AT2019 avd: A tidal disruption event with a two-phase evolution

Tidal disruption events (TDEs) can uncover the quiescent super-massive black holes (SMBHs) at the center of galaxies and also offer a promising method to study them. After the disruption of a star by a SMBH, the highly elliptical orbit of the debris stream will be gradually circularized due to the self-crossing, and then the circularized debris will form an accretion disk. The recent TDE candidate AT 2019avd has double peaks in its optical light curve, and the X-ray emerges near the second peak. The durations of the peaks are about 400 and 600 days, respectively, and the separation between them is ~ 700 days. We fit and analyse its spectral energy distribution (SED) in optical/UV, mid-infrared, and X-ray bands. We find that this source can be interpreted as the circularization process in the first phase plus the delayed accretion process in the second phase. Under this two-phase scenario, we use the succession of self-crossing circularization model to fit the first peak, and the delayed accretion model to fit the second peak. The fitting results are consistent with the partial disruption of a 0.9 M_sun star by a 7 * 10^6 M_sun SMBH with the penetration factor \beta ~ 0.6. Furthermore, we find the large-amplitude (by factors up to ~ 5) X-ray variability in AT 2019avd can be interpreted as the rigid-body precession of the misaligned disk due to the Lense-Thirring effect of a spinning SMBH, with the disk precession period of 10 - 25 days.Comment: 14 pages, 11 figures, 4 tables, Submitted to Ap

The Power Spectra of Two Classes of Long-duration Gamma-ray Bursts

We have studied the averaged power density spectra (PDSs) of two classes of long-duration gamma-ray bursts in the recent classification by Balastegui et al.(2001) based on neural network analysis. Both PDSs follow a power law over a wide frequency range with approximately the same slope, which indicates that a process with a self-similar temporal property may underlie the emission mechanisms of both. The two classes of bursts are divided into groups according to their brightness and spectral hardness respectively and each group's PDS was calculated; For both classes, the PDS is found to flatten both with increasing burst brightness and with increasing hardness.Comment: 6 pages, 3 figures, a translated version from published in the Acta Astronomica Sinica, to appear in the Chinese Astronomy & Astrophysics Vol.27, Issue

Marbofloxacin

In the title compound, [systematic name: 9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl­piperazin-1-yl)-7-oxo-7H-pyrido[1,2,3-ij][1,2,4]benzoxadiazine-6-carb­oxy­lic acid], C17H19FN4O4, the carbonyl and carboxyl groups are coplanar with the quinoline ring, making a dihedral angle of 2.39 (2)°. The piperazine ring adopts a chair conformation and the oxadiazinane ring displays an envelope conformation with the CH2 group at the flap displaced by 0.650 (2) Å from the plane through the other five atoms. The mol­ecular structure exhibits an S(6) ring motif, owing to an intra­molecular O—H⋯O hydrogen bond. In the crystal, weak C—H⋯F hydrogen bonds link mol­ecules into layers parallel to the ab plane

Topological surface electronic states in candidate nodal-line semimetal CaAgAs

We investigate systematically the bulk and surface electronic structure of the candidate nodal-line semimetal CaAgAs by angle resolved photoemission spectroscopy and density functional calculations. We observed a metallic, linear, non-$k_z$-dispersive surface band that coincides with the high-binding-energy part of the theoretical topological surface state, proving the topological nontriviality of the system. An overall downshift of the experimental Fermi level points to a rigid-band-like $p$-doping of the samples, due possibly to Ag vacancies in the as-grown crystals.Comment: 6 pages, 5 figure

Quetiapine N-oxide–fumaric acid (2/1)

The title compound (systematic name: 2-{2-[4-(dibenzo[b,f][1,4]thia­zepin-11-yl)piperazin-1-yl 1-oxide]eth­oxy}ethanol–fumaric acid (2/1)), C21H25N3O3S·0.5C4H4O4, is one of the oxidation products of quetiapine hemifumaric acid. In the tricyclic fragment, the central thia­zepine ring displays a boat conformation and the benzene rings are inclined to each other at a dihedral angle of 72.0 (2)°. The piperazine ring adopts a chair conformation with its eth­oxy­ethanol side chain oriented equatorially. In addition to the main mol­ecule, the asymmetric unit contains one-half mol­ecule of fumaric acid, the complete mol­ecule being generated by inversion symmetry. In the crystal, O—H⋯O hydrogen bonds link the components into corrugated layers parallel to bc plane

Interleukin-11-induced capillary leak syndrome in primary hepatic carcinoma patients with thrombocytopenia

<p>Abstract</p> <p>Background</p> <p>Capillary leak syndrome (CLS) is a rare condition characterized by recurrent episodes of generalized edema and severe hypotension associated with hypoproteinemia. Interleukin-11 (IL-11) is a promising therapeutic agent for thrombocytopenia. A direct correlation between IL-11 and CLS has never been reported previously, particularly in patients with hepatic carcinoma.</p> <p>Case presentation</p> <p>We describe two cases of CLS after IL-11 administration in two males with thrombocytopenia. Case 1 was a 46-year-old man with recurrence of hepatic carcinoma who was treated with IL-11 (3 mg per day). After four days of therapy, hypotension and hypoproteinemia were detected. The chest X-ray and B ultrasound of the abdomen showed pleural effusion and ascites. IL-11 was then discontinued, fluid resuscitation was performed, and fresh frozen plasma and packed red blood cells were transfused into this patient. The patient had recovered after 19 days of treatment.</p> <p>Case 2 was a 66-year-old man who had undergone radiofrequency ablation (RFA) for hepatic carcinoma. He was treated with IL-11 (3 mg per day) for thrombocytopenia. After two days of therapy, this patient complained of dyspnea with bilateral edema of the hands. Laboratory values showed hypoproteinemia. IL-11 was stopped and human albumin was transfused at a rate of 10 g per day. On the 4^thday, fluid resuscitation was performed. The patient had recovered after treatment for two weeks.</p> <p>Conclusions</p> <p>The detection of IL-11-induced CLS supports the hypothesis that CLS could be a severe side effect of IL-11 treatment in some patients. These two case reports also demonstrate that patients with hepatic carcinoma who experience this rare form of CLS after treatment with IL-11 seem to respond to a therapeutic regimen that involves hydroxyethyl starch, albumin, and diuretic therapy. Liver cancer patients might be more susceptible to CLS because of poor liver function and hypersplenia. In addition, bleeding after RFA might be a further inducer of CLS.</p

The Nematic Energy Scale and the Missing Electron Pocket in FeSe

Superconductivity emerges in proximity to a nematic phase in most iron-based superconductors. It is therefore important to understand the impact of nematicity on the electronic structure. Orbital assignment and tracking across the nematic phase transition prove to be challenging due to the multiband nature of iron-based superconductors and twinning effects. Here, we report a detailed study of the electronic structure of fully detwinned FeSe across the nematic phase transition using angle-resolved photoemission spectroscopy. We clearly observe a nematicity-driven band reconstruction involving dxz, dyz, and dxy orbitals. The nematic energy scale between dxz and dyz bands reaches a maximum of 50 meV at the Brillouin zone corner. We are also able to track the dxz electron pocket across the nematic transition and explain its absence in the nematic state. Our comprehensive data of the electronic structure provide an accurate basis for theoretical models of the superconducting pairing in FeSe

EFFECTS OF ETHANOL EXTRACT OF RADIX SOPHORAE FLAVESCENTIS ON ACTIVITY OF COLON CANCER HT29 CELLS

This paper mainly studied the inhibitory effect of total ethanol extract of Radix Sophorae Flavescentis on proliferation of colon cancer HT29 cells. By reflux extraction method and with ethanol as extraction solvent, different extracts were obtained at different ethanol concentrations, different solid-liquid ratios, and at different times. And their inhibitory activities against HT29 cells were compared using MTT assay. The experimental results showed that the extraction processes under three conditions can all draw relatively high inhibition rates. The optimum ethanol extraction process conditions were as follows: a solid-liquid ratio of 1:9, 80 min of heat reflux extraction with 95% ethanol

A STUDY ON THE INHIBITORY EFFECT OF SOLANUM LYRATUM THUNB EXTRACT ON LEWIS LUNG CARCINOMA LINES

The objective of this paper was to observe the effects of Solanum lyratum Thunb extract on tumour inhibition, immune function and survival time of tumour-bearing mice. Lung carcinoma-bearing mouse model was established, the tumour-bearing mice were divided into model group, CTX group, Solanum lyratum Thunb extract high-dose group and low-dose group. By the examination of tumour inhibition rate of Solanum lyratum Thunb extract in Lewis lung carcinoma-bearing mice and determination of the number of NK cells and T cell subsets, the survival rate of tumour-bearing mice was observed. Solanum lyratum Thunb extract had some anti-tumour effect in Lewis tumour-bearing mice. The tumour inhibition rate of high-dose group reached 46.28%, and the tumour inhibition rate of low-dose group was 31.42%. Solanum lyratum Thunb extract can improve the NK cell activity of Lewis tumour-bearing mice, increase the number of CD4 cells in the tumour-bearing mice, and significantly increase the survival rate of tumour-bearing mice. The study concluded that Solanum lyratum Thunb extract has some anti-tumour effect and can improve immune function and survival rate of tumour-bearing mice

Observation of Temperature-Induced Crossover to an Orbital-Selective Mott Phase in Ax_{x}Fe2−y_{2-y}Se2_2 (A=K, Rb) Superconductors

In this work, we study the A$_{x}$Fe$_{2-y}$Se$_2$ (A=K, Rb) superconductors using angle-resolved photoemission spectroscopy. In the low temperature state, we observe an orbital-dependent renormalization for the bands near the Fermi level in which the dxy bands are heavily renormliazed compared to the dxz/dyz bands. Upon increasing temperature to above 150K, the system evolves into a state in which the dxy bands have diminished spectral weight while the dxz/dyz bands remain metallic. Combined with theoretical calculations, our observations can be consistently understood as a temperature induced crossover from a metallic state at low temperature to an orbital-selective Mott phase (OSMP) at high temperatures. Furthermore, the fact that the superconducting state of A$_{x}$Fe$_{2-y}$Se$_2$ is near the boundary of such an OSMP constraints the system to have sufficiently strong on-site Coulomb interactions and Hund's coupling, and hence highlight the non-trivial role of electron correlation in this family of iron superconductors