Search

Objective Most of the studies on the herb Chuanxiong Rhizoma (CR) have focused on the l - arginine-nitric oxide (NO) pathway, but the nitrate-nitrite-NO (NO3−–NO2−–NO) pathway was rarely investigated. Therefore, the aim of this study was to evaluate the effects and mechanisms of action of CR in coronary artery disease (CAD). Methods The NO3−, NO2− and NO levels were examined in the NO3−–NO2−–NO pathway. High-performance ion chromatography was used to quantify NO3− and NO2− levels. Then, NO was quantified using a multifunctional enzyme marker with a fluorescent probe. The tension of aortic rings was measured using a multi myograph system. Results High content of NO3− and low content of NO2− was found in CR, and which could potently convert NO3− to NO2− in the presence of endogenous reductase enzyme. Incubating human coronary artery endothelial cells (HCAECs) with CR-containing serum showed that CR significantly decreased the NO3− content and increased the levels of NO2− and NO in the cells under hypoxic conditions. In addition, CR significantly relaxed isolated aortic rings when the l - arginine –NO pathway was blocked. The optimal concentration of CR for relaxation was 200 mg/mL. Conclusion CR supplements large amounts of NO in cells and vessels to achieve relaxation via the NO3−–NO2−–NO pathway, thereby making up for the deficiency caused by the lack of NO after the l - arginine-NO pathway is suppressed. This study also supports the potential use of a traditional Chinese herb for future drug development.

CRISPR-Cas provides bacteria and archaea with immunity against invading phages and foreign plasmid DNA and has been successfully adapted for gene editing in a variety of species. The class 2 type VI CRISPR-Cas effector Cas13a targets and cleaves RNA, providing protection against RNA phages. Here we report the repurposing of CRISPR-Cas13a to inhibit human immunodeficiency virus type 1 (HIV-1) infection through targeting HIV-1 RNA and diminishing viral gene expression. We observed strong inhibition of HIV-1 infection by CRISPR-Cas13a in human cells. We showed that CRISPR-Cas13a not only diminishes the level of newly synthesized viral RNA, either from the transfected plasmid DNA or from the viral DNA, which is integrated into cellular DNA, but it also targets and destroys the viral RNA that enters cells within viral capsid, leading to strong inhibition of HIV-1 infection. Together, our results suggest that CRISPR-Cas13a provides a potential novel tool to treat viral diseases in humans., Graphical Abstract, The class 2 type VI CRISPR-Cas effector Cas13a targets and cleaves RNA, providing protection against RNA phages. Yin et al. demonstrate that CRISPR-Cas13a targets and cleaves the HIV RNA genome and mRNA, leading to strong inhibition of HIV-1 infection.

Interferon-regulated myxovirus resistance protein B (MxB) is an interferon-induced GTPase belonging to the dynamin superfamily. It inhibits infection with a wide range of different viruses, including HIV-1, by impairing viral DNA entry into the nucleus. Unlike the related antiviral GTPase MxA, MxB possesses an N-terminal region that contains a nuclear localization signal and is crucial for inhibiting HIV-1. Because MxB previously has been shown to reside in both the nuclear envelope and the cytoplasm, here we used bioinformatics and biochemical approaches to identify a nuclear export signal (NES) responsible for MxB's cytoplasmic location. Using the online computational tool LocNES (Locating Nuclear Export Signals or NESs), we identified five putative NES candidates in MxB and investigated whether their deletion caused nuclear localization of MxB. Our results revealed that none of the five deletion variants relocates to the nucleus, suggesting that these five predicted NES sequences do not confer NES activity. Interestingly, deletion of one sequence, encompassing amino acids 505-527, abrogated the anti-HIV-1 activity of MxB. Further mutation experiments disclosed that amino acids 515-519, and Pro-515 in particular, regulate MxB oligomerization and its binding to HIV-1 capsid, thereby playing an important role in MxB-mediated restriction of HIV-1 infection. In summary, our results indicate that none of the five predicted NES sequences in MxB appears to be required for its nuclear export. Our findings also reveal several residues in MxB, including Pro-515, critical for its oligomerization and anti-HIV-1 function.

The main purpose of this study was to examine the longitudinal mediation effects of multiple gaming motives from online game involvement to problematic Internet use (PIU). In terms of mediators, the present study included three specific gaming motivations - escapism, advancement, and socializing. A sample of 389 gamers participated in the study from freshman to junior college years. Gaming involvement was collected at the freshman year, motives at sophomore, and PIU at junior. Initially, the three gaming motives were examined separately for their longitudinal mediation effects in a series of single-mediator models. Next, the three motives were simultaneously included in a multiple-mediator model to compare the relative levels of their mediation effects from gaming involvement to PIU across a period of two years. In the multiple-mediator model, the most compelling results showed that escapism and advancement were positively associated with PIU, yet socializing was not; socializing failed to significantly predict later PIU. Also, the direct effect of gaming involvement on PIU was weak and failed to reach significant level, contradicting to the findings of previous cross-sectional studies. Many game players experience great pleasure from immersing themselves in a virtual world, and often to the extent of developing addictive symptoms. This phenomenon is referred to as “pull” effect which is considered comparable to the motive of “pursuing in-game advancement” in the present study. Conversely, frustrations or other negative experiences in real life might also bring about a “push” effect that tugs players into gaming. The motive of escapism from the real-life in this study resembles the so-called “push” effect. The authors suggest when gamers demonstrated social motive during game time, such as participating in a gamer community and collaborating with the others despite being socially withdrawn in real life, it would be less reasonably to be regarded as PIU. During game time, if gamers experience a temporary sense of well-being, it might help to vent their real-life frustration. However, an excessive use of this emotion-focused coping strategy might still increase the risk of PIU.

Objectives In recent years, Klebsiella pneumoniae has emerged as a leading cause of nosocomial infection owing to the rising prevalence of multidrug-resistant strains, particularly carbapenem-resistant isolates. In this study, the complete genome sequence of carbapenem-resistant K. pneumoniae SWU01 was determined. Methods Antimicrobial susceptibilities and hypermucoviscous phenotype were determined by the disk diffusion method and positive string test, respectively. Multilocus sequence typing (MLST) was performed using the K. pneumoniae MLST database, and capsular serotype was analysed using the BIGSdb-Kp database with the nucleotide sequence of the variable region (CD1-VR2-CD2) of wzc . The complete genome sequence was obtained via the PacBio RS II platform, and antimicrobial resistance genes were identified using ResFinder 2.1. Results SWU01 was resistant to all antibiotics tested except polymyxin B and minocycline. This strain showed a hypermucoviscous phenotype with serotype K47 belonging to the ST11 clone. The complete genome consists of a 5 536 506-bp circular chromosome and a 162 552-bp plasmid, with a G+C content of 57.4%. A total of 5537 protein-coding sequences, 85 tRNAs, 25 rRNAs, 12 non-coding RNA genes and 157 pseudogenes were identified in the genome. Thirteen acquired antibiotic resistance genes were detected (eight in the chromosome and five in the plasmid). Conclusions Here we present the first whole-genome sequence of a carbapenem-resistant hypermucoviscous K. pneumoniae isolate SWU01 with capsular serotype K47 belonging to ST11 from a patient in China, which may serve as a reference sequence for further understanding of the pathogenesis and multidrug resistance mechanisms of this species.

Endothelin-converting enzyme-1 (Ece-1), a crucial component of the Endothelin signaling pathway, is required for embryonic development and is an important regulator of vascular tone, yet the transcriptional regulation of the ECE1 gene has remained largely unknown. Here, we define the activity and regulation of an enhancer from the human ECE1 locus in vivo. The enhancer identified here becomes active in endothelial progenitor cells shortly after their initial specification and is dependent on a conserved FOX:ETS motif, a composite binding site for Forkhead transcription factors and the Ets transcription factor Etv2, for activity in vivo. The ECE1 FOX:ETS motif is bound and cooperatively activated by FoxC2 and Etv2, but unlike other described FOX:ETS-dependent enhancers, ECE1 enhancer activity becomes restricted to arterial endothelium and endocardium by embryonic day 9.5 in transgenic mouse embryos. The ECE1 endothelial enhancer also contains an evolutionarily-conserved, consensus SOX binding site, which is required for activity in transgenic mouse embryos. Importantly, the ECE1 SOX site is bound and activated by Sox17, a transcription factor involved in endothelial cell differentiation and an important regulator of arterial identity. Moreover, the ECE1 enhancer is cooperatively activated by the combinatorial action of FoxC2, Etv2, and Sox17. Although Sox17 is required for arterial identity, few direct transcriptional targets have been identified in endothelial cells. Thus, this work has important implications for our understanding of endothelial specification and arterial subspecification.

We studied the content of the team mental model with a case study about a successful online game team. This team was formed by high-ranking managers in a large raid guild to conduct a raid in War of Worldcraft. They were interviewed with a set of 5-W questions developed according to the conceptualizations of team mental model (Levine & Moreland, 1991). Toward the interview protocol, a content analysis was conducted with two-cycle coding method from exploratory to explanatory and a hierarchical framework from code, category, theme, to theory were generated to describe the team mental model. In the first cycle, 17 codes were extracted from participants' own wording for concepts that were shared by whom controlled various gaming characters. These codes are knowledge convergence about the problem at-hand, actors, events, affects and outcomes - what the core gamers have experienced through the collaborative gaming process. In the second cycle, coding was guided by learning theories. Six categories, mingled from 17 codes, showed collective knowledge of co-work process, leaders' works, work under supervision, seeking joint fun, relationship oriented, and balance between extrinsic-intrinsic motivations. From 6 categories, two themes were synthesized: the team (1) performed ''joint hard work'' for (2) seeking ''joint hard fun.'' The first theme comprised declarative and procedural knowledge representations and we consider it to be the commonality between this game team and ordinary work/learning teams. The second theme was composed of affective and cognitive evaluation components about intrinsic motivation which is in accordance with Self-determination theory (SDT, Deci & Ryan, 2000). In general, ''Jointly hard work for hard fun'' is the gist content of the team mental model. We found ample evidences that members explicitly recall shared motivational beliefs of team mates and emotional-motivational events in gaming. Based on the results of this study, several implications have been addressed for teachers to enhance students' intrinsic motivation in conducting quality Computer-Supported Collaborative Learning. Future studies are needed to further explore the relationship between the quality of team mental models and team-level performance.

Cross-lagged analysis of panel survey data collected from Taiwanese college students (initially 387 males and 370 females) was used to examine the temporal relationship between problematic Internet use (PIU) and lifestyle changes during the first year in college. We hypothesized that a reciprocal relationship might exist between PIU and lifestyle changes. Structural equation modeling was adopted to test several nested cross-lagged relationship models. The results showed that four measures of lifestyle changes and PIU were moderately to highly stable across one year. Moreover, PIU in freshman year predicted negative changes in lifestyle in the following year, including a reduction of physical and social activities, irregular diet and unhealthy sleep. Lifestyle changes in freshman year, in contrast, did not predict PIU in sophomore year; the hypothesized reciprocal relationship between PIU and lifestyle changes was not warranted. Implications and limitations are discussed.

This study uses an integrated model utilizing a small-world network and choice-based conjoint adoption model to examine the dynamics of consumer choice and diffusion in the hybrid electric vehicles market. It specifically compares the effectiveness of hybrid diffusion through the traditional word of mouth and via social media. The results show that without the advantage of increased gasoline prices, the growth of the hybrid vehicles market is insignificant, and that the Internet has a significant influence on the word of mouth effect in the purchasing process. Hybrid electric vehicles market shares decrease dramatically as a result of negative word of mouth communication via social media. The use of a higher fuel taxes is more effective than providing a subsidy for disposing of old vehicles and purchasing a hybrid.

PtSn anode catalyst supported on carbon fiber was taken as the anode catalyst of the MEA. Commercial Pt/C as the cathode catalyst was used in MEA as the cathode catalyst. The Nafion 115 membrane was the proton exchange membrane of the MEA. MEA was fabricated by hot-pressing. The sing flat cell was assembled with the prepared MEA. The influences of temperature, ethanol concentration, rates of liquor and O 2 were studied. The results showed that the performance of the fuel was better when the concentration of ethanol was 1.0 mol/L, the rate of liquor was 1.0 mL/min, the temperature was 80°C, and the rate of O 2 was 100 mL/min, the maximum power density of the fuel reached about 18.2 mW/cm 2 .

In this paper, we have developed and revealed the wafer-level LED system-in-packaging (WL-LED-SiP) design and process platform. This platform provided an LED system solution with high packaging density, high performance, high reliability and cost effectiveness. Camera phone flash module was adopted as a test vehicle for demonstrating LED-SiP platform technologies, including wafer-level (WL) process integration with micro electromechanical system (MEMS) reflector, cavity-based lithography and through silicon via (TSV) filling. Meanwhile, LED flash module performance, including correlated color temperature (CCT), color rendering index (CRI), light energy and distribution, was characterized. The delivered LED-SiP flash module showed wide-view angle design of 80° × 50° and light energy of 5.7 lx s @ 1/30 s. The volume of the module is 8 × 11 × 4 mm3.

Tuberculosis is a human disease caused by infection with Mycobacterium tuberculosis. M. tuberculosis (Mtb) is a facultative intracellular pathogen. The alveolar macrophages provide a critical niche for the intracellular pathogen. It has been shown that virulent strains mycobacteria (Mtb-H37Rv, Mycobacterium bovis) induce less apoptosis in host macrophage than avirulent mycobacteria strains (Bacillus Calmette-Guérin, H37Ra). Comparative genomics analysis has revealed that the region of difference (RD1) of M. tuberculosis is absent from all strains of Bacillus Calmette-Guérin (BCG). On the contrary, it presents in all virulent strains of M. tuberculosis and M. bovis. The culture filtrate protein 10 (CFP10) and early secretory antigenic target protein 6 (ESAT6) are encoded by RD1 genes Rv3874 and Rv3875, respectively. Recent studies indicated that the CFP10 and ESAT6 played an important role in M. tuberculosis virulence. It has been shown that incorporation of the RD1 region into BCG to restore the expression of CFP10 and ESAT6 leads to increasing the virulence and immunogenicity of bacterium. On the contrary, deletion of the genes encoding CFP10 and ESAT6 from the virulent M. bovis strain results in attenuation of virulence. Meanwhile, several studies showed that CFP10 and ESAT6 could inhibit and/or promote the production of tumor necrosis factor α (TNF-α) from macrophages. Furthermore, TNF-α can induce apoptosis and necrosis of infected macrophages in tuberculosis. Considering above results, we hypothesize that the CFP10 and ESAT6 may be involved in the virulence of Mycobacterium through modulating macrophage cell death.

The developing heart contains an inner tube of specialized endothelium known as endocardium, which performs multiple essential functions. In spite of the essential role of the endocardium in heart development and function, the transcriptional pathways that regulate its development remain largely undefined. GATA4 is a zinc finger transcription factor that is expressed in multiple cardiovascular lineages and is required for endocardial cushion development and embryonic viability, but the transcriptional pathways upstream of Gata4 in the endocardium and its derivatives in the endocardial cushions are unknown. Here, we describe a distal enhancer from the mouse Gata4 gene that is briefly active in multiple cardiac lineages early in cardiac development but restricts to the endocardium where it remains active through cardiogenesis. The activity of this Gata4 cardiac enhancer in transgenic embryos and in cultured aortic endothelial cells is dependent on four ETS sites. To identify which ETS transcription factors might be involved in Gata4 regulation via the ETS sites in the enhancer, we determined the expression profile of 24 distinct ETS factors in embryonic mouse hearts. Among multiple ETS transcripts present, ETS1, FLI1, ETV1, ETV5, ERG, and ETV6 were the most abundant in the early embryonic heart. We found that ETS1, FLI1, and ERG were strongly expressed in the heart at embryonic day 8.5 and that ETS1 and ERG bound to the endogenous Gata4 enhancer in cultured endothelial cells. Thus, these studies define the ETS expression profile in the early embryonic heart and identify an ETS-dependent enhancer from the Gata4 locus.

The novel Influenza A (H1N1) virus is attacking the world in 2009. Among others, campuses in China, particularly most university/college campuses for bachelor students, are at-risk areas where many susceptible youngsters live. They most likely interact with each other quite often in dormitories, classrooms and refectories. We model the pandemic influenza A (H1N1) transmission through campus contacts and then forecast the effectiveness of interventions, based on a previously presented Complex Agent Network model for simulating infectious diseases [1]. Our results suggest that pandemic influenza A (H1N1) on campus will die out even with no intervention taken; the most effective intervention is still quarantining confirmed cases as early as possible and, in addition, vaccinating susceptible people can further decrease the maximum daily number of the infected. This study can support quantitative experimentation and prediction of infectious diseases within predefined areas, and assessment of intervention strategies. (C) 2010 Published by Elsevier Ltd.

International audience; We report an unexpected role for protease signaling in neural tube closure and the formation of the central nervous system. Mouse embryos lacking protease-activated receptors 1 and 2 showed defective hind-brain and posterior neuropore closure and developed exencephaly and spina bifida, important human congenital anomalies. Par1 and Par2 were expressed in surface ectoderm, and Par2 was expressed selectively along the line of closure. Ablation of G i/z and Rac1 function in these Par2-expressing cells disrupted neural tube closure, further implicating G protein-coupled receptors and identifying a likely effector pathway. Cluster analysis of protease and Par2 expression patterns revealed a group of membrane-tethered proteases often coexpressed with Par2. Among these, matriptase activated Par2 with picomolar potency, and hepsin and prostasin activated matriptase. Together, our results suggest a role for protease-activated receptor signaling in neural tube closure and identify a local protease network that may trigger Par2 signaling and monitor and regulate epithelial integrity in this context.

The cells of the second heart field (SHF) contribute to the outflow tract and right ventricle, as well as to parts of the left ventricle and atria. Isl1, a member of the LIM-homeodomain transcription factor family, is expressed early in this cardiac progenitor population and functions near the top of a transcriptional pathway essential for heart development. Isl1 is required for the survival and migration of SHF-derived cells into the early developing heart at the inflow and outflow poles. Despite this important role for Isl1 in early heart formation, the transcriptional regulation of Isl1 has remained largely undefined. Therefore, to identify transcription factors that regulate Isl1 expression in vivo, we screened the conserved noncoding sequences from the mouse Isl1 locus for enhancer activity in transgenic mouse embryos. Here, we report the identification of an enhancer from the mouse Isl1 gene that is sufficient to direct expression to the SHF and its derivatives. The Isl1 SHF enhancer contains three consensus Forkhead transcription factor binding sites that are efficiently and specifically bound by Forkhead transcription factors. Importantly, the activity of the enhancer is dependent on these three Forkhead binding sites in transgenic mouse embryos. Thus, these studies demonstrate that Isl1 is a direct transcriptional target of Forkhead transcription factors in the SHF and establish a transcriptional pathway upstream of Isl1 in the SHF.

The vascular system is essential for embryonic development and adult life. Aberrant vascularization is associated with numerous diseases, including cancer, atherosclerosis, retinopathy, and stroke. Vascular development begins when mesodermal cells differentiate into endothelial cells, which then form primitive vessels. It has been hypothesized that endothelial-specific gene expression may be regulated combinatorially, but the transcriptional mechanisms governing vascular gene expression remain incompletely understood. Here, we identify a transcriptional code, consisting of Forkhead and Ets factors, which is required and sufficient for vascular development and endothelial gene expression through combinatorial activation of a composite cis-acting element. We show that the presence of this FOX:ETS motif is an effective predictor of endothelial-specific enhancers. These studies establish a paradigm in which two broadly expressed classes of transcription factors regulate tissue specific expression combinatorially through a single composite cis-acting element. This mechanism has broad implications for understanding differentiation and gene expression in many tissues.

Nitrogen and ferrum co-doped titania photocatalyst was prepared by the sol–gel route. The prepared photocatalyst was characterized by various techniques including X-ray diffraction (XRD), UV–vis diffusive reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), and N2 adsorption–desorption isotherm. The photocatalytic activity of the co-doped titania photocatalyst was evaluated by the degradation of methyl orange (MO) from aqueous solution under visible light irradiation and was compared with that of the commercial TiO2 photocatalyst (Degussa P25). The results revealed that the nitrogen doping could lead to the response to visible light and that the ferrum doping could improve the photocatalytic performance. The effects of the component and the annealing temperature of the co-doped titania photocatalyst on the photocatalytic activity were investigated.

Dry core rot of apple (DCR) and Alternaria black rot of citrus (ABR) have in the past respectively been ascribed to Alternaria alternata and A. citri. In recent years, however, it has been speculated that several other species of Alternaria could also be associated with these diseases. In an attempt to elucidate the identity of these taxa, 25 isolates associated with DCR, and 26 isolates associated with ABR were selected for molecular characterisation. Nucleotide sequences of 1116 sites including the histone gene section and the internal transcribed spacers (ITS 1 and 2) of the rRNA gene were determined for these isolates. The gene trees generated from the individual and combined data sets using maximum parsimony, maximum likelihood and neighbour-joining analysis methods distinguished five clades with strong bootstrap support, namely Alternaria sp., A. arborescens, A. infectoria, A. tenuissima, and a clade containing isolates variable in morphology, referred to as the Alternaria group. In the alignment of the combined ITS and histone data set, unique transition/transversion substitutions, as well as positional insertions and deletions were observed for each of the above clades. In addition, key sequences in the form of serial composing nucleotides in both the ITS and histone sections of the alignment were also discovered for the molecular identification of A. arborescens, A. infectoria and A. tenuissima. The final phylogeny also indicated that no host specificity existed among the species associated with these two post-harvest disease complexes. Contrary to the host specificity observed on leaf diseases of these hosts in the field, it appears that the post-harvest diseases are the result of adverse storage conditions and opportunism of different small-spored Alternaria spp.