1,370 research outputs found
Investigation of the Antiasthmatic Properties of Ethanol Extract of Callophyllis japonica in Mice
Purpose: To determine whether an ethanol extract from Callophyllis japonica (C. japonica) could attenuate indices of airway inflammation in a murine model of ovalbumin (OVA)-induced asthma.Methods: The free radical scavenging activity of the C. japonica ethanol extracts (CJE) were investigated using an electron spin resonance (ESR) system. To make develop animal model of asthma, mice were sensitized and challenged with OVA.Results: CJE exhibited considerable scavenging activity of 71.08 Âą 0.73, 79.11 Âą 6.04%, 75.95 Âą 7.01%, and 48.56 Âą 5.96% of DPPH, alkyl, superoxide, and hydroxyl radicals, respectively. The successive intraperitoneal administration of CJE reduced the number of eosinophils in bronchoalveolar lavage (BAL) fluid, development of airway hyperresponsiveness (AHR), an increase in pulmonary Th2 cytokines, and allergen-specific immunoglobulin E (IgE).Conclusion: Administration of CJE markedly alleviates all indices of airway inflammation. This study provides evidence that CJE plays a critical role in the amelioration of the pathogenetic process of allergic asthma in mice.Keywords: Asthma, Phenolic contents, Free radical scavenging, Airway hyper-responsiveness, Cytokines, Immunoglobulin
A transient homotypic interaction model for the influenza A virus NS1 protein effector domain
Influenza A virus NS1 protein is a multifunctional virulence factor consisting of an RNA binding domain (RBD), a short linker, an effector domain (ED), and a C-terminal 'tail'. Although poorly understood, NS1 multimerization may autoregulate its actions. While RBD dimerization seems functionally conserved, two possible apo ED dimers have been proposed (helix-helix and strand-strand). Here, we analyze all available RBD, ED, and full-length NS1 structures, including four novel crystal structures obtained using EDs from divergent human and avian viruses, as well as two forms of a monomeric ED mutant. The data reveal the helix-helix interface as the only strictly conserved ED homodimeric contact. Furthermore, a mutant NS1 unable to form the helix-helix dimer is compromised in its ability to bind dsRNA efficiently, implying that ED multimerization influences RBD activity. Our bioinformatical work also suggests that the helix-helix interface is variable and transient, thereby allowing two ED monomers to twist relative to one another and possibly separate. In this regard, we found a mAb that recognizes NS1 via a residue completely buried within the ED helix-helix interface, and which may help highlight potential different conformational populations of NS1 (putatively termed 'helix-closed' and 'helix-open') in virus-infected cells. 'Helix-closed' conformations appear to enhance dsRNA binding, and 'helix-open' conformations allow otherwise inaccessible interactions with host factors. Our data support a new model of NS1 regulation in which the RBD remains dimeric throughout infection, while the ED switches between several quaternary states in order to expand its functional space. Such a concept may be applicable to other small multifunctional proteins
A Multidimensional, Comparative Analysis of the Regional Entrepreneurship Performance in the Central and Eastern European EU Member Countries
Entrepreneurship research has changed considerably over the last 30 years, and
today entrepreneurship is widely accepted as a major driving force of economic
development, of the creation of employment and of innovation (Acs et al. 2008,
2009; Carree and Thurik 2003; Braunerhjelm et al. 2010; Lazear 2004). However,
the dynamics of the effect of entrepreneurship are very diverse and depend on many
factors such as the development level of the home country and the institutional
context (Acs et al. 2008). Whilst previous studies on entrepreneurship have focused
on examining the role of entrepreneurial activity and start-up rates, recent research has shown that not all entrepreneurial activity is effective. High growth rates, such
as those achieved by innovative gazelle companies, are responsible for the bulk of
new job creation and growth, whilst other non-innovative or traditional businesses
have only minor economic influence (Acs and Mueller 2008; Baumol 1996; Wong
et al. 2005)
Observation of a ppb mass threshoud enhancement in \psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p}) decay
The decay channel
is studied using a sample of events collected
by the BESIII experiment at BEPCII. A strong enhancement at threshold is
observed in the invariant mass spectrum. The enhancement can be fit
with an -wave Breit-Wigner resonance function with a resulting peak mass of
and a
narrow width that is at the 90% confidence level.
These results are consistent with published BESII results. These mass and width
values do not match with those of any known meson resonance.Comment: 5 pages, 3 figures, submitted to Chinese Physics
Chemical Composition and Antioxidant Activities of Broussonetia papyrifera Fruits
Fruits of Broussonetia papyrifera from South China were analyzed for their total chemical composition, and antioxidant activities in ethanol and aqueous extracts. In the fruit of this plant, the crude protein, crude fat and carbohydrates was 7.08%, 3.72% and 64.73% of dry weight, respectively. The crude protein, crude fat and carbohydrates were 15.71%, 20.51% and 36.09% of dry weight, respectively. Fatty acid and amino acid composition of the fruit were analyzed. Unsaturated fatty acid concentration was 70.6% of the total fatty acids. The percentage of the essential amino acids (EAAs) was 40.60% of the total amino acids. Furthermore, B. papyrifera fruit are rich in many mineral elements and vitamins. Total phenolic content was assessed using the Folin-Ciocalteau assay, whereas antioxidant activities were assessed by measuring the ability of the two extracts to scavenge DPPH radicals, inhibit peroxidation, and chelate ferric ions. Their reducing power was also assessed. Results indicated that the aqueous extract of B. papyrifera was a more potent reducing agent and radical-scavenger than the ethanol extract. GCâMS analysis of the ethanol extract showed the presence of some acid-containing compounds. The changes in total phenolic content and antioxidant capacity in B. papyrifera from four different regions grown under normal conditions were assessed. The antioxidant activity of different extracts was positively associated with their total phenolic content. These results suggest that the fruit of B. papyrifera could be used in dietary supplement preparations, or as a food additive, for nutritional gain, or to prevent oxidation in food products
Synthesis of Novel Flower-Like Zn(OH)F via a Microwave-Assisted Ionic Liquid Route and Transformation into Nanoporous ZnO by Heat Treatment
Zinc hydroxide fluoride (Zn(OH)F) with novel flower-like morphology has been prepared via a microwave-assisted ionic liquid route. The flower-like Zn(OH)F particle has six petals and every petal is composed of lots of acicular nano-structure. Nanoporous ZnO is obtained by thermal decomposition of as-prepared Zn(OH)F in air, and the flower-like morphology is well retained. In the process of synthesis, ionic liquid 1-Butyl-3-methylimidazolium tetrafluoroborate is used as both the reactant and the template
Recombinant AAV-mediated HSVtk gene transfer with direct intratumoral injections and Tet-On regulation for implanted human breast cancer
BACKGROUND: HSVtk/ganciclovir (GCV) gene therapy has been extensively studied in tumors and relies largely on the gene expression of HSVtk. Most studies, however, have failed to demonstrate any significant benefit of a controlled gene expression strategy in cancer treatment. The Tet-On system is commonly used to regulate gene expression following Dox induction. We have evaluated the antitumor effect of HSVtk/ganciclovir gene therapy under Tet-On regulation by means of adeno-associated virus-2 (AAV-2)-mediated HSVtk gene transfer with direct intratumoral injections in mice bearing breast cancer tumors. METHODS: Recombinant adeno-associated virus-2 (rAAV) was constructed and transduced into MCF-7 cell line. GCV treatment to the rAAV infected MCF-7 cells was performed by MTT assay under the doxycycline (Dox) induction or without Dox induction at a vp (viral particle) number of âĽ10(4 )/cell. The virus was administered intratumorally to nude mice that had also received GCV intraperitoneally. The antitumor effects were evaluated by measuring tumor regression and histological analysis. RESULTS: We have demonstrated that GCV treatment to the infected MCF-7 cells under the Dox induction was of more inhibited effects than those without Dox induction at âĽ10(4 )vp/cell. In ex vivo experiments, tumor growth of BALB/C nude mice breast cancer was retarded after rAAV-2/HSVtk/Tet-On was injected into the tumors under the Dox induction. Infiltrating cells were also observed in tumors after Dox induction followed by GCV treatment and cells were profoundly damaged. The expression of HSVtk gene in MCF-7 cells and BALB/C nude mice tumors was up-regulated by Tet-On under Dox induction with reverse transcription-PCR (RT-PCR) analysis. CONCLUSION: The antitumor effect of rAAV-mediated HSVtk/GCV gene therapy under the Dox induction with direct intratumoral injections may be a useful treatment for breast cancer and other solid tumors
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
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