Zebrafish spop promotes ubiquitination and degradation of mavs to suppress antiviral response via the lysosomal pathway

Retinoic acid-inducible gene I (RIG-I)-like receptors (RLRs) signaling pathways are required to be tightly controlled to initiate host innate immune responses. Fish mitochondrial antiviral signaling (mavs) is a key determinant in the RLR pathway, and its ubiquitination is associated with mavs activation. Here, we identified the zebrafish E3 ubiquitin ligase Speckle-type BTB-POZ protein (spop) negatively regulates mavs-mediated the type I interferon (IFN) responses. Consistently, overexpression of zebrafish spop repressed the activity of IFN promoter and reduced host ifn transcription, whereas knockdown spop by small interfering RNA (siRNA) transfection had the opposite effects. Accordingly, overexpression of spop dampened the cellular antiviral responses triggered by spring viremia of carp virus (SVCV). A functional domain assay revealed that the N-terminal substrate-binding MATH domain regions of spop were necessary for IFN suppression. Further assays indicated that spop interacts with mavs through the C-terminal transmembrane (TM) domain of mavs. Moreover, zebrafish spop selectively promotes K48-linked polyubiquitination and degradation of mavs through the lysosomal pathway to suppress IFN expression. Our findings unearth a post-translational mechanism by which mavs is regulated and reveal a role for spop in inhibiting antiviral innate responses.

Tunable, pulsed multiline intracavity optical parametric oscillator using two-dimensional MgO: periodically poled lithium niobate-aperiodically poled lithium niobate

We report a tunable, pulsed multiline intracavity optical parametric oscillator (IOPO) realized in an Nd:YVO4 laser using a two-dimensionally domain engineered MgO:LiNbO3 as simultaneously an electro-optic Bragg Q switch and a multichannel optical parametric downconverter. The MgO:LiNbO3 was periodically and aperiodically poled along the crystallographic y and x axes, respectively, to simultaneously satisfy the phase-matching conditions required by the two quasi-phase-matching devices. When Q switched by 1 kHz, 300 V pulses, three signal lines at 1518, 1526, and 1534 nm were simultaneously generated, each with a peak power of ∼1  kW from the IOPO at 8.3 W diode power at 50°C. Spectral tuning of the three-line IOPO with temperature was demonstrated.

Growth of magneto-optically active (Zn,Mn)Se nanowires

We describe the growth of Zn(1-x)Mn(x)Se nanowires in ultrahigh vacuum seeded by Au nanodroplets. Electron microscopy reveals the formation of single-crystal c-axis wurtzite nanowires (typically 1-3 microm long) with Mn concentrations up to x approximately 0.6, accompanied by a dense horizontal undergrowth of shorter, crooked nanowires. Magnetophotoluminescence measurements show evidence for sp-d exchange effects in a reduced symmetry environment. We find that the optical emission is surprisingly dominated by the undergrowth of crooked nanowires.

Effects of Matrine on proliferation and differentiation in K-562 cells

We investigated the effects of Matrine on proliferation by trypan blue exclusion and differentiation by benzidine staining positive cells in K-562 cells, assayed the telomerase activity using PCR-ELISA assay, analyzed cell cycle by fluorescence-activated cell sorter analysis of the DNA content, and also determined the gene expression level of c-myc, N-ras and p53 by northern blot and dot blot analysis. The results showed that with the addition of 0.1 mg/ml Matrine, cell growth was inhibited significantly by 4 days, benizidine-positive cells rose from 1% to 2% in control cells to 15% in treated cells on day 5; treatment of K-562 cells with 0.1 mg/ml Matrine for 5 days resulted in a marked inhibition in telomerase activity, in a manner that correlated with the extent of differentiation; after exposure to Matrine for 72 h, 64.6% cells were arrested in the G1-phase of the cell cycle, the fraction of cells in S-phase had decreased from 56.9% in control cells to 24.4% in differentiated cells, and the levels of N-ras and p53 mRNA were remarkably increased for 24 and 48 h, respectively, c-myc mRNA expression level declined for 24 h and was inhibited significantly for 48 h. Our study confirmed that Matrine plays a significant effect on the inhibition of proliferation cells and inducing differentiation in K-562 cells.

[Analysis of headspace constituents of Gardenia flower by GC/MS with solid-phase microextraction and dynamic headspace sampling]

The headspace constituents of fresh Gardenia flower were investigated by GC/MS. The headspace volatiles were sampled by solid-phase microextraction (SPME) and dynamic headspace sampling (DHS). SPME sampling was conducted with 100 microns PDMS fiber at 28 degrees C for 60 min. In DHS sampling, purified nitrogen was used as purging gas with a flow rate at 80 mL/min for 120 min. Tenax GR(20 mesh-40 mesh) was used as adsorbent and the volatiles were eluted by ether, and concentrated to 0.5 mL for GC/MS analysis. A Supelco-wax capillary column (30 m x 0.25 mm i.d. x 0.25 micron df) was employed in GC/MS analysis. Initial oven temperature was kept at 45 degrees C for 2 min, then raised to 250 degrees C at 4 degrees C/min, and kept at 250 degrees C for 10 min. According to SPME-GC/MS analysis, the main compounds in headspace of fresh Gardenia flower included farnesene(64.86%), cis-ocimene(29.33%), linalool(2.74%), cis-3-hexenyl tiglate(1.34%), methyl benzoate(0.25%). Results obtained from SPME and DHS sampling were also compared. In this study, SPME afforded a simpler and more sensitive sampling method, and much more accurate information about headspace volatiles of Gardenia flower.

[A study on the chemical components of essential oil of oak moss concrete by gas chromatography/mass spectrometry]

The essential oil of oak moss concrete was extracted by volatile oil content equipment. The chemical compositions and their relative contents were analyzed by GC and GC/MS. A Supelco-5 fused silica capillary column (30 m x 0.32 mm i.d.; 0.25 micron thickness) and a flame ionization detector (FID) were employed in GC analysis. The temperature program included temperature increase of 4 degrees C/min from 50 degrees C to 250 degrees C, and a 10 min isothermal period at 250 degrees C. Mass spectra were obtained by electron impact at 70 eV and a source temperature of 170 degrees C. Twenty-four volatile compounds of oak mass concrete were identified, which comprised more than 83% of volatile fraction. The major components were diethyl phthalate, alpha-terpineol, cedrane and linalool.

[Determination of beta-carotene in tobacco by HPTLC]

This paper reports the high performance thin-layer chromatography (HPTLC) determination of beta-carotene in tobacco. The developer used was V(benzene):V(acetone) = 4:1. The detection wavelength was 450 nm. The linear range and the detectable limit of the method were 50 ng-0.5 microgram and 20 ng per spot of beta-carotene respectively. The method has been proved to be simple, sensitive, accurate and reproducible.

A comprehensive dynamical model of pulsatile secretion of the hypothalamo-pituitary-gonadal axis in man

We proposed a comprehensive dynamical model for the hormone secretion of the hypothalamo-pituitary-gonadal axis in man. This model is comprehensive and more reasonable than any previous model. A large number of deductions of this model agree well with experimental results.

An improved mathematical model of hormone secretion in the hypothalamo-pituitary-gonadal axis in man

We propose an improved mathematical model for the secretion in the hypothalamo-pituitary-gonadal axis. We think this model is more reasonable than any previous one and can interpret a large number of experimental facts.