Is the late near-infrared bump in short-hard GRB 130603B due to the Li-Paczynski kilonova?

Short-hard gamma-ray bursts (GRBs) are widely believed to be produced by the merger of two binary compact objects, specifically by two neutron stars or by a neutron star orbiting a black hole. According to the Li-Paczynski kilonova model, the merger would launch sub-relativistic ejecta and a near-infrared/optical transient would then occur, lasting up to days, which is powered by the radioactive decay of heavy elements synthesized in the ejecta. The detection of a late bump using the {\em Hubble Space Telescope} ({\em HST}) in the near-infrared afterglow light curve of the short-hard GRB 130603B is indeed consistent with such a model. However, as shown in this Letter, the limited {\em HST} near-infrared lightcurve behavior can also be interpreted as the synchrotron radiation of the external shock driven by a wide mildly relativistic outflow. In such a scenario, the radio emission is expected to peak with a flux of $\sim 100 \mu$Jy, which is detectable for current radio arrays. Hence, the radio afterglow data can provide complementary evidence on the nature of the bump in GRB 130603B. It is worth noting that good spectroscopy during the bump phase in short-hard bursts can test validity of either model above, analogous to spectroscopy of broad-lined Type Ic supernova in long-soft GRBs.Comment: 4 pages, 2 figures, published in ApJ Lette

A supra-massive magnetar central engine for short GRB 130603B

We show that the peculiar early optical and in particular X-ray afterglow emission of the short duration burst GRB 130603B can be explained by continuous energy injection into the blastwave from a supra-massive magnetar central engine. The observed energetics and temporal/spectral properties of the late infrared bump (i.e., the "kilonova") are also found consistent with emission from the ejecta launched during an NS-NS merger and powered by a magnetar central engine. The isotropic-equivalent kinetic energies of both the GRB blastwave and the kilonova are about $E_{\rm k}\sim 10^{51}$ erg, consistent with being powered by a near-isotropic magnetar wind. However, this relatively small value demands that most of the initial rotational energy of the magnetar $(\sim {\rm a~ few \times 10^{52}~ erg})$ is carried away by gravitational wave radiation. Our results suggest that (i) the progenitor of GRB 130603B would be a NS-NS binary system, whose merger product would be a supra-massive neutron star that lasted for about $\sim 1000$ seconds; (ii) the equation-of-state of nuclear matter would be stiff enough to allow survival of a long-lived supra-massive neutron star, so that it is promising to detect bright electromagnetic counterparts of gravitational wave triggers without short GRB associations in the upcoming Advanced LIGO/Virgo era.Comment: Five pages including 1 Figure, to appear in ApJ

Quantum Algorithm for Solving Quadratic Nonlinear System of Equations

High-dimensional nonlinear system of equations that appears in all kinds of fields is difficult to be solved on a classical computer, we present an efficient quantum algorithm for solving $n$-dimensional quadratic nonlinear system of equations. Our algorithm embeds the equations into a finite-dimensional system of linear equations with homotopy perturbation method and a linearization technique, then we solve the linear equations with quantum linear system solver and obtain a state which is $\epsilon$-close to the normalized exact solution of the original nonlinear equations with success probability $\Omega(1)$. The complexity of our algorithm is $O(\rm{poly}(\rm{log}(n/\epsilon)))$, which provides an exponential improvement over the optimal classical algorithm in dimension $n$.Comment: 9 pages; Modify the format error of tex source fil

Anti-bacterial properties of lactoferrin immobilized wool fabric

A new biological cross-linker, microbial transglutaminase (mTGase), has been used to catalyze the immobilization of lactoferrin onto the wool fabrics, and the antibacterial properties of immobilized wool on both Gram-negative and Gram-positive bacteria are studied. It is found that the minimal inhibitory concentration of lactoferrin against S·aureus and E·coli is 0.5mg/mL and 0.25mg/mL respectively. As compared to the control sample, the amount of lactoferrin adhered onto the wool fabric improves from 4.87 mg.(g fabric)-1 to 12.96 mg.(g fabric)-1, indicating that the crosslinking reaction initiated by mTGase can increase the amount of lactoferrin fixed onto wool fabric obviously. The ratios of bacteriostasis to S.aureus and E.coli of wool fabrics immobilized with lactoferrin are bound to be 57.95% and 69.96% respectively, showing good antibacterial property

Cognitive-enhancing effects of polygalasaponin hydrolysate in aβ(25-35)-induced amnesic mice.

Polygalasaponins are the major active constituents of Polygala tenuifolia exhibiting antiamnesic activity, but their applications are limited due to their toxicities. Evidence showed that the toxicities can be attenuated by hydrolysis. Herein, effects of a hydrolysate of polygalasaponins (HPS) on cognitive impairment induced by Aβ(25-35) were assessed by Morris water maze and step-through passive avoidance tests. The impaired spatial reference memory was improved by HPS (50 and 100 mg/kg). In the acquisition trial of step-through test, HPS (50 and 100 mg/kg) increased the latency into the dark chamber and decreased the error frequency significantly (P < .05). However, no significant change was observed during the retention trial. Additionally, HPS increased the corresponding SOD activities (62.34%, 22.09%) and decreased MDA levels (28.21%, 32.35%) in both cortex and hippocampus as compared to model animals. These results show that HPS may be a useful treatment against amnesia probably via its antioxidant properties.Peer Reviewe

Cognitive-enhancing effects of polygalasaponin hydrolysate in aβ(25-35)-induced amnesic mice.

Polygalasaponins are the major active constituents of Polygala tenuifolia exhibiting antiamnesic activity, but their applications are limited due to their toxicities. Evidence showed that the toxicities can be attenuated by hydrolysis. Herein, effects of a hydrolysate of polygalasaponins (HPS) on cognitive impairment induced by Aβ25−35 were assessed by Morris water maze and step-through passive avoidance tests. The impaired spatial reference memory was improved by HPS (50 and 100mg/kg). In the acquisition trial of step-through test, HPS (50 and 100mg/kg) increased the latency into the dark chamber and decreased the error frequency significantly (P < .05). However, no significant change was observed during the retention trial. Additionally, HPS increased the corresponding SOD activities (62.34%, 22.09%) and decreased MDA levels (28.21%, 32.35%) in both cortex and hippocampus as compared to model animals. These results show that HPS may be a useful treatment against amnesia probably via its antioxidant properties

Evaluation of X-Inactivation Status and Cytogenetic Stability of Human Dermal Fibroblasts after Long-Term Culture

Human primary fibroblasts are a popular type of somatic cells for the production of induced pluripotent stem (iPS) cells. Here we characterized biological properties of primary fibroblasts in terms of cell-growth rate, cytogenetic stability, and the number of inactive X chromosomes during long-term passaging. We produced eight lines of female human dermal fibroblasts (HDFs) and found normal karyotype and expected pattern of X chromosome inactivation (XCI) at low passages (Passage P1-5). However, four out of the eight HDF lines at high passage numbers (≥ P10) exhibited duplicated hallmarks of inactive X chromosome including two punctuate signals of histone H3 lysine 27 trimethylation (H3K27me3) and X inactive-specific transcript (XIST) RNA signals in approximately 8.5–18.5% of the cells. Our data suggest that the copy number of inactive X chromosomes in a subset of female HDF is increased by a two-fold. Consistently, DNA fluorescent in situ hybridization (FISH) identified 3-4 copies of X chromosomes in one nucleus in this subset of cells with two inactive Xs. We conclude that female HDF cultures exhibit a higher risk of genetic anomalies such as carrying an increased number of X chromosomes including both active and inactive X chromosomes at a high passage (≥ P10)

4-[4-(4-Amino-1,2,5-oxadiazol-3-yl)-1,2,5-oxadiazol-3-yl]-1,2,5-oxadiazol-3-amine

The complete molecule of the compound, C6H4N8O3, is generated by a crystallographic twofold rotation axis that runs through the central ring. The flanking ring is twisted by 20.2 (1)° with respect to the central ring. One of the amino H atoms forms an intra­molecular N—H⋯N hydrogen bond; adjacent mol­ecules are linked by N—H⋯N hydrogen bonds forming a chain running along [10-2]

Study of ‘Fingerprints’ for Green Tea from Different Planting Areas in Eastern China

Green tea is one of the main teas in China, which is unfermented and retains more natural substances of fresh tea leaves. This is the preliminary study of&nbsp; application of ‘fingerprints’ based on differences in component composition of green tea. Five green teas from different areas in eastern China are&nbsp; analyzed, which are processed by microwave-assisted solvent (ethanol) extraction method to obtain tea polyphenols, flavonoids, polysaccharides,&nbsp; pigments (thearubigins, theaflavins, theabrownins). The results show that the component composition of five green teas are varied from each other;&nbsp; based on these contents varieties, we have constructed a ‘fingerprint’ and applied linear discriminant analysis (LDA) and hierarchical cluster analysis&nbsp; (HCA) to assist in the identification of these five green teas. This method does not require large, expensive instruments (such as high performance liquid&nbsp; chromatograph, gas chromatograph, mass spectrometer, etc.), and is easy to use, which provides a new avenue for the identification of tea.&nbsp