, a generalized form of cavity-trapped interstitial anionic electrons (IAEs) in a positively charged lattice framework, shows exotic properties according to the size and geometry of the cavities. Here, we report that the IAEs in layer structured [Gd2C]2+·2e- electride behave as ferromagnetic elements in two-dimensional interlayer space and possess their own magnetic moments of ~0.52 μB per quasi-atomic IAE, which facilitate the exchange interactions between interlayer gadolinium atoms across IAEs, inducing the ferromagnetism in [Gd2C]2+·2e- electride. The substitution of paramagnetic chlorine atoms for IAEs proves the magnetic nature of quasi-atomic IAEs through a transition from ferromagnetic [Gd2C]2+·2e- to antiferromagnetic Gd2CCl caused by attenuating interatomic exchange interactions, consistent with theoretical calculations. These results confirm that quasi-atomic IAEs act as ferromagnetic elements and trigger ferromagnetic spin alignments within the antiferromagnetic [Gd2C]2+ lattice framework. These results present a broad opportunity to tailor intriguing ferromagnetism originating from quasi-atomic interstitial electrons in low-dimensional materials