414 research outputs found
Optical Spectroscopy of Supernova Remnants in M81 and M82
We present spectroscopy of 28 SNR candidates as well as one H II region in
M81, and two SNR candidates in M82. Twenty six out of the M81 candidates turn
out to be genuine SNRs, and two in M82 may be shocked condensations in the
galactic outflow or SNRs. The distribution of [N II]/H{\alpha} ratios of M81
SNRs is bimodal. M81 SNRs are divided into two groups in the spectral line
ratio diagrams: an [O III]-strong group and an [O III]-weak group. The latter
have larger sizes, and may have faster shock velocity. [N II]/H{\alpha} ratios
of the SNRs show a strong correlation with [S II]/H{\alpha} ratios. They show a
clear radial gradient in [N II]/H{\alpha} and [S II]/H{\alpha} ratios: dLog ([N
II]/H{\alpha})/dLog R = -0.018 {\pm} 0.008 dex/kpc and dLog ([S
II]/H{\alpha})/dLog R = -0.016 {\pm} 0.008 dex/kpc where R is a deprojected
galactocentric distance. We estimate the nitrogen and oxygen abundance of the
SNRs from the comparison with shock-ionization models. We obtain a value for
the nitrogen radial gradient, dLog(N/H)/dLogR = -0.023 {\pm} 0.009 dex/kpc, and
little evidence for the gradient in oxygen. This nitrogen abundance shows a few
times flatter gradient than those of the planetary nebulae and H II regions. We
find that five SNRs are matched with X-ray sources. Their X-ray hardness colors
are consistent with thermal SNRs.Comment: 19 pages, 24 figures, 5 tables, ApJ accepte
Bioconversion of CO to formate by artificially designed carbon monoxide:formate oxidoreductase in hyperthermophilic archaea
Ferredoxin-dependent metabolic engineering of electron transfer circuits has been developed to enhance redox efficiency in the field of synthetic biology, e.g., for hydrogen production and for reduction of flavoproteins or NAD(P)+. Here, we present the bioconversion of carbon monoxide (CO) gas to formate via a synthetic CO:formate oxidoreductase (CFOR), designed as an enzyme complex for direct electron transfer between non-interacting CO dehydrogenase and formate dehydrogenase using an electron-transferring Fe-S fusion protein. The CFOR-introduced Thermococcus onnurineus mutant strains showed CO-dependent formate production in vivo and in vitro. The maximum formate production rate from purified CFOR complex and specific formate productivity from the bioreactor were 2.2????????0.2 ??mol/mg/min and 73.1????????29.0 mmol/g-cells/h, respectively. The CO-dependent CO2 reduction/formate production activity of synthetic CFOR was confirmed, indicating that direct electron transfer between two unrelated dehydrogenases was feasible via mediation of the FeS-FeS fusion protein
The first generation of a BAC-based physical map of Brassica rapa
<p>Abstract</p> <p>Background</p> <p>The genus <it>Brassica </it>includes the most extensively cultivated vegetable crops worldwide. Investigation of the <it>Brassica </it>genome presents excellent challenges to study plant genome evolution and divergence of gene function associated with polyploidy and genome hybridization. A physical map of the <it>B. rapa </it>genome is a fundamental tool for analysis of <it>Brassica </it>"A" genome structure. Integration of a physical map with an existing genetic map by linking genetic markers and BAC clones in the sequencing pipeline provides a crucial resource for the ongoing genome sequencing effort and assembly of whole genome sequences.</p> <p>Results</p> <p>A genome-wide physical map of the <it>B. rapa </it>genome was constructed by the capillary electrophoresis-based fingerprinting of 67,468 Bacterial Artificial Chromosome (BAC) clones using the five restriction enzyme SNaPshot technique. The clones were assembled into contigs by means of FPC v8.5.3. After contig validation and manual editing, the resulting contig assembly consists of 1,428 contigs and is estimated to span 717 Mb in physical length. This map provides 242 anchored contigs on 10 linkage groups to be served as seed points from which to continue bidirectional chromosome extension for genome sequencing.</p> <p>Conclusion</p> <p>The map reported here is the first physical map for <it>Brassica </it>"A" genome based on the High Information Content Fingerprinting (HICF) technique. This physical map will serve as a fundamental genomic resource for accelerating genome sequencing, assembly of BAC sequences, and comparative genomics between <it>Brassica </it>genomes. The current build of the <it>B. rapa </it>physical map is available at the <it>B. rapa </it>Genome Project website for the user community.</p
Genome-wide comparative analysis of the Brassica rapa gene space reveals genome shrinkage and differential loss of duplicated genes after whole genome triplication
Euchromatic regions of the Brassica rapa genome were sequenced and mapped onto the corresponding regions in the Arabidopsis thaliana genome
Sinus Histiocytosis with Massive Lymphadenopathy: A Case Report with Pleural Effusion and Cervical Lymphadenopathy
Sinus histiocytosis with massive lymphadenopathy (SHML) is a rare disorder characterized by a nonneoplastic proliferation of distinctive histiocyte cells within lymph node sinuses and lymphatics in extranodal sites. SHML occurs worldwide and is primarily a disease of childhood and early adulthood. A 26-yr-old man presented with painless palpable lymph node in cervical area. Radiographic studies revealed pleural effusion with lymphadenopathy and calcification in mediastinum. The cervical lymph node biopsy showed dilated sinuses filled with histiocytes with clear cytoplasm. The cells stained positive with CD68 and S-100. These cytologic and immunohistochemical findings were considered consistent with the diagnosis of SHML
Impact of Fatty Liver on Acute Pancreatitis Severity
Aim. Acute pancreatitis is typically a mild disease, but some patients develop severe courses. Fatty liver changes are seen in patients with acute pancreatitis, but its clinical significance has not been well-studied. We aimed to investigate the relationship between fatty liver and the severity of acute pancreatitis. Methods. Unenhanced CT images of patients with acute pancreatitis were retrospectively reviewed by a radiologist, and mean hepatic and splenic attenuation was measured in Hounsfield units (HU). Fatty liver was defined as mean hepatic/splenic HU<1. Results. Among 200 patients, fatty liver was found in 67 (33.5%) and nonfatty liver in 133 (66.5%). Compared with patients without fatty liver, the severity of pancreatitis and levels of serum C-reactive protein were higher in fatty liver patients. The prevalence of local complications, persistent organ failure, and mortality were also higher in patients with fatty liver. Even after adjusting for age, sex, body mass index, and cause of pancreatitis, fatty liver was significantly associated with moderately severe or severe acute pancreatitis. Conclusions. Fatty liver may play a prognostic role in acute pancreatitis. Fatty liver could be incorporated into future predictive scoring models
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