3,621 research outputs found
The Properties of Type Ia Supernova Host Galaxies from the Sloan Digital Sky Survey
We investigate the properties and environments of Type Ia Supernova (SN Ia)
host galaxies in the Stripe 82 of the Sloan Digital Sky Survey-II Supernova
Survey centered on the celestial equator. Host galaxies are defined as the
galaxy nearest to the supernova (SN) in terms of angular distance whose
velocity difference from the SN is less than 1000 km s^{-1}. Eighty seven SN Ia
host galaxies are selected from the SDSS Main galaxy sample with the apparent
r-band magnitude m_r < 17.77, and compared with the SDSS Main galaxies. The SN
Ia rates for early and late-type galaxies are 0.81 +- 0.19 SN (100yr)^{-1} and
0.99 +- 0.21 SN (100yr)^{-1}, respectively. We find that the host galaxies have
a color distribution consistent with that of the Main galaxies, regardless of
their morphology. However, host galaxies are on average brighter than the Main
galaxies by ~ 0.3 mag over the range of -18.3 > M_r > -21.3. But the brighter
ends of their luminosity distributions are similar. The distribution of the
distance to the nearest neighbor galaxy shows that SNe Ia are more likely to
occur in isolated galaxies without close neighbors. We also find that the SN Ia
host galaxies are preferentially located in a region close to massive galaxy
clusters compared to the Main galaxies.Comment: 10 pages, 8 figures, accepted for publication on Ap
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Rapid and Quantitative Detection of Zoonotic Influenza A Virus Infection Utilizing Coumarin-derived dendrimer-based Fluorescent Immunochromatographic Strip Test (FICT)
Great efforts have been made to develop robust signal-generating fluorescence materials which will help in improving the rapid diagnostic test (RDT) in terms of sensitivity and quantification. In this study, we developed coumarin-derived dendrimer-based fluorescent immunochromatographic strip test (FICT) assay with enhanced sensitivity as a quantitative diagnostic tool in typical RDT environments. The accuracy of the proposed FICT was compared with that of dot blot immunoassay techniques and conventional RDTs. Through conjugation of coumarin-derived dendrimers with latex beads, fluorescent emission covering broad output spectral ranges was obtained which provided a distinct advantage of easy discrimination of the fluorescent emission of the latex beads with a simple insertion of a long-pass optical filter away from the excitation wavelength. The newly developed FICT assay was able to detect 100 ng/10 μL of influenza A nucleoprotein (NP) antigen within 5 minutes, which corresponded to 2.5-fold higher sensitivity than that of the dot blot immunoassay or conventional RDTs. Moreover, the FICT assay was confirmed to detect at least four avian influenza A subtypes (H5N3, H7N1, H7N7, and H9N2). On applying the FICT to the clinical swab samples infected with respiratory viruses, our FICT assay was confirmed to differentiate influenza H1N1 infection from other respiratory viral diseases. These data demonstrate that the proposed FICT assay is able to detect zoonotic influenza A viruses with a high sensitivity, and it enables the quantitation of the infection intensity by providing the numerical diagnostic values; thus demonstrating enhanced detectability of influenza A viruses
Antibiotic production in Streptomyces is organized by a division of labor through terminal genomic differentiation
One of the hallmark behaviors of social groups is division of labor, where different group members become specialized to carry out complementary tasks. By dividing labor, cooperative groups increase efficiency, thereby raising group fitness even if these behaviors reduce individual fitness. We find that antibiotic production in colonies of Streptomyces coelicolor is coordinated by a division of labor. We show that S. coelicolor colonies are genetically heterogeneous because of amplifications and deletions to the chromosome. Cells with chromosomal changes produce diversified secondary metabolites and secrete more antibiotics; however, these changes reduced individual fitness, providing evidence for a trade-off between antibiotic production and fitness. Last, we show that colonies containing mixtures of mutants and their parents produce significantly more antibiotics, while colony-wide spore production remains unchanged. By generating specialized mutants that hyper-produce antibiotics, streptomycetes reduce the fitness costs of secreted secondary metabolites while maximizing the yield and diversity of these products
A Synonymous Genetic Alteration of LMX1B in a Family with Nail-Patella Syndrome
The gene responsible for nail-patella syndrome, LMX1B, has recently been identified on chromosome 9q. Here we present a patient with nail-patella syndrome and an autosomal dominant pattern of inheritance. A 17-year-old girl visited our clinic for the evaluation and treatment of proteinuria. She had dystrophic nails, palpable iliac horns, and hypoplastic patellae. Electron microscopy of a renal biopsy showed irregular thickening of the glomerular basement membrane. A family history over three generations revealed five affected family members. Genetic analysis found a change of TCG to TCC, resulting in a synonymous alteration at codon 219 in exon 4 of the LMX1B gene in two affected family members. The same alteration was not detected in an unaffected family member. This is the first report of familial nail-patella syndrome associated with an LMX1B in Korea mutation, However, we can not completely rule out the possibility that the G-to-C change may be a single nucleotide polymorphism as this genetic mutation cause no alteration in amino acid sequence of LMX1B
The usefulness of soluble transferrin receptor in the diagnosis and treatment of iron deficiency anemia in children
PurposeSoluble transferrin receptor (sTfR) is a truncated extracellular form of the membrane transferrin receptor produced by proteolysis. Concentrations of serum sTfR are related to iron status and erythropoiesis in the body. We investigated whether serum sTfR levels can aid in diagnosis and treatment of iron deficiency anemia (IDA) in children.MethodsNinety-eight patients with IDA were enrolled and were classified according to age at diagnosis. Group 1 comprised 78 children, aged 6-59 months, and group 2 comprised 20 adolescents, aged 12-16 years.ResultsIn group 1, patients' serum sTfR levels correlated negatively with mean corpuscular volume; hemoglobin (Hb), ferritin, and serum iron levels; and transferrin saturation and positively with total iron binding capacity (TIBC) and red cell distribution width. In group 2, patients' serum sTfR levels did not correlate with ferritin levels and TIBC, but had a significant relationship with other iron indices. Hb and serum sTfR levels had a significant inverse relationship in both groups; however, in group 1, there was no correlation between Hb and serum ferritin levels. In 30 patients of group 1, serum sTfR levels were significantly decreased with an increase in Hb levels after iron supplementation for 1 month.ConclusionSerum sTfR levels significantly correlated with other diagnostic iron parameters of IDA and inversely correlated with an increase in Hb levels following iron supplementation. Therefore, serum sTfR levels can be a useful marker for the diagnosis and treatment of IDA in children
Transcatheter Closure of Multiple Atrial Septal Defects With the Amplatzer Device
Percutaneous device occlusion of secundum atrial septal defect (ASD) has become an accepted alternative to surgical repair. A variety of devices have been used successfully. However, all of them have limitations. We report our experience with two devices used to close multiple ASDs
An Infantile Case of Sturge-Weber Syndrome in Association with Klippel-Trenaunay-Weber Syndrome and Phakomatosis Pigmentovascularis
Sturge-Weber syndrome can be associated with facial port-wine stains and intracranial calcification, and concurrent Klippel-Trenaunay-Weber syndrome has been reported. Klippel-Trenaunay-Weber syndrome is a rare congenital mesodermal phakomatosis characterized by cutaneous hemangiomas, venous varicosities and soft tissue or bone hypertrophy of the affected extremities. This report is presented a rare case of the Sturge-Weber syndrome in combination with the Klippel-Trennaunay syndrome and phakomatosis pigmentovascularis in a 4-month-old infant. He showed nevus flameus on the right leg and both part of the face and back, leptomeningeal angiomatosis on right hemisphere, hypertrophy of the right leg, hemiconvulsion on the left and also evidences of congenital glaucoma and nevus of Ota. Very rare case combined with these three kinds of phakomatosis has been reported
Ballistic Josephson junctions in edge-contacted graphene
Hybrid graphene-superconductor devices have attracted much attention since
the early days of graphene research. So far, these studies have been limited to
the case of diffusive transport through graphene with poorly defined and modest
quality graphene-superconductor interfaces, usually combined with small
critical magnetic fields of the superconducting electrodes. Here we report
graphene based Josephson junctions with one-dimensional edge contacts of
Molybdenum Rhenium. The contacts exhibit a well defined, transparent interface
to the graphene, have a critical magnetic field of 8 Tesla at 4 Kelvin and the
graphene has a high quality due to its encapsulation in hexagonal boron
nitride. This allows us to study and exploit graphene Josephson junctions in a
new regime, characterized by ballistic transport. We find that the critical
current oscillates with the carrier density due to phase coherent interference
of the electrons and holes that carry the supercurrent caused by the formation
of a Fabry-P\'{e}rot cavity. Furthermore, relatively large supercurrents are
observed over unprecedented long distances of up to 1.5 m. Finally, in the
quantum Hall regime we observe broken symmetry states while the contacts remain
superconducting. These achievements open up new avenues to exploit the Dirac
nature of graphene in interaction with the superconducting state.Comment: Updated version after peer review. Includes supplementary material
and ancillary file with source code for tight binding simulation
Regression of Advanced Gastric MALT Lymphoma after the Eradication of Helicobacter pylori
A 66-year-old female presented with a 1-month history of dyspepsia. An initial upper gastrointestinal endoscopy with biopsy revealed a low-grade mucosa-associated lymphoid tissue (MALT) lymphoma. A rapid urease test was positive for Helicobacter pylori. Endoscopic ultrasound (EUS) and computed tomography (CT) revealed a 30×15-mm lymph node (LN) in the subcarinal area. Histopathologic and phenotypic analyses of the biopsy specimens obtained by EUS-guided fine-needle aspiration revealed a MALT lymphoma, and the patient was diagnosed with a stage 4E gastric MALT lymphoma. One year after H. pylori eradication, the lesion had disappeared, as demonstrated by endoscopy with biopsy, CT, fusion whole-body positron emission tomography, and EUS. Here, we describe a patient with gastric MALT lymphoma that metastasized to the mediastinal LN and regressed following H. pylori eradication
Herbal extract THI improves metabolic abnormality in mice fed a high-fat diet
Target herbal ingredient (THI) is an extract made from two herbs, Scutellariae Radix and Platycodi Radix. It has been developed as a treatment for metabolic diseases such as hyperlipidemia, atherosclerosis, and hypertension. One component of these two herbs has been reported to have anti-inflammatory, anti-hyperlipidemic, and anti-obesity activities. However, there have been no reports about the effects of the mixed extract of these two herbs on metabolic diseases. In this study, we investigated the metabolic effects of THI using a diet-induced obesity (DIO) mouse model. High-fat diet (HFD) mice were orally administered daily with 250 mg/kg of THI. After 10 weeks of treatment, the THI-administered HFD mice showed reduction of body weights and epididymal white adipose tissue weights as well as improved glucose tolerance. In addition, the level of total cholesterol in the serum was markedly reduced. To elucidate the molecular mechanism of the metabolic effects of THI in vitro, 3T3-L1 cells were treated with THI, after which the mRNA levels of adipogenic transcription factors, including C/EBPα and PPARγ, were measured. The results show that the expression of these two transcription factors was down regulated by THI in a dose-dependent manner. We also examined the combinatorial effects of THI and swimming exercise on metabolic status. THI administration simultaneously accompanied by swimming exercise had a synergistic effect on serum cholesterol levels. These findings suggest that THI could be developed as a supplement for improving metabolic status
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