Altered expression of circadian clock gene, mPer1, in mouse brain and kidney under morphine dependence and withdrawal

Every physiological function in the human body exhibits some form of circadian rhythmicity. Under pathological conditions, however, circadian rhythmicity may be dusrupted. Patients infected with HIV or addicted to drugs of abuse often suffer from sleep disorders and altered circadian rhythms. Early studies in Drosophila suggested that drug seeking behavior might be related to the expression of certain circadian clock genes. Our previous research showed that conditioned place preference with morphine treatment was altered in mice lacking the Period-1 (mPer1) circadian clock gene. Thus, we sought to investigate whether morphine treatment could alter the expression of mPer1, especially in brain regions outside the SCN and in peripheral tissues. Our results using Western blot analysis showed that the mPER1 immunoreactivity exhibited a strong circadian rhythm in the brains of the control (Con), morphine-dependent (MD), and morphine-withdrawal (MW) mice. However, the phase of the circadian rhythm of mPER1 expression in the brains of MD mice significantly differed from that of the Con mice (p < 0.05). In contrast to mPER1 expression in the brain, the circadian rhythm of mPER1 immunoreactivity in the kidneys was abolished after morphine administration, whereas the Con mice maintained robust circadian rhythmicity of mPER1 in the kidney. Therefore, the effect of morphine on the circadian clock gene mPer1 may vary among different organs, resulting in desynchronization of circadian function between the SCN and peripheral organs. Originally published Journal of Circadian Rhythms, Vol. 4, No. 9, Aug 2006

Biogeography and Virulence of Staphylococcus aureus

Staphylococcus aureus is commonly carried asymptomatically in the human anterior nares and occasionally enters the bloodstream to cause invasive disease. Much of the global diversity of S. aureus remains uncharacterised, and is not clear how disease propensity varies between strains, and between host populations.We compared 147 isolates recovered from five kindergartens in Chengdu, China, with 51 isolates contemporaneously recovered from cases of pediatric infection from the main hospital serving this community. The samples were characterised by MLST, the presence/absence of PVL, and antibiotic resistance profiling.Genotype frequencies within individual kindergartens differ, but the sample recovered from cases of disease shows a general enrichment of certain MLST genotypes and PVL positive isolates. Genotypes under-represented in the disease sample tend to correspond to a single sequence cluster, and this cluster is more common in China than in other parts of the world.Virulence propensity likely reflects a synergy between variation in the core genome (MLST) and accessory genome (PVL). By combining evidence form biogeography and virulence we demonstrate the existence of a "native" clade in West China which has lowered virulence, possibility due to acquired host immunity

Hepatitis C Virus Core-Derived Peptides Inhibit Genotype 1b Viral Genome Replication via Interaction with DDX3X

The protein DDX3X is a DEAD-box RNA helicase that is essential for the hepatitis C virus (HCV) life cycle. The HCV core protein has been shown to bind to DDX3X both in vitro and in vivo. However, the specific interactions between these two proteins and the functional importance of these interactions for the HCV viral life cycle remain unclear. We show that amino acids 16–36 near the N-terminus of the HCV core protein interact specifically with DDX3X both in vitro and in vivo. Replication of HCV replicon NNeo/C-5B RNA (genotype 1b) is significantly suppressed in HuH-7-derived cells expressing green fluorescent protein (GFP) fusions to HCV core protein residues 16–36, but not by GFP fusions to core protein residues 16–35 or 16–34. Notably, the inhibition of HCV replication due to expression of the GFP fusion to HCV core protein residues 16–36 can be reversed by overexpression of DDX3X. These results suggest that the protein interface on DDX3X that binds the HCV core protein is important for replicon maintenance. However, infection of HuH-7 cells by HCV viruses of genotype 2a (JFH1) was not affected by expression of the GFP fusion protein. These results suggest that the role of DDX3X in HCV infection involves aspects of the viral life cycle that vary in importance between HCV genotypes

Sensitivity Analysis of Influencing Factors of Underground Civil Air Defense Construction Vibration under Vehicle Load

Grey correlation theory is an uncertainty analysis method, which can find the relevance of various factors studied through certain data processing in incomplete information and find the main influencing factors. In order to study the influence of vehicle load on the vibration of underground civil air defense construction, taking the civil air defense construction at the intersection of Zhongzhou Middle Road and Shachang South Road in Luoyang as the study subject, based on the field measured data, and using ANSYS to expand the working conditions, this paper studies the influence of such factors as elastic modulus of concrete, thickness of overburden layer, density of soil layer, elastic modulus of soil layer, vehicle speed, and vehicle mass on the vibration of the civil air defense construction through the grey correlation sensitivity analysis method. The field measurement and numerical simulation results show that the displacement, velocity, and acceleration values decrease gradually from the mid−span position of the roof to the wall. Displacement, velocity, and acceleration are important indexes for evaluating vibration. The grey correlation degree of the influencing factors of displacement and velocity from large to small is density of soil layer, vehicle mass, vehicle speed, elastic modulus of concrete, elastic modulus of soil layer, and thickness of overburden layer. The grey correlation degree of the influencing factors of acceleration from large to small is vehicle mass, layer of density of soil layer, vehicle speed, elastic modulus of concrete, elastic modulus of soil layer, and thickness of overburden layer. The grey correlation degree of soil layer density, vehicle mass and vehicle speed to displacement, velocity, and acceleration is 0.7951–0.9993, which indicates that their influence is significant. This study can provide reference for the design and construction of similar civil air defense constructions

Molecular Characterization of the Minimal Replicon and the Unidirectional Theta Replication of pSCM201 in Extremely Halophilic Archaea

A 3,463-bp plasmid, pSCM201, was isolated from a halophilic archaeon, Haloarcula sp. strain AS7094. The minimal replicon that is essential and sufficient for autonomous replication and stable maintenance in Haloarcula hispanica was determined by deletion analysis of the plasmid. This minimal replicon (∼1.8 kb) consisted of only two functionally related segments: (i) a putative origin (ori201) containing an AT-rich region and sets of repeats and (ii) an adjacent gene encoding a putative replication initiation protein (Rep201). Electron microscopic observation and Southern blotting analysis demonstrated that pSCM201 replicates via a theta mechanism. Precise mapping of the putative origin suggested that the replication initiated from a fixed site close to the AT-rich region and proceeded unidirectionally toward the downstream rep201 gene, which was further confirmed by electron microscopic analysis of the ClaI-digested replication intermediates. To our knowledge, this is the first unidirectional theta replication plasmid experimentally identified in the domain of archaea. It provides a novel plasmid system to conduct research on archaeal DNA replication

Study on Blasting Vibration Control of Brick-Concrete Structure under Subway Tunnel

In order to study the impact of the blasting vibration of subway tunnels on adjacent buildings, taking the tunnel mining method construction of the section between Zhifang Street Station and Metro Town Station of Wuhan Metro Line 27 as the engineering background, the blasting scheme is optimized by reducing the maximum single section charge, multi-section and densifying the surrounding holes. The HHT method and wavelet analysis are used to evaluate the advantages and disadvantages of the optimization scheme from the perspective of energy. The results show that the peak velocity of the blasting vibration is significantly reduced and the frequency is significantly increased after the blasting scheme is optimized. After the blasting scheme is optimized, when the working face is directly below the external wall of the building, the peak vibration velocity is the largest; from the back of the working face to the front of the working face, the peak velocity of the surface particle vibration first increases and then decreases. The frequency band of the optimized blasting vibration signal energy distribution is wider and the energy is more dispersed. This study can provide some practical experience for the design and construction of similar projects

Characterization of Antifungal Lipopeptide Biosurfactants Produced by Marine Bacterium <i>Bacillus</i> sp. CS30

This study was initiated to screen for marine bacterial agents to biocontrol Magnaporthe grisea, a serious fungal pathogen of cereal crops. A bacterial strain, isolated from the cold seep in deep sea, exhibited strong growth inhibition against M. grisea, and the strain was identified and designated as Bacillus sp. CS30. The corresponding antifungal agents were purified by acidic precipitation, sequential methanol extraction, Sephadex LH-20 chromatography, and reversed phase high-performance liquid chromatography (RP-HPLC), and two antifungal peaks were obtained at the final purification step. After analysis by mass spectrometry (MS) and tandem MS, two purified antifungal agents were deduced to belong to the surfactin family, and designated as surfactin CS30-1 and surfactin CS30-2. Further investigation showed that although the antifungal activity of surfactin CS30-1 is higher than that of surfactin CS30-2, both of them induced the increased generation of reactive oxygen species (ROS) and caused serious damage to the cell wall and cytoplasm, thus leading to the cell death of M. grisea. Our results also show the differences of the antifungal activity and antifungal mechanism of the different surfactin homologs surfactin CS30-1 and surfactin CS30-2, and highlight them as potential promising agents to biocontrol plant diseases caused by M. grisea

Study on Blasting Vibration Control of Brick-Concrete Structure under Subway Tunnel

In order to study the impact of the blasting vibration of subway tunnels on adjacent buildings, taking the tunnel mining method construction of the section between Zhifang Street Station and Metro Town Station of Wuhan Metro Line 27 as the engineering background, the blasting scheme is optimized by reducing the maximum single section charge, multi-section and densifying the surrounding holes. The HHT method and wavelet analysis are used to evaluate the advantages and disadvantages of the optimization scheme from the perspective of energy. The results show that the peak velocity of the blasting vibration is significantly reduced and the frequency is significantly increased after the blasting scheme is optimized. After the blasting scheme is optimized, when the working face is directly below the external wall of the building, the peak vibration velocity is the largest; from the back of the working face to the front of the working face, the peak velocity of the surface particle vibration first increases and then decreases. The frequency band of the optimized blasting vibration signal energy distribution is wider and the energy is more dispersed. This study can provide some practical experience for the design and construction of similar projects