2,4-Dihydr­oxy-N′-(4-methoxy­benzyl­idene)benzohydrazide

The mol­ecule of the title compound, C15H14N2O4, displays a trans configuration with respect to the hydrazide C=N bond. The dihedral angle between the two benzene rings is 15.0 (2)°. In the crystal structure, mol­ecules are linked through inter­molecular O—H⋯N and O—H⋯O hydrogen bonds, forming layers parallel to the ab plane; an intramolecular N—H⋯O hydrogen bond is also present

A novel DEAH-box helicase 37 mutation associated with differences of sex development

ObjectiveTo determine the genetic etiology of a family pedigree with two patients affected by differences of sex development (DSD).MethodsAssess the clinical characteristics of the patients and achieve exome sequencing results and in vitro functional studies.ResultsThe 15-year-old proband, raised as female, presented with delayed puberty and short stature associated with atypical genitalia. Hormonal profile showed hypergonadotrophic hypogonadism. Imaging studies revealed the absence of a uterus and ovaries. The karyotype confirmed a 46, XY pattern. Her younger brother presented with a micropenis and hypoplastic scrotum with non-palpable testis and hypospadias. Laparoscopic exploration was performed on the younger brother. Streak gonads were found and removed due to the risk of neoplastic transformation. Post-operative histopathology showed the co-existence of Wolffian and Müllerian derivatives. Whole-exome sequencing identified a novel mutation (c.1223C>T, p. Ser408Leu) in the Asp-Glu-Ala-His-box helicase 37 gene, which was found to be deleterious by in silico analysis. Segregation analysis of the variant displayed a sex-limited, autosomal dominant, maternal inheritance pattern. In vitro experiments revealed that the substitution of 408Ser by Leu caused decreased DHX37 expression both at the mRNA and protein levels. Moreover, the β-catenin protein was upregulated, and the p53 protein was unaltered by mutant DHX37.ConclusionsWe described a novel mutation (c.1223C>T, p. Ser408Leu) of the DHX37 gene associated with a Chinese pedigree consisting of two 46, XY DSD patients. We speculated that the underlying molecular mechanism might involve upregulation of the β-catenin protein

A multi band study of the optically dark GRB 051028

Observations were made of the optical afterglow of GRB 051028 with the Lulin observatory's 1.0 m telescope and the WIDGET robotic telescope system. R band photometric data points were obtained on 2005 October 28 (UT), or 0.095-0.180 days after the burst. There is a possible plateau in the optical light curve around 0.1 days after the burst; the light curve resembles optically bright afterglows (e.g. GRB 041006, GRB 050319, GRB060605) in shape of the light curve but not in brightness. The brightness of the GRB 051028 afterglow is 3 magnitudes fainter than that of one of the dark events, GRB 020124. Optically dark GRBs have been attributed to dust extinction within the host galaxy or high redshift. However, the spectrum analysis of the X-rays implies that there is no significant absorption by the host galaxy. Furthermore, according to the model theoretical calculation of the Ly$\alpha$ absorption to find the limit of GRB 051028's redshift, the expected $R$ band absorption is not high enough to explain the darkness of the afterglow. While the present results disfavor either the high-redshift hypothesis or the high extinction scenario for optically dark bursts, they are consistent with the possibility that the brightness of the optical afterglow, intrinsically dark.Comment: 5page, 5 figures, 1 table, accepted for publication in PASJ Letter. PASJ styl

Probing the nature of high- z short GRB 090426 with its early optical and X-ray afterglows

GRB 090426 is a short-duration burst detected by Swift (  s in the observer frame and  s in the burst frame at z = 2.609 ). Its host galaxy properties and some gamma-ray-related correlations are analogous to those seen in long-duration gamma-ray bursts (GRBs), which are believed to be of a massive star origin (so-called Type II GRBs). We present the results of its early optical observations with the 0.8-m Tsinghua University–National Astronomical Observatory of China Telescope (TNT) at Xinglong Observatory and the 1-m LOAO telescope at Mt Lemmon Optical Astronomy Observatory in Arizona. Our well-sampled optical afterglow light curve covers from to 10 4  s after the GRB trigger. It shows two shallow decay episodes that are likely due to energy injection, which end at and 7100 s, respectively. The decay slopes after the injection phases are consistent with each other ( ). The X-ray afterglow light curve appears to trace the optical, although the second energy-injection phase was missed due to visibility constraints introduced by the Swift orbit. The X-ray spectral index is without temporal evolution. Its decay slope is consistent with the prediction of the forward shock model. Both X-ray and optical emission are consistent with being in the same spectral regime above the cooling frequency ( ). The fact that is below the optical band from the very early epoch of the observation provides a constraint on the burst environment, which is similar to that seen in classical long-duration GRBs. We therefore suggest that death of a massive star is the possible progenitor of this short burst.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79209/1/j.1365-2966.2010.17419.x.pd

Probing the Nature of High-z Short GRB 090426 with Its Early Optical and X-ray Afterglows

GRB 090426 is a short duration burst detected by Swift ($T_{90}\sim 1.28$ s in the observer frame, and $T_{90}\sim 0.33$ s in the burst frame at $z=2.609$). Its host galaxy properties and some $\gamma$-ray related correlations are analogous to those seen in long duration GRBs, which are believed to be of a massive-star origin (so-called Type II GRBs). We present the results of its early optical observations with the 0.8-m TNT telescope at Xinglong observatory, and the 1-m LOAO telescope at Mt. Lemmon Optical Astronomy Observatory in Arizona. Our well-sampled optical afterglow lightcurve covers from $\sim 90$ seconds to $\sim 10^4$ seconds post the GRB trigger. It shows two shallow decay episodes that are likely due to energy injection, which end at $\sim 230$ seconds and $\sim 7100$ seconds, respectively. The decay slopes post the injection phases are consistent with each other ($\alpha\simeq 1.22$). The X-ray afterglow lightcurve appears to trace the optical, although the second energy injection phase was missed due to visibility constraints introduced by the {\em Swift} orbit. The X-ray spectral index is $\beta_X\sim 1.0$ without temporal evolution. Its decay slope is consistent with the prediction of the forward shock model. Both X-ray and optical emission is consistent with being in the same spectral regime above the cooling frequency ($\nu_c$). The fact that $\nu_c$ is below the optical band from the very early epoch of the observation provides a constraint on the burst environment, which is similar to that seen in classical long duration GRBs. We therefore suggest that death of a massive star is the possible progenitor of this short burst.Comment: 7 pages, 1 figures, 2 tables, revised version, MNRAS, in pres