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The environment of a γ -ray burst has an important influence on the evolution of jet dynamics and its afterglow. Here we investigate the afterglow polarizations in a stratified medium with the equal arrival time surface (EATS) effect. Polarizations of multiband afterglows are predicted. The effects of the parameters of the stratified medium on the afterglow polarizations are also investigated. We found the influences of the EATS effect on the afterglow polarizations become important for off-axis detections and polarization degree (PD) bumps move to later times with the EATS effect. Even if the magnetic field configurations, jet structure, and observational angles are fixed, polarization properties of the jet emission could still evolve. Here, we assume a large-scale ordered magnetic field in the reverse-shock region and a two-dimensional random field in the forward-shock region. Then, PD evolution is mainly determined by the evolution of the f 32 parameter (the flux ratio between the reverse-shock region and forward-shock region) at the early stage and by the evolution of the bulk Lorentz factor γ at the late stage. Through the influences on the f 32 or γ, the observational energy band, observational angles, and the parameters of the stratified medium will finally affect the afterglow polarizations. [ABSTRACT FROM AUTHOR]

The reverse shock (RS) model is generally introduced to interpret the optical afterglows with the rapid rising and decaying, such as the early optical afterglow of GRB 990123 (which is also called the optical flash). In this paper, we collected 11 gamma-ray burst (GRB) early optical afterglows, which have signatures of dominant RS emission. Since the temporal slopes of the optical flashes are determined by both the medium density distribution index k and the electron spectral index p, we apply the RS model of the thin shell case to the optical flashes and determine the ambient medium of the progenitors. We find that the k value is in the range of 0–1.5. The k value in this paper is consistent with the result in Yi et al., where the forward shock model was applied to some onset bumps. However, the method adopted in this paper is only applicable to GRB afterglows with significant sharp rising and decaying RS emission. Our results indicate that the RS model can also be applied to confirm the circumburst medium, further implying that GRBs may have diverse circumburst media. [ABSTRACT FROM AUTHOR]

Plastic packaging waste, such as polyethylene terephthalate (PET) has increased significantly in recent decades, arousing a considerable and serious public concern regarding the environment, economy, and policy. Plastic recycling is a useful tool to mitigate this issue. Here, a feasible study was performed to investigate the potential of a novel method for identifying virgin and recycled PET. Ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) was combined with various chemometrics, as a simple and reliable method that achieved a high discrimination rate for 105 batches of virgin PET (v-PET) and recycled PET (r-PET) based on 202 non-volatile organic compounds (NVOCs). Making use of orthogonal partial least-squares discrimination analysis (OPLS-DA) together with non-parametric tests, 26 marker compounds (i.e. 12 intentionally added substances (IAS) and 14 non-intentionally added substances (NIAS) as well as 31 marker compounds (i.e. 11 IAS and 20 NIAS) obtained from positive and combination of positive and negative ionization modes of UPLC-Q-TOF-MS, respectively, were successfully identified. Moreover, 100% accuracy was obtained using a decision tree (DT). Cross-discrimination based on misclassified samples using various chemometrics allowed the prediction accuracy to be improved and to identify a large sample set, thus greatly enhancing the application scope of this method. The possible origins of these detected compounds can be the plastic itself, as well as contamination from food, medicine, pesticides, industry-related substances, and degradation and polymerization products. As many of these compounds are toxic, especially those pesticide related, this indicates an urgent requirement for closed loop recycling. Overall, this analytical method provides a quick, accurate, and robust way to distinguish virgin from recycled PET and thus addresses the issue of potential virgin PET adulteration thereby detecting fraud in the area of PET recycling. [ABSTRACT FROM AUTHOR]

We briefly introduce the disadvantages for Type Ia supernovae (SNe Ia) as standard candles to measure the universe, and suggest Gamma-ray bursts (GRBs) can serve as a powerful tool for probing the properties of high redshift universe. We use GRBs as distance indicators in constructing the Hubble diagram at redshifts beyond the current reach of SNe Ia observations. Since the progenitors of long GRBs (LGRBs) are confirmed to be massive stars, they are deemed as an effective approach to study the cosmic star formation rate (SFR). A detailed representation of how to measure high- SFR using GRBs is presented. Moreover, first stars can form only in structures that are suitably dense, which can be parametrized by defining the minimum dark matter halo mass . must play a crucial role in star formation. The association of LGRBs with the collapses of massive stars also indicates that the GRB data can be applied to constrain the minimum halo mass and to investigate star formation in dark matter halos. [ABSTRACT FROM AUTHOR]

Inflammatory bowel disease (IBD) affects millions of people worldwide. Although the etiology of this disease is uncertain, accumulating evidence indicates a key role for the activated mucosal immune system. In the present study, we examined the effects of the natural compound fraxinellone on dextran sulfate sodium (DSS)-induced colitis in mice, an animal model that mimics IBD. Treatment with fraxinellone significantly reduced weight loss and diarrhea in mice and alleviated the macroscopic and microscopic signs of the disease. In addition, the activities of myeloperoxidase and alkaline phosphatase were markedly suppressed, while the levels of glutathione were increased in colitis tissues following fraxinellone treatment. This compound also decreased the colonic levels of interleukin (IL)-1β, IL-6, IL-18 and tumor necrosis factor (TNF)-α in a concentration-dependent manner. These effects of fraxinellone in mice with experimental colitis were attributed to its inhibition of CD11b + macrophage infiltration. The mRNA levels of macrophage-related molecules in the colon, including intercellular adhesion molecule 1 (ICAM1), vascular cell adhesion molecule 1 (VCAM1), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX2), were also markedly inhibited following fraxinellone treatment. The results from in vitro assays showed that fraxinellone significantly reduced lipopolysaccharide (LPS)-induced production of nitric oxide (NO), IL-1β and IL-18 as well as the activity of iNOS in both THP-1 cells and mouse primary peritoneal macrophages. The mechanisms responsible for these effects were attributed to the inhibitory role of fraxinellone in NF-κB signaling and NLRP3 inflammasome activation. Overall, our results support fraxinellone as a novel drug candidate in the treatment of colonic inflammation. [ABSTRACT FROM AUTHOR]

The sample of time-delay gravitational lenses appropriate for studying the geometry of the Universe continues to grow as dedicated campaigns, such as the Dark Energy Survey, the (Very Large Telescope) VLT Survey Telescope (VST) ATLAS survey, and the Large Synoptic Survey Telescope, complete their census of high-redshift sources. This catalogue now includes hundreds of strong lensing systems, at least 31 of which have reasonably accurate time-delay measurements. In this paper, we use them to compare the predictions of two competing Friedmann–Lemaître–Robertson–Walker models: flat Lambda cold dark matter (ΛCDM), characterized by two adjustable parameters (H 0 and Ωm), and the R h = ct universe (with H 0 as the single free variable). Over the past decade, the latter has accounted for the data better than the standard model, most recently the emergence of well-formed galaxies discovered by JWST at cosmic dawn. Here, we show that the current sample of time-delay lenses favours R h = ct with a likelihood of ∼ |$84{{\ \rm per\ cent}}$| versus ∼ |$16{{\ \rm per\ cent}}$| for the standard model. This level of accuracy will greatly improve as the ongoing surveys uncover many thousands of additional lens systems over the next several years. [ABSTRACT FROM AUTHOR]

Pogostemon cablin Benth (PCB) is a well-known traditional Chinese medicine that has been used for treatment of many ailments for several centuries. In presently, the chemical profiling and quality control study of PCB has mainly concentrated on the volatile fractions. However, the non-volatile chemical profile of PCB was still unclear. In this study, 73 non-volatile constituents (i.e., 33 flavonoids, 21 organic acids, 9 phenylpropanoids, 4 sesquiterpenes, 3 alkaloids, and 3 other types of compounds) were identified and characterized in PCB using high performance liquid chromatography coupled with quadruple time-of-flight tandem mass spectrometry (HPLC-Q-TOF-MS). Meanwhile, to assess PCB samples, an established HPLC-Q-TOF-MS fingerprint was combined with multivariate statistical analysis that included similarity analysis (SA), hierarchical cluster analysis (HCA), principal component analysis (PCA), and orthogonal partial least squares-discriminant analysis (OPLS-DA). The PCB samples could be classified into two groups (herbal decoction pieces and processed medicinal materials), and acteoside, isoacteoside, 4′,6-Dihydroxy-5,7-dimethoxyflavone, pachypodol and pogostone were screened as the potential chemical markers that attributed classification. In addition, nine representative components (pachypodol, vicenin-2, apigenin, rhamnocitrin, acteoside, isoacteoside, chlorogenic acid, azelaic acid and pogostone) in PCB were simultaneously determined by using an ultra-high-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry (UPLC-QQQ-MS/MS). This study is the first to describe the chemical profile of PCB using liquid chromatography tandem mass spectrometry, which would improve our understanding of the substance basis of PCB and is helpful to the PCB further quality evaluation. [Display omitted] • The non-volatile chemical profile of Pogostemon cablin Benth (PCB) was revealed for the first time using HPLC-Q-TOF-MS. • An established HPLC-Q-TOF-MS fingerprint of PCB combined with the multivariate statistical analysis used to assess PCB samples. • A quick and sensitive UPLC-QQQ-MS/MS method was established and used to simultaneously quantify nine representative components in the PCB samples. • Five components were screened and identified as the potential chemical markers for the classification of herbal decoction pieces and processed medicinal materials of PCB. [ABSTRACT FROM AUTHOR]

Crohn's disease is a common, chronic inflammatory bowel condition characterized by remission and relapse. Accumulating evidence indicates that activated T cells play an important role in this disease. In the present study, we aimed to examine the effect of beauvericin, a natural cyclic peptide, on 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis in mice, which mimics Crohn's disease. Beauvericin significantly reduced weight loss, diarrhea and mortality, accompanied with notable alleviation of macroscopic and microscopic signs. In addition, this compound decreased serum levels of tumor necrosis factor (TNF)-α and interferon (IFN)- γ in a concentration-dependent manner in mice with experimental colitis. These effects of beauvericin are attributed to its inhibition on activated T cells. Flow cytometry and immunoblot assay data showed that beauvericin suppressed T-cell proliferation, activation and IFN-γ-STAT1-T-bet signaling and subsequently led to apoptosis of activated T cells by suppressing Bcl-2 and phosphorylated Bad as well as increasing cleavage of caspase-3, -9, -12 and PARP. Furthermore, inhibition of PI3K/Akt signaling, which was an upstream regulator of cell activation and survival in activated T cells, contributed to the effect of beauvericin. Overall, these results supported beauvericin as a novel drug candidate for the treatment of colonic inflammation mainly by targeting PI3K/Akt in activated T cells. [ABSTRACT FROM AUTHOR]

A long-duration gamma-ray burst (GRB) has been widely thought to arise from the collapse of a massive star, and it has been suggested that its ambient medium is a homogenous interstellar medium (ISM) or a stellar wind. There are two shocks when an ultra-relativistic fireball that has been ejected during the prompt gamma-ray emission phase sweeps up the circumburst medium: a reverse shock that propagates into the fireball, and a forward shock that propagates into the ambient medium. In this paper, we investigate the temporal evolution of the dynamics and emission of these two shocks in an environment with a general density distribution of n∝R–k (where R is the radius) by considering thick-shell and thin-shell cases. A GRB afterglow with one smooth onset peak at early times is understood to result from such external shocks. Thus, we can determine the medium density distribution by fitting the onset peak appearing in the light curve of an early optical afterglow. We apply our model to 19 GRBs and find that their k values are in the range of 0.4-1.4, with a typical value of k ∼ 1, implying that this environment is neither a homogenous ISM with k = 0 nor a typical stellar wind with k = 2. This shows that the progenitors of these GRBs might have undergone a new mass-loss evolution. [ABSTRACT FROM AUTHOR]

Abstract: In the present study, we aimed to investigate the immunosuppressive activity of vaticaffinol, a resveratrol tetramer isolated from Vatica mangachapoi, on T lymphocytes both in vitro and in vivo, and further explored its potential molecular mechanism. Resveratrol had a wide spectrum of healthy beneficial effects with multiple targets. Interestingly, its tetramer, vaticaffinol, exerted more intensive immunosuppressive activity than resveratrol. Vaticaffinol significantly inhibited T cells proliferation activated by concanavalin A (Con A) or anti-CD3 plus anti-CD28 in a dose- and time-dependent manner. It also induced Con A-activated T cells undergoing apoptosis through mitochondrial pathway. Moreover, this compound prevented cells from entering S phase and G2/M phase during T cells activation. In addition, vaticaffinol inhibited ERK and AKT signaling pathways in Con A-activated T cells. Furthermore, vaticaffinol significantly ameliorated ear swelling in a mouse model of picryl chloride-induced ear contact dermatitis in vivo. In most of the aforementioned experiments, however, resveratrol had only slight effects on the inhibition of T lymphocytes compared with vaticaffinol. Taken together, our findings suggest that vaticaffinol exerts more preferable immunosuppressive activity than its precursor resveratrol both in vitro and in vivo by affecting multiple targets against activated T cells. [Copyright &y& Elsevier]

Abstract: In the present paper, we aimed to examine the novel effects of cerebroside D, a glycoceramide compound, on murine experimental colitis. Cerebroside D significantly reduced the weight loss, mortality rate and alleviated the macroscopic and microscopic appearances of colitis induced by dexran sulfate sodium. This compound also decreased the levels of TNF-α, IFN-γ and IL-1β in intestinal tissue of mice with experimental colitis in a concentration-dependent manner, accompanied with markedly increased serum level of IL-10. Cerebroside D inhibited proliferation and induced apoptosis of T cells activated by concanavalin A or anti-CD3 plus anti-CD28 antibodies. The compound did not show an effect on naive lymphocytes but prevented cells from entering S phase and G2/M phase during T cells activation. Moreover, the treatment of cerebroside D led to apoptosis of activated T cells with the cleavage of caspase 3, 9, 12 and PARP. These results showed multiple effects of cerebroside D against activated T cells for a novel approach to treatment of colonic inflammation. [Copyright &y& Elsevier]

Abstract: Adenosine triphosphate–sensitive potassium (KATP) channels are suggested to be involved in pathogenesis of neuropathic pain, but remain underinvestigated in primary afferents and in the spinal cord. We examined alterations of KATP channels in rat spinal cord and tested whether and how they could contribute to neuropathic pain. The results showed that protein expression for KATP channel subunits SUR1, SUR2, and Kir6.1, but not Kir6.2, were significantly downregulated and associated with thermal hyperalgesia and mechanical allodynia after sciatic nerve injury. Spinal administration of a KATP channel opener cromakalim (CRO, 5, 10, and 20μg, respectively) prevented or suppressed, in a dose-dependent manner, the hyperalgesia and allodynia. Nerve injury also significantly increased expression and phosphorylation of connexin 43, an astroglial gap junction protein. Such an increase of phosphorylation of connexin 43 was inhibited by CRO treatment. Furthermore, preadministration of an astroglial gap junction decoupler carbenoxolone (10μg) completely reversed the inhibitory effects of CRO treatment on the hyperalgesia and allodynia and phosphorylation of NR1 and NR2B receptors and the subsequent activation of Ca2+-dependent signals Ca2+/calmodulin-dependent kinase II and cyclic adenosine monophosphate (cAMP) response element binding protein. These findings suggest that nerve injury–induced downregulation of the KATP channels in the spinal cord may interrupt the astroglial gap junctional function and contribute to neuropathic pain, thus the KATP channels opener can reduce neuropathic pain probably partly via regulating the astroglial gap junctions. This study may provide a new strategy for treating neuropathic pain using KATP channel openers in the clinic. [Copyright &y& Elsevier]

Abstract: We calculate the diffuse high energy (TeV–PeV) neutrino emission from hyperflares of soft-gamma repeaters (SGRs), like the hyperflare risen from SGR 1806-20 on December 27 of 2004, within the framework of the fireball model. The fireball model for gamma-ray bursts (GRBs) can explain well the main features of this hyperflare and the subsequent multi-frequency afterglow emission. The expected rate, , of such hyperflares is well in excess of the GRBs rate. Our result shows that the contribution to the diffuse TeV–PeV neutrino background from such hyperflares is less than 10% of the contribution from GRBs. We also discuss the high energy cosmic rays (CRs) from these sources. [Copyright &y& Elsevier]

Abstract: In the present paper, the effect of Fumigaclavine C, a fungal metabolite, on experimental colitis was examined. Fumigaclavine C, when administered intraperitoneally once a day, significantly reduced the weight loss and mortality rate of mice with experimental colitis induced by intrarectally injection of 2, 4, 6-trinitrobenzene sulfonic acid (TNBS). This compound also markedly alleviated the macroscopic and microscopic appearances of colitis. Furthermore, Fumigaclavine C, given both in vivo and in vitro, showed a marked inhibition on the expression of several inflammatory cytokines, including IL-1β, IL-2, IL-12α, IFN-γ, TNF-α as well as MMP-9 in sacral lymph node cells, colonic patch lymphocytes and colitis tissues from the TNBS colitis mice. Meanwhile, the compound caused a dose-dependent reduction in IL-2 and IFN-γ from the lymphocytes at the protein level and MMP-9 activity. These results suggest that Fumigaclavine C may alleviate experimental colitis mainly via down-regulating the production of Th1 cytokines and the activity of matrix metalloproteinase. [Copyright &y& Elsevier]

Perovskite solar cells (PSCs) are expected to profoundly impact the photovoltaic society on account of its high‐efficiency and cost‐saving manufacture. As a key component in efficient PSCs, the hole transport layer (HTL) can selectively collect photogenerated carriers from perovskite absorbers and prevent the charge recombination at interfaces. However, the mainstream organic HTLs generally require multi‐step synthesis and hygroscopic dopants that significantly limit the practical application of PSCs. Here, a self‐organized percolative architecture composed of narrow bandgap oxides (e.g., Co3O4, NiO, CuO, Fe2O3, and MnO2) and wide bandgap SrCO3 oxysalt as efficient HTLs for PSCs is presented. The percolation of dual phases offers nanosized hole transport pathways and optimized interfacial band alignments, enabling significantly improved charge collection compared with the single phase HTLs. As a consequence, the power conversion efficiency boosted from 8.08% of SrCO3 based device and 15.47% of Co3O4 based device to 21.84% of Co3O4‐SrCO3 based one without notable hysteresis. The work offers a new direction by employing percolative materials for efficient charge transport and collection in PSCs, and would be applicable to a wide range of opto‐electronic thin film devices. [ABSTRACT FROM AUTHOR]

[Display omitted] [ABSTRACT FROM AUTHOR]

The use of time-delay gravitational lenses to examine the cosmological expansion introduces a new standard ruler with which to test theoretical models. The sample suitable for this kind of work now includes 12 lens systems, which have thus far been used solely for optimizing the parameters of ΛCDM. In this paper, we broaden the base of support for this new, important cosmic probe by using these observations to carry out a one-on-one comparison between competing models. The currently available sample indicates a likelihood of ∼70%-80% that the Rh = ct universe is the correct cosmology versus ∼20%-30% for the standard model. This possibly interesting result reinforces the need to greatly expand the sample of time-delay lenses, e.g., with the successful implementation of the Dark Energy Survey, the VST ATLAS survey, and the Large Synoptic Survey Telescope. In anticipation of a greatly expanded catalog of time-delay lenses identified with these surveys, we have produced synthetic samples to estimate how large they would have to be in order to rule out either model at a ∼99.7% confidence level. We find that if the real cosmology is ΛCDM, a sample of ∼150 time-delay lenses would be sufficient to rule out Rh = ct at this level of accuracy, while ∼1000 time-delay lenses would be required to rule out ΛCDM if the real universe is instead Rh = ct. This difference in required sample size reflects the greater number of free parameters available to fit the data with ΛCDM. [ABSTRACT FROM AUTHOR]

The observed spectral lags of gamma-ray bursts (GRBs) have been widely used to explore possible violations of Lorentz invariance. However, these studies were generally performed by concentrating on the rough time lag of a single highest-energy photon and ignoring the intrinsic time lag at the source. A new way to test nonbirefringent Lorentz-violating effects has been proposed by analyzing the multi-photon spectral-lag behavior of a GRB that displays a positive-to-negative transition. This method gives both a plausible description of the intrinsic energy-dependent time lag and comparatively robust constraints on Lorentz-violating effects. In this work, we conduct a systematic search for Lorentz-violating photon dispersion from the spectral-lag transition features of 32 GRBs. By fitting the spectral-lag data of these 32 GRBs, we place constraints on a variety of isotropic and anisotropic Lorentz-violating coefficients with mass dimension d = 6 and 8. While our dispersion constraints are not competitive with existing bounds, they have the promise to complement the full coefficient space. [ABSTRACT FROM AUTHOR]

We update gamma-ray burst (GRB) luminosity relations among certain spectral and light-curve features with 139 GRBs. The distance modulus of 82 GRBs at z>1.4 can be calibrated with the sample at z≤1.4 by using the cubic spline interpolation method from the Union2.1 Type Ia supernovae (SNe Ia) set. We investigate the joint constraints on the Cardassian expansion model and dark energy with 580 Union2.1 SNe Ia sample (z<1.4) and 82 calibrated GRBs’ data (1.4

We extend the standard model of forward–reverse shock (FS–RS) for gamma-ray burst (GRB) afterglow to more general cases. On one hand, we derive the analytical solution to the hydrodynamics of the shocks in two limiting cases, i.e. an ultrarelativistic reverse shock case and a Newtonian reverse shock case. Based on the asymptotic solutions in these two limiting cases, we constitute a semi-analytical solution for the hydrodynamics of the shocks in the generic case, covering the mildly relativistic reverse shock case. On the other hand, we derive the evolution of the system taking into account the condition of energy conservation which is not satisfied in the standard FS–RS model. A generic solution of semi-analytical expressions is also given. In both the extended standard FS–RS model (satisfying pressure balance condition) and the model satisfying energy conservation, we find that the results in the ultrarelativistic reverse shock case and in the early stage of the Newtonian reverse shock case are different from those in the standard FS–RS model by only a factor that close to one while the same initial conditions adopted. However, the asymptotic solutions in the limiting cases are not good approximations to those in the intermediate case. Our semi-analytical results agree well with the numerical results for a large range of model parameters, and hence can be easily employed to diagnose the physical quantities of the GRB shell and circumburst environment. [ABSTRACT FROM AUTHOR]

Electrochemical CO2‐to‐CO conversion provides a possible way to address problems associated with the greenhouse effect; however, developing low‐cost electrocatalysts to mediate high‐efficiency CO2 reduction remains a challenge on account of the limited understanding of the nature of the real active sites. Herein, we reveal the Znδ+ metalloid sites as the real active sites of stable nonstoichiometric ZnOx structure derived from Zn2P2O7 through operando X‐ray absorption fine structure analysis in conjunction with evolutionary‐algorithm‐based global optimization. Furthermore, theoretical and experimental results demonstrated that Znδ+ metalloid active sites could facilitate the activation of CO2 and the hydrogenation of *CO2, thus accelerating the CO2‐to‐CO conversion. Our work establishes a critical fundamental understanding of the origin of the real active center in the zinc‐based electrocatalysts for CO2 reduction reaction. [ABSTRACT FROM AUTHOR]

Electrochemical CO2‐to‐CO conversion provides a possible way to address problems associated with the greenhouse effect; however, developing low‐cost electrocatalysts to mediate high‐efficiency CO2 reduction remains a challenge on account of the limited understanding of the nature of the real active sites. Herein, we reveal the Znδ+ metalloid sites as the real active sites of stable nonstoichiometric ZnOx structure derived from Zn2P2O7 through operando X‐ray absorption fine structure analysis in conjunction with evolutionary‐algorithm‐based global optimization. Furthermore, theoretical and experimental results demonstrated that Znδ+ metalloid active sites could facilitate the activation of CO2 and the hydrogenation of *CO2, thus accelerating the CO2‐to‐CO conversion. Our work establishes a critical fundamental understanding of the origin of the real active center in the zinc‐based electrocatalysts for CO2 reduction reaction. [ABSTRACT FROM AUTHOR]

Highlights: [•] BjC-P is responsive to both fungus and fungal elicitor Hexa-N-Acetyl-Chitohexaose. [•] Only one of the six W-box-like elements is necessary for the fungus-inductivity. [•] The W-box-like-4 needs coupled with a 73-bp region to confer full inductivity. [•] The T/G box in the 73-bp region is not crucial for the fungus-inductivity. [•] Transient-expression assay was consistent with transgenic Arabidopsis analysis. [ABSTRACT FROM AUTHOR]

The esterification kinetics of concentrated lactic acid with methanol catalysed by ion-exchange resins are presented. The effects of catalyst type, size and loading, initial ratio of reactants, and temperature on the reaction kinetics were evaluated. Reaction rate data were correlated with a kinetic model based on pseudo-homogeneous catalysis. The activation energy of the reaction was found to be 48.88 kJ mol-1 in the presence of D001. A kinetic equation is developed describing the reaction catalysed by a cation exchange resin developed. [ABSTRACT FROM AUTHOR]

Abstract: In this study, we report the role of integrin α5 in promoting melanoma metastasis. The α5 expression was remarkably elevated in highly metastatic B16F10 melanoma cells compared to lowly metastatic B16F1 cells, whereas no significant changes were detected in those of integrin α4, αv, and β1 subunits. Neutralization of α5 with anti-α5 antibody significantly suppressed the potential of B16F10 cells for pulmonary metastasis in mice and inhibited cell adhesion or spreading to fibronectin in vitro. Furthermore, loss of the interaction between α5 and fibronectin diminished cell survival and induced apoptosis in B16F10 cells. Above results provide clear evidence that integrin α5 is positively correlated with melanoma metastasis and might be an anti-melanoma target. [Copyright &y& Elsevier]

The spectral lags of gamma-ray bursts (GRBs) have been viewed as the most promising probes of the possible violations of Lorentz invariance (LIV). However, these constraints usually depend on the assumption of the unknown intrinsic time lag in different energy bands and the use of a single highest-energy photon. A new approach to test the LIV effects has been proposed by directly fitting the spectral-lag behavior of a GRB with a well-defined transition from positive lags to negative lags. This method simultaneously provides a reasonable formulation of the intrinsic time lag and robust lower limits on the quantum-gravity energy scales (EQG). In this work, we perform a global fitting to the spectral-lag data of GRB 190114C by considering the possible LIV effects based on a Bayesian approach. We then derive limits on EQG and the coefficients of the standard model extension. The Bayes factor output in our analysis shows very strong evidence for the spectral-lag transition in GRB 190114C. Our constraints on a variety of isotropic and anisotropic coefficients for LIV are somewhat weaker than existing bounds, but they can be viewed as comparatively robust and have the promise to complement existing LIV constraints. The observations of GRBs with higher-energy emissions and higher temporal resolutions will contribute to a better formulation of the intrinsic time lag and more rigorous LIV constraints in the dispersive photon sector. [ABSTRACT FROM AUTHOR]

We study the luminosity function and formation rate of long gamma-ray bursts (GRBs) by using a maximum likelihood method. This is the first time this method is applied to a well-defined sample of GRBs that is complete in redshift. The sample is composed of 99 bursts detected by the Swift satellite, 81 of them with measured redshift and luminosity for a completeness level of |$82\, {\rm per\, cent}$|⁠. We confirm that a strong redshift evolution in luminosity (with an evolution index of |$\delta =2.22^{+0.32}_{-0.31}$|⁠) or in density (⁠|$\delta =1.92^{+0.20}_{-0.21}$|⁠) is needed in order to reproduce the observations well. But since the predicted redshift and luminosity distributions in the two scenarios are very similar, it is difficult to distinguish between these two kinds of evolutions only on the basis of the current sample. Furthermore, we also consider an empirical density case in which the GRB rate density is directly described as a broken power-law function and the luminosity function is taken to be non-evolving. In this case, we find that the GRB formation rate rises like |$(1+z)^{3.85^{+0.48}_{-0.45}}$| for |$z\lesssim 2$| and is proportional to |$(1+z)^{-1.07^{+0.98}_{-1.12}}$| for |$z\gtrsim 2$|⁠. The local GRB rate is |$1.49^{+0.63}_{-0.64}$|  Gpc−3 yr−1. The GRB rate may be consistent with the cosmic star formation rate (SFR) at |$z\lesssim 2$|⁠ , but shows an enhancement compared to the SFR at |$z\gtrsim 2$|⁠. [ABSTRACT FROM AUTHOR]

Postoperative pain is a common form of acute pain that, if not managed effectively, can become chronic pain. Evidence has shown that glia, especially microglia, mediate neuroinflammation, which plays a vital role in pain sensitization. Moreover, toll-like receptor 4 (TLR4), the tumor necrosis factor receptor (TNF-R), the interleukin-1 receptor (IL-1R), and the interleukin-6 receptor (IL-6R) have been considered key components in central pain sensitization and neuroinflammation. Therefore, we hypothesized that activation of the body’s endogenous “immune brakes” will inhibit these receptors and achieve inflammation tolerance as well as relieve postoperative pain. After searching for potential candidates to serve as this immune brake, we identified and focused on the suppressor of cytokine signaling 3 (SOCS3) gene. To regulate SOCS3 expression, we used paeoniflorin to induce heat shock protein 70 (HSP70)/TLR4 signaling. We found that paeoniflorin significantly induced SOCS3 expression both in vitro and in vivo and promoted the efflux of HSP70 from the cytoplasm to the extracellular environment. Furthermore, paeoniflorin markedly attenuated incision-induced mechanical allodynia, and this effect was abolished by small interfering RNAs targeting SOCS3. These findings demonstrated an effective and safe strategy to alleviate postoperative pain. [ABSTRACT FROM AUTHOR]

We present a detailed report of the connection between long-duration gamma-ray bursts (GRBs) and their accompanying supernovae (SNe). The discussion presented here places emphasis on how observations, and the modelling of observations, have constrained what we know about GRB-SNe. We discuss their photometric and spectroscopic properties, their role as cosmological probes, including their measured luminosity–decline relationships, and how they can be used to measure the Hubble constant. We present a statistical summary of their bolometric properties and use this to determine the properties of the “average” GRB-SN. We discuss their geometry and consider the various physical processes that are thought to power the luminosity of GRB-SNe and whether differences exist between GRB-SNe and the SNe associated with ultra-long-duration GRBs. We discuss how observations of their environments further constrain the physical properties of their progenitor stars and give a brief overview of the current theoretical paradigms of their central engines. We then present an overview of the radioactively powered transients that have been photometrically associated with short-duration GRBs, and we conclude by discussing what additional research is needed to further our understanding of GRB-SNe, in particular the role of binary-formation channels and the connection of GRB-SNe with superluminous SNe. [ABSTRACT FROM AUTHOR]

Phosphatase of regenerating liver-3 (PRL-3) has been reported to have a critical role in metastatic progression of cancers. Here, we investigate how PRL-3 increases the malignant degree of melanoma cells. The expression of PRL-3 increased gradually during the malignant progression of melanoma. The phosphorylation of Akt was elevated in highly malignant melanoma cells, which was accompanied by a decrease in nuclear phosphatase and tensin homolog (PTEN). The phosphorylation of NHERF1 in the serine site was regulated by PRL-3 and showed cytoplasmic translocation upon dephosphorylation, which resulted in a decrease in nuclear PTEN. The co-translocation of NHERF1 and PTEN from the nucleus to the cytoplasm was observed during the malignant progression of melanoma cells. Tumor growth was inhibited significantly, and the survival was prolonged upon knockdown of cytoplasmic NHERF1 in B16BL6 cells prior to the inoculation into mice. Taken together, to our knowledge previously unreported, we have identified NHERF1 as a potential substrate of PRL-3. Its phosphorylation status as well as its change in cellular localization and association with PTEN correlated with the malignant progression of melanoma. Our data provide an explanation for how PRL-3 promotes the malignant progression of melanoma, as well as a diagnostic marker or therapeutic target for malignant melanoma. [ABSTRACT FROM AUTHOR]

The giant X-ray bump of GRB 121027A observed by Swift is different from the typical X-ray flares in gamma-ray bursts. The observed structural variability in the rise and decay phases of the bump has four components. Of these four components, only the data in the bump from about 5300 to about 6100 s is of good enough quality to be analysed using the stepwise filter correlation method. A $86^{+5.9}_{-9.4} \rm s$ periodic oscillation is postulated, which is confirmed by the Lomb–Scargle method. A jet precession model is proposed to account for this variability. [ABSTRACT FROM AUTHOR]

Abstract: Gamma-ray bursts are most luminous explosions in the universe. Their ejecta are believed to move towards Earth with a relativistic speed. The interaction between this “relativistic jet” and a circumburst medium drives a pair of (forward and reverse) shocks. The electrons accelerated in these shocks radiate synchrotron emission to power the broad-band afterglow of GRBs. The external shock theory is an elegant theory, since it invokes a limit number of model parameters, and has well predicted spectral and temporal properties. On the other hand, depending on many factors (e.g. the energy content, ambient density profile, collimation of the ejecta, forward vs. reverse shock dynamics, and synchrotron spectral regimes), there is a wide variety of the models. These models have distinct predictions on the afterglow decaying indices, the spectral indices, and the relations between them (the so-called “closure relations”), which have been widely used to interpret the rich multi-wavelength afterglow observations. This review article provides a complete reference of all the analytical synchrotron external shock afterglow models by deriving the temporal and spectral indices of all the models in all spectral regimes, including some regimes that have not been published before. The review article is designated to serve as a useful tool for afterglow observers to quickly identify relevant models to interpret their data. The limitations of the analytical models are reviewed, with a list of situations summarized when numerical treatments are needed. [Copyright &y& Elsevier]

We continue our systematic statistical study of various components of gamma-ray burst (GRB) optical light curves. We decompose the early onset bump and the late re-brightening bump with empirical fits and analyze their statistical properties. Among the 146 GRBs that have well-sampled optical light curves, the onset and re-brightening bumps are observed in 38 and 26 GRBs, respectively. It is found that the typical rising and decaying slopes for both the onset and re-brightening bumps are ~1.5 and ~-1.15, respectively. No early onset bumps in the X-ray band are detected to be associated with the optical onset bumps, while an X-ray re-brightening bump is detected for half of the re-brightening optical bumps. The peak luminosity is anti-correlated with the peak time Lp α t -1.81±0.32 p for the onset bumps and Lp ℵ t -0.83±0.17 p for the re-brightening bumps. Both Lp and the isotropic energy release of the onset bumps are correlated with Eγ,iso, whereas no similar correlation is found for the re-brightening bumps. These results suggest that the afterglow onset bumps are likely due to the deceleration of the GRB fireballs. Taking the onset bumps as probes for the properties of the fireballs and their ambient medium, we find that the typical power-law index of the relativistic electrons is 2.5 and the medium density profile behaves as n ℵ r -1 within the framework of the synchrotron external shock models. With the medium density profile obtained from our analysis, we also confirm the correlation between the initial Lorentz factor (Γ0) and Eiso,γ in our previous work. The jet component that produces the re-brightening bump seems to be on-axis and independent of the prompt emission jet component. Its typical kinetic energy budget would be about one order of magnitude larger than the prompt emission component, but with a lower Γ0, typically several tens. [ABSTRACT FROM AUTHOR]

Abstract: In the present paper, we examined the effects of a natural cyclopeptide RA-V on human breast cancer cells and the underlying mechanisms. RA-V significantly inhibited the growth of human breast cancer MCF-7, MDA-MB-231 cells and murine breast cancer 4T1 cells. In addition, RA-V triggered mitochondrial apoptotic pathway which was indicated by the loss of mitochondrial membrane potential, the release of cytochrome c, and the activation of caspase cascade. Further study showed that RA-V dramatically inhibited phosphorylation of AKT and 3-phosphoinositide dependent protein kinase 1 (PDK1) in MCF-7 cells. Moreover, RA-V disrupted the interaction between PDK1 and AKT in MCF-7 cells. Furthermore, RA-V-induced apoptosis could be enhanced by phosphatidylinositol 3-kinase inhibitor or attenuated by over-expression of AKT in all the three kinds of breast cancer cells. Taken together, this study shows that RA-V, which can induce mitochondria-mediated apoptosis, exerts strong anti-tumor activity against human breast cancer. The underlying anti-cancer mechanism of RA-V is related to the blockage of the interaction between PDK1 and AKT. [Copyright &y& Elsevier]

Abstract: Dysregulation of signal transducer and activator of transcription (STAT) signaling is usually associated with intricate immune diseases and rebuilding the balance of STAT1 and STAT3 signaling is being explored as a useful approach for the treatment of these diseases. However, few chemicals have been reported to rebuild the balance of these two signalings for immune hepatitis therapy. In the present study, we found that fusaruside, a new kind of cerebroside isolated from an endophytic fungus Fusarium sp. IFB-121 in Quercus variabilis, significantly ameliorated concanavalin A (Con A)-induced T-cell-mediated fulminant hepatitis in mice, which was closely associated with the improvement of histopathological parameters, inhibition of activation of liver CD4+ T cells and NKT cells, regulation of balance of Th1/Th2/Th17/Treg cytokines and protection of hepatocyte from apoptosis. Moreover, T-cell proliferation and activation was also notably inhibited by fusaruside in vitro. Furthermore, the protective effect of fusaruside was attributable to a novel regulatory mechanism through down-regulating STAT1 activation and T-bet expression in liver CD4+ T cells and up-regulating STAT3 activation and Bcl-XL expression in hepatocytes. In conclusion, fusaruside exhibited its capability against T-cell-mediated liver injury in vivo, through rebuilding the balance of STAT1 and STAT3 signalings. These results suggest that fusaruside is potentially useful for the treatment of T-cell-mediated human liver disorders. [Copyright &y& Elsevier]

Abstract: Ethnopharmacological relevance: In traditional Chinese medicines, Cortex Dictamni is prescribed for the treatment of a variety of inflammatory diseases such as acute rheumatoid arthritis, skin inflammation and jaundice. Aim of the study: This study was designed to investigate the effect of ethanol extract of Cortex Dictamni on treatment of hepatic fibrosis and its possible mechanisms. Materials and methods: The in vivo effect of Cortex Dictamni extract (CDE) was evaluated by measuring histological changes and collagen content in CCl4-indcued hepatic fibrosis mice. Viability, apoptosis and protein expression of hepatic stellate cells (HSC) were analyzed by MTT, Annexin V staining and Western blot respectively. Results: CDE alleviated CCl4-induced hepatic fibrosis in mice and showed a much stronger inhibition of cell viability in activated HSC cell line HSC-T6 than that in normal hepatocyte L02 cells. Furthermore, CDE induced apoptosis of HSC-T6 cells associated with increased expressions of cleaved PARP and cleaved caspase-3. Interestingly, CDE activated STAT1 in HSC-T6 cells and the effect of CDE on apoptosis of HSC-T6 cells could be neutralized using JAK/STAT1 signaling inhibitor AG490. Conclusions: These findings suggest that CDE possesses anti-fibrosis activity with selectively induction of activated HSC apoptosis via activating STAT1, which might be a novel strategy for hepatic fibrosis therapy. [Copyright &y& Elsevier]

Abstract: Regulation of signal transducer and activator of transcription (STAT) 1 signaling is being explored as a new approach to the treatment of inflammatory bowel diseases. However, few chemicals have been reported to inhibit IFN-γ/STAT1 signaling for Crohn''s disease therapy. In the present study, we found that cirsilineol, a small natural compound isolated from Artemisia vestita, significantly ameliorated trinitro-benzene sulfonic acid (TNBS)-induced T-cell-mediated experimental colitis in mice, which was closely associated with reduced autoreactive T-cell proliferation and activation. Moreover, the regulatory action of pro-inflammatory and anti-inflammatory cytokine by cirsilineol treatment was found to decrease the activity of effector Th1 cells but increase the activity of regulatory T cells as characterized by down-regulation of IFN-γ and corresponding up-regulation of IL-10 and TGF-β. The therapeutic effect of cirsilineol was attributable to a novel regulatory mechanism with selective inhibiting IFN-γ signaling in colonic lamina propria CD4+ T cells, which was mediated through down-regulating STAT1 activation and T-bet expression. Furthermore, cirsilineol was found to down-regulate the activation of JAK2, a critical kinase for IFN-γ/STAT1 signaling, and abrogate the expression of T-bet, resulting in markedly decreased proliferation and activation of T cells in vitro. Importantly, the inhibition of IFN-γ/STAT1 signaling by cirsilineol was reversible in the presence of high level of IFN-γ. These results strongly suggest that cirsilineol might be potentially useful for treating T-cell-mediated human inflammatory bowel diseases. [Copyright &y& Elsevier]

Abstract: Selectively inducing apoptosis of activated T cells is essential for the clearance of pathogenic injurious cells and subsequent efficient resolution of inflammation. However, few chemicals have been reported to trigger apoptosis of activated T cells in the treatment of hepatitis without affecting quiescent T cells. In the present study, we found that fraxinellone, a small natural compound isolated from the root bark of Dictamnus dasycarpus, selectively facilitated apoptosis of concanavalin A (Con A)-activated CD4+ T cells rather than those non-activated, by disrupting the mitochondrial transmembrane potential, decreasing the ratio of Bcl-2/Bax, and increasing cytochrome c release from the mitochondria to the cytosol. The enhancement in Fas expression and caspase-8 activity, truncation of Bid, and down-regulation of anti-apoptotic cellular FLICE-inhibitory protein expression by fraxinellone also suggested the participation of an extrinsic apoptosis pathway. Furthermore, fraxinellone significantly alleviated Con A-induced T-cell-dependent hepatitis in mice, which was closely associated with reduced serum transaminases, pro-inflammatory cytokines, and pathologic parameters. Consistent with the in vitro results, fraxinellone dramatically induced apoptosis of activated peripheral CD4+ T cells in vivo, consequently resulting in less CD4+ T-cell activation and infiltration to the liver. These results strongly suggest fraxinellone might be a potential leading compound useful in treating T-cell-mediated liver disorders in humans. [Copyright &y& Elsevier]

We present a spectral analysis for a sample of redshift-known gamma-ray bursts (GRBs) observed with Fermi/GBM. Together with the results derived from our systematical spectral energy distribution modeling with the leptonic models for a Fermi/LAT blazar sample, we compare the distributions of the GRBs and the blazars by plotting the synchrotron peak luminosity (Ls) and the corresponding peak photon energy Es of blazars in the Lp-Ep-plane of GRBs, where Lp and Ep are the peak luminosity and peak photon energy of the GRB time-integrated νfν spectrum, respectively. The GRBs are in the high-Lp, high-Ep corner of the plane and a tight Lp-Ep relation is found, i.e., . Both flat spectrum radio quasars (FSRQs) and low-synchrotron peaking BL Lac objects (LBLs) are clustered in the low-Ep, low-Lp corner. Intermediate- and high-synchrotron peaking BL Lac objects (IBLs and HBLs) have Es ∼ 2 × 10–3-102 keV and Ls ∼ 1044-1047 erg s–1, but no dependence of Ls on Es is found. We show that the tight Lp-Ep relation of GRBs is potentially explained with the synchrotron radiation of fast-cooling electrons in a highly magnetized ejecta, and the weak anti-correlation of Ls-Es for FSRQs and LBLs may be attributed to synchrotron radiation of slow-cooling electrons in a moderately magnetized ejecta. The distributions of IBLs and HBLs in the Lp-Ep-plane may be interpreted with synchrotron radiation of fast-cooling electrons in a matter-dominated ejecta. These results may present a unified picture for the radiation physics of relativistic jets in GRBs and blazars within the framework of the leptonic synchrotron radiation models. [ABSTRACT FROM AUTHOR]