Low Surface Brightness Galaxies Selected by Different Model Fitting

We present a study of low surface brightness galaxies(LSBGs) selected by fitting the images for all the galaxies inα.40 SDSS DR7 sample with two kinds of single-component models and two kinds of two-component models(disk+bulge):single exponential,single sersic,exponential+deVaucular(exp+deV),and exponential+sérsic(exp+ser).Under the criteria of the B band disk central surface brightness μ_(0,disk)(B)≥22.5 mag arcsec^(-2) and the axis ratio b/a> 0.3,we selected four none-edge-on LSBG samples from each of the models which contain 1105,1038,207,and 75 galaxies,respectively.There are 756 galaxies in common between LSBGs selected by exponential and sersic models,corresponding to 68.42% of LSBGs selected by the exponential model and 72.83% of LSBGs selected by the sersic model,the rest of the discrepancy is due to the difference in obtaining μ_(0) between the exponential and sersic models.Based on the fitting,in the range of 0.5≤n≤1.5,the relation of μ_(0) from two models can be written as μ_(0,sérsic)-μ_(0,exp)=-1.34(n-1).The LSBGs selected by disk+bulge models(LSBG_(2)comps) are more massive than LSBGs selected by single-component models(LSBG_1comp),and also show a larger disk component.Though the bulges in the majority of our LSBG_(2)comps are not prominent,more than 60% of our LSBG_(2)comps will not be selected if we adopt a single-component model only.We also identified 31 giant low surface brightness galaxies(gLSBGs) from LSBG_(2)comps.They are located at the same region in the color-magnitude diagram as other gLSBGs.After we compared different criteria of gLSBGs selection,we find that for gas-rich LSBGs,M_(*)> 10^(10)M_⊙ is the best to distinguish between gLSBGs and normal LSBGs with bulge.

Low Surface Brightness Galaxies from BASS+MzLS with Machine Learning

From ∼5000 deg^(2) of the combination of the Beijing–Arizona Sky Survey and Mayall z-band Legacy Survey which is also the northern sky region of the Dark Energy Spectroscopic Instrument (DESI) Legacy Imaging Surveys, we selected a sample of 31,825 candidates of low surface brightness galaxies (LSBGs) with the mean effective surface brightness 24.2<μ_(eff.g)<28.8 mag arcsec^(−2) and the half-light radius 2.″5 < r_(eff)<20″ based on the released photometric catalog and the machine learning model. The distribution of the LSBGs is bimodal in the g−r color, indicating the two distinct populations of the blue (g−r< 0.60) and red (g−r> 0.60) LSBGs. The blue LSBGs appear spiral, disk or irregular while the red LSBGs are spheroidal or elliptical and spatially clustered. This trend shows that the color has a strong correlation with galaxy morphology for LSBGs. In the spatial distribution, the blue LSBGs are more uniformly distributed while the red ones are highly clustered, indicating that red LSBGs preferentially populate a denser environment than the blue LSBGs. Besides, both populations have a consistent distribution of ellipticity (median ∈∼ 0.3), half-light radius (median r_(eff) ∼ 4″) and Sérsic index (median n=1), implying the dominance of the full sample by the round and disk galaxies. This sample has definitely extended the studies of LSBGs to a regime of lower surface brightness, fainter magnitude and broader other properties than the previously Sloan Digital Sky Survey-based samples.

Spontaneous resolution of idiopathic intestinal obstruction after pneumonia: A case report

BACKGROUND Duodenal obstruction is a common clinical scenario that can either be mechanical or a pseudo-obstruction.Clinical management of intestinal obstruction starts from localization and proceeds to histological examination of the stenotic intestine.Systemic factors and dysfunction of distant organs might contribute to the development of intestinal obstruction.Here,we report a unique case of idiopathic mechanical duodenal obstruction,which resolved spontaneously after 3 mo of conservative treatment,but was followed by intestinal pseudo-obstruction.CASE SUMMARY An 84-year-old woman presented with worsened postprandial vomiting accompanied by prolonged pneumonia.Thorough noninvasive investigations revealed complete circumferential stenosis in the descending duodenum without known cause.Exploratory surgery was postponed due to septic shock and possible pulmonary fungal infection.Conservative treatment for 3 mo for ileus and control of pulmonary infection resolved the intestinal obstruction completely.Unfortunately,2 wk later,she had regurgitation and postprandial vomiting again,complicated by deteriorating wheezing and dyspnea.Computed tomography revealed a dilated stomach and proximal duodenum without new intestinal stricture or pulmonary infiltration.The patient fully recovered after combined treatment with antireflux agents,enema,prokinetics,and bronchodilators.CONCLUSION This complicated case highlights the inter-relationship of local and systemic contributions to ileus and gut dysfunction,which requires multidisciplinary treatment.

Identification of a Novel Four and a Half LIM Domain 1 Mutation in a Chinese Male Presented with Hypertrophic Cardiomyopathy and Mild Skeletal Muscle Hypertrophy

To the Editor：The human four and a half LIM domain 1 （FHL1） gene,located on Xq26.3,encodes for a protein with only LIM domains.LIM domains,named after their initial discovery in the proteins Lin11,Isl-1,and Mec-3,are cysteine-rich protein motifs composed of two contiguous zinc finger domains separated by a two-amino acid residue hydrophobic linker.