738 research outputs found
Switching Magnetism and Superconductivity with Spin-Polarized Current in Iron-Based Superconductor
We have explored a new mechanism for switching magnetism and
superconductivity in a magnetically frustrated iron-based superconductor using
spin-polarized scanning tunneling microscopy (SPSTM). Our SPSTM study on single
crystal SrVOFeAs shows that a spin-polarized tunneling current can
switch the Fe-layer magnetism into a non-trivial (22) order, not
achievable by thermal excitation with unpolarized current. Our tunneling
spectroscopy study shows that the induced (22) order has
characteristics of plaquette antiferromagnetic order in Fe layer and strongly
suppressed superconductivity. Also, thermal agitation beyond the bulk Fe spin
ordering temperature erases the state. These results suggest a new
possibility of switching local superconductivity by changing the symmetry of
magnetic order with spin-polarized and unpolarized tunneling currents in
iron-based superconductors.Comment: 33 pages, 16 figure
Fixed Drug Eruption Due to Allopurinol: Positive Oral Provocation
A fixed drug eruption (FDE) is characterized by the presence of a solitary or multiple, pruritic, well-circumscribed, erythematous plaques. These lesions have tendency to recur at same sites and heal with residual hyperpigmenation. With repeated attacks, the size and/or number of the lesions may increase. So far, more than 100 drugs have been implicated in causing FDEs, including ibuprofen, sulfonamide, naproxen, and tetracylines. FDE caused by allopurinol has been rarely reported in the literature, but there has been no confirmed case based on oral provocation test. Herein, we report a case of FDE in which the lesions recurred whenever allopurinol was administered for the treatment of gout. A 64-year-old male experienced repeated episodes of well-demarcated dusky erythematous patches on the whole body for 2 months. He took allopurinol intermittently for amelioration of his gout symptom, but denied other medication history. Pruritic erythematous edema developed on the previous lesions 12 hours after oral provocation of 200 mg of allopurinol
MicroRNA-29a suppresses the growth, migration, and invasion of lung adenocarcinoma cells by targeting carcinoembryonic antigen-related cell adhesion molecule 6
AbstractCarcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM6) is an important regulator of cell adhesion, invasion, and metastasis. The aim of this study was to evaluate the functional roles of CEACAM6 in lung adenocarcinoma and to identify miRNAs that inhibit the growth, migration, and invasion of lung adenocarcinoma cells by targeting CEACAM6. CEACAM6 expression is associated with poor prognosis of patients with lung adenocarcinoma, and CEACAM6 has important functional roles in controlling the growth, migration, and invasion of lung adenocarcinoma cells in vitro and in vivo. Furthermore, miR-29a can suppress the growth, migration, and invasion of lung adenocarcinoma cells by targeting CEACAM6. Therefore, miR-29a/CEACAM6 axis represents a potential therapeutic target for treatment of lung adenocarcinoma
Analysis of Facial Deformities in Korean Leprosy
ObjectivesThe clinical features of various facial deformities in Korean leprosy patients were evaluated according to the type of leprosy.MethodsOne hundred ninety six patients with leprosy were examined for various facial deformities using a nasal speculum, endoscope, and digital camera. The frequency and severity of external nasal deformities and septal perforations were evaluated according to the type of leprosy. Eye deformities, ear deformities, and facial palsy were also assessed.ResultsSeventy-one patients (36.2%) displayed external nasal deformities: 28 minimal contractures, three cartilage contractures, two bony-cartilage contractures, and 38 skin defects. The external nasal deformity and severe form deformity in lepromatous types were more frequent compared to other types (P0.05 for each variable). Sixty-one patients (31.1%) had eye deformities and 19 patients (9.7%) had facial nerve palsy, common in the borderline type. No cases of ear deformities were observed.ConclusionKorean patients had characteristic deformities according to the type of leprosy. They were different from those seen in the prior analyses of Caucasian populations
Identification of Gene Expression Signature Modulated by Nicotinamide in a Mouse Bladder Cancer Model
BACKGROUND: Urinary bladder cancer is often a result of exposure to chemical carcinogens such as cigarette smoking. Because of histological similarity, chemically-induced rodent cancer model was largely used for human bladder cancer studies. Previous investigations have suggested that nicotinamide, water-soluble vitamin B3, may play a key role in cancer prevention through its activities in cellular repair. However, to date, evidence towards identifying the genetic alterations of nicotinamide in cancer prevention has not been provided. Here, we search for the molecular signatures of cancer prevention by nicotinamide using a N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN)-induced urinary bladder cancer model in mice. METHODOLOGY/PRINCIPAL FINDINGS: Via microarray gene expression profiling of 20 mice and 233 human bladder samples, we performed various statistical analyses and immunohistochemical staining for validation. The expression patterns of 893 genes associated with nicotinamide activity in cancer prevention were identified by microarray data analysis. Gene network analyses of these 893 genes revealed that the Myc and its associated genes may be the most important regulator of bladder cancer prevention, and the gene expression signature correlated well with protein expression data. Comparison of gene expression between human and mouse revealed that BBN-induced mouse bladder cancers exhibited gene expression profiles that were more similar to those of invasive human bladder cancers than to those of non-invasive human bladder cancers. CONCLUSIONS/SIGNIFICANCE: This study demonstrates that nicotinamide plays an important role as a chemo-preventive and therapeutic agent in bladder cancer through the regulation of the Myc oncogenic signature. Nicotinamide may represent a promising therapeutic modality in patients with muscle-invasive bladder cancer
Wireless thin film transistor based on micro magnetic induction coupling antenna
A wireless thin film transistor (TFT) structure in which a source/drain or a gate is connected directly to a micro antenna to receive or transmit signals or power can be an important building block, acting as an electrical switch, a rectifier or an amplifier, for various electronics as well as microelectronics, since it allows simple connection with other devices, unlike conventional wire connections. An amorphous indium gallium zinc oxide (Ξ±-IGZO) TFT with magnetic antenna structure was fabricated and studied for this purpose. To enhance the induction coupling efficiency while maintaining the same small antenna size, a magnetic core structure consisting of Ni and nanowires was formed under the antenna. With the micro-antenna connected to a source/drain or a gate of the TFT, working electrical signals were well controlled. The results demonstrated the device as an alternative solution to existing wire connections which cause a number of problems in various fields such as flexible/wearable devices, body implanted devices, micro/nano robots, and sensors for the 'internet of things' (IoT).1
Phenotypic and Functional Changes of Peripheral Ly6C(+) T Regulatory Cells Driven by Conventional Effector T Cells
A relatively high affinity/avidity of T cell receptor (TCR) recognition for self-peptide bound to major histocompatibility complex II (self-pMHC) ligands is a distinctive feature of CD4 T regulatory (Treg) cells, including their development in the thymus and maintenance of their suppressive functions in the periphery. Despite such high self-reactivity, however, all thymic-derived peripheral Treg populations are neither homogenous in their phenotype nor uniformly immune-suppressive in their function under steady state condition. We show here that based on the previously defined heterogeneity in the phenotype of peripheral Treg populations, Ly6C expression on Treg marks a lower degree of activation, proliferation, and differentiation status as well as functional incompetence. We also demonstrate that Ly6C expression on Treg in a steady state is either up-or downregulated depending on relative amounts of tonic TCR signals derived from its contacts with self-ligands. Interestingly, peripheral appearance and maintenance of these Ly6C-expressing Treg cells largely differed in an age-dependent manner, with their proportion being continuously increased from perinatal to young adult period but then being gradually declined with age. The reduction of Ly6C(+) Treg in the aged mice was not due to their augmented cell death but rather resulted from downregulation of Ly6C expression. The Ly6C down-regulation was accompanied by proliferation of Ly6C(+) Treg cells and subsequent change into Ly6C-effector Treg with concomitant restoration of immune-suppressive activity. Importantly, we found that this phenotypic and functional change of Ly6C(+) Treg is largely driven by conventional effector T cell population. Collectively, these findings suggest a potential cross-talk between peripheral Treg subsets and effector T cells and provides better understanding for Treg homeostasis and function on maintaining self-tolerance.110Ysciescopu
Tissue expression and antibacterial activity of host defense peptides in chicken
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International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and
reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to
the Creative Commons license, and indicate if changes were made.Abstract
Background
Host defence peptides are a diverse group of small, cationic peptides and are important elements of the first line of defense against pathogens in animals. Expression and functional analysis of host defense peptides has been evaluated in chicken but there are no direct, comprehensive comparisons with all gene family and individual genes.
Results
We examined the expression patterns of all known cathelicidins, Ξ²-defensins and NK-lysin in multiple selected tissues from chickens. CATH1 through 3 were predominantly expressed in the bone marrow, whereas CATHB1 was predominant in bursa of Fabricius. The tissue specific pattern of Ξ²-defensins generally fell into two groups. Ξ²-defensin1-7 expression was predominantly in bone marrow, whereas Ξ²-defensin8-10 and Ξ²-defensin13 were highly expressed in liver. NK-lysin expression was highest in spleen. We synthesized peptide products of these gene families and analysed their antibacterial efficacy. Most of the host defense peptides showed antibacterial activity against E.coli with dose-dependent efficacy. Ξ²-defensin4 and CATH3 displayed the strongest antibacterial activity among all tested chicken HDPs. Microscopic analyses revealed the killing of bacterium by disrupting membranes with peptide treatment.
Conclusions
These results demonstrate dose-dependent antimicrobial effects of chicken HDPs mediated by membrane damage and demonstrate the differential tissue expression pattern of bioactive HDPs in chicken and the relative antimicrobial potency of the peptides they encode
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