957 research outputs found
Investigation of effects of viscoelastic boundary supports on transient sound radiated from a rectangular plate by modal strain energy method
No full textThis work considers analysis of transient sound radiation from an impact-excited rectangular plate with viscoelastic boundary supports based on the Modal Strain Energy (MSE) method. Vibration of the plate is approximated by double infinite series in the spatial coordinates. Each term of the series is constructed with vibration modes of beams having the same boundary conditions as the considered plate, multiplied by a time dependent function. Modal loss factor of each mode is obtained by the MSE method. The sound pressure for impact excitations is obtained in the time and frequency domain by numerical integration of the Rayleigh integral. Then effects of width of the viscoelastic boundary supports on the vibration response and the radiated sound pressure are investigated. It is shown that there is an optimum width of the support
Effects of <i>Bacillus subtilis</i> ZJ-2019-1 on Zearalenone Toxicosis in Female Gilts
No full textThe purpose of this research was to investigate the toxicity of zearalenone (ZEN) on the growth performance, genital organs, serum hormones, biomarkers, and histopathological changes of female gilts and to evaluate the efficacy of Bacillus subtilis ZJ-2019-1 in alleviating ZEN toxicosis in gilts. Twenty-four female gilts were randomly allocated to four groups with six replicates per group and one gilt per replicate, fed on four feeds prepared previously, which were basic diet (control group, C group), ZEN diet (Z group), Zlb diet (Zlb group) containing B. subtilis ZJ-2019-1 in liquid form, and Zdb diet (Zdb group) containing B. subtilis ZJ-2019-1 in dehydrated form. The results showed that the vulva size and relative weight of reproductive organs had no significant difference in the control group, Zlb group, and Zdb group, but were significantly lower than in the Z group (p p p p p p p p B. subtilis ZJ-2019-1 could naturally remove the ZEN significantly, which ameliorated the reproductive impairment in gilts caused by ZEN. The addition of B. subtilis ZJ-2019-1 to ZEN-contaminated feeds could ameliorate the toxic effects effectively, regardless of liquid or dry culture. Therefore, the B. subtilis ZJ-2019-1 strain has great potential industrial applications
Pharmacokinetics Studies of 12 Alkaloids in Rat Plasma after Oral Administration of Zuojin and Fan-Zuojin Formulas
No full textZuojin formula (ZJ) is a traditional Chinese medicine (TCM) prescription consisted of Coptidis Rhizoma (CR) and Euodiae Fructus (EF), and has been used to treat gastrointestinal (GI) disease for more than 700 years. Fan-Zuojin formula (FZJ) is a related TCM prescription also consisted of CR and EF with the opposite proportion. In recent years, ZJ was getting more attention for its antitumor potential, but the indeterminate pharmacokinetic (PK) behavior restricted its clinical applications, and the PK differences between ZJ and FZJ were also largely unknown. Consequently it is necessary to carry out a full-scale PK study to demonstrate the physiological disposition of ZJ, as well as the comparative PK study between ZJ and FZJ to illustrate the compatibility dose effects. Therefore a liquid chromatographic–tandem mass spectrometry (LC–MS/MS) method was established and validated for the determinations of coptisine, epiberberine, palmatine, berberine, 8-oxocoptisine, 8-oxoepiberberine, noroxyhydrastinine, corydaldine, dehydroevodiamine, evodiamine, wuchuyuamide-I, and evocarpine in rat plasma. PK characteristics of 12 alkaloids after oral administration of ZJ and FZJ were compared, and the result was analyzed and discussed with the help of an in silico study. Then an integrated PK study was carried out with the AUC-based weighting method and the total drug concentration method. The established method has been successfully applied to reveal the PK profiles of the 12 alkaloids in rat plasma after oral administration of ZJ and FZJ. The results showed that: (1) double peaks were observed in the plasma concentration-time (C–T) curves of the alkaloids after ZJ administration; but the C–T curves approximately matched the two-compartment model after FZJ administration; (2) There were wide variations in the absorption levels of these alkaloids; and even for a certain alkaloid, the dose modified systemic exposure levels and elimination rate also varied significantly after administration of ZJ and FZJ extracts. The results could be interpreted as follows: firstly, inhibition effect on GI motility caused by the high content CR alkaloids (especially berberine) in ZJ could delay the Tmax, and increase the absorption and systemic exposure levels of the other alkaloids, and also lead to the double peak phenomenon of these alkaloids. However, for quaternary protoberberine alkaloids (QPA), double peaks were primarily caused by the different Ka value in two intestinal absorption sites. Secondly, absorption was the major obstacle to the systemic exposure level of the alkaloids from CR and EF. In silico and PK studies suggested that the absorption of these alkaloids, except QPAs, mainly depended on their solubility rather than permeability. Thirdly, EF could promote the absorption and accelerate the elimination of QPAs, and had a greater influence on the former than the latter. At last the integrated PK analysis suggested that berberine and dehydroevodiamine could be regarded as the representative components to reflect the PK behaviors of CR and EF alkaloids after administration of ZJ and FZJ. In conclusion, the absorption, elimination and systemic exposure level of these alkaloids were mainly influenced by the proportion of EF and CR, the pharmacological effect on GI motility, and the physicochemical property of these alkaloids. These findings would be helpful for a better understanding of the activities and clinical applications of ZJ, FZJ and other related TCM prescriptions
Hidden periodicities analysis and its application in geophysics
No full textThis paper describes the use of spatial hidden periodicity analysis (SHPA) for the determination of the number of the harmonic components and hidden frequencies. All the estimators are strongly consistent. The method is used for the modeling and forecasting of spatial data of permeability in oil fields of China.Geosciences, MultidisciplinaryMathematics, AppliedStatistics & ProbabilityCPCI-S(ISTP)
Effective components screening and anti-myocardial infarction mechanism study of the Chinese medicine NSLF6 based on "system to system" mode
No full textAbstract Background Shuanglong formula (SLF), a Chinese medicine composed of panax ginseng and salvia miltiorrhiza exhibited significant effect in the treatment of myocardial infarction (MI) in clinical. Because of the complex nature and lack of stringent quality control, it's difficult to explain the action mechanism of SLF. Method In this study, we present a "system to system" (S2S) mode. Based on this mode, SLF was simplified successively through bioactivity-guided screening to achieve an optimized minimal phytochemical composition (new formula NSLF6) while maintaining its curative effect for MI. Results Pharmacological test combining with the study of systems biology show that NSLF6 has activity for treatment MI through synergistic therapeutic efficacies between total ginsenosides and total salvianolic acids via promoting cardiac cell regeneration and myocardial angiogenesis, antagonistic myocardial cell oxidative damage. Conclusions The present S2S mode may be an effective way for the discovery of new composite drugs from traditional medicines.</p
Charm multiplicity and the branching ratios of inclusive charmless b quark decays in the general two-Higgs-doublet models
No full textIn the framework of general two-Higgs-doublet models, we calculate the branching ratios of various inclusive charmless b decays by using the low-energy effective Hamiltonian including next-to-leading order QCD corrections, and examine the current status and the new physics effects on the determination of the charm multiplicity n(c) and semileptonic branching ratio B-SL Within the considered parameter space, the enhancement to the ratio BR(b-->sg) due to the charged-Higgs penguin diagrams can be as large as a factor of 8 (3) in the model III (II), while the ratio BR(b-->no charm) can be increased from the standard model prediction of 2.49 to 4.91 % (2.99%) in model III (II). Consequently, the value of B-SL and n(c) can be decreased simultaneously in model III. The central value of B-SL Will be lowered slightly by about 0.003, but the ratio n(c) can be reduced significantly from the theoretical prediction of n(c) = 1.28 +/- 0.05 in the SM to n(c) = 1.23 +/- 0.05, 1.18 +/- 0.05 for m(H+) = 200, 100 GeV, respectively. We find that the predicted n(c) and the measured n(c) now agree within roughly one standard deviation after taking into account the effects of gluonic charged Higgs penguin diagrams in model III with a relatively light charged Higgs boson.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000165111400046&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Astronomy & AstrophysicsPhysics, Particles & FieldsSCI(E)15REVIEW9null6
The local structure of Lie bialgebroids
No full textWe study the local structure of Lie bialgebroids at regular points. In particular, we classify all transitive Lie bialgebroids. In special cases, they are connected to classical dynamical r-matrices and matched pairs induced by Poisson group actions.Physics, MathematicalSCI(E)8ARTICLE115-286
Partition Energy Absorption of Axially Crushed Aluminum Foam-Filled Hat Sections
No full textThe "interaction effect" between aluminum foam and metal column that takes place when foam-filled hat sections (top-hats and double-hats) are axially crushed was investigated in this paper. Based on experimental examination, numerical simulation and analytical models, a systemic approach was developed to partition the energy absorption quantitatively into the foam filler component and the hat section component, and the relative contribution of each component to the overall interaction effect was therefore evaluated. Careful observation of the collapse profile found that the crushed foam filler could be further divided into two main energy-dissipation regions: densified region and extremely densified region. The volume reduction and volumetric strain of each region were empirically estimated. An analytical model pertinent to the collapse profile was thereafter proposed to find the more precise relationship between the volume reduction and volumetric strain of the foam filler. Combined the superfolding element model for hat sections with the current model according to the coupled method, each component energy absorption was subsequently derived, and the influence of some controlling factors was discussed. According to the finite element analysis and the theoretical modeling, when filled with foam, energy absorption was found to be increased both in the hat section and the foam filler, whereas the latter contributes predominantly to the interaction effect. The formation of the extremely densified region in the foam filler accounts for this effect
Magnetostratigraphy of the Northern Tian Shan foreland, Taxi He section, China
No full textTheTian Shan range formed in the late Cenozoic in response to the northward propagation of deformation related to the India^Eurasia continental collision. Precise timing of theTian Shan uplift is required to understand possible mechanisms of continental lithosphere deformation and interactions between climate, tectonism and erosion.Here, we provide magnetostratigraphic age control on the northern ChineseTian Shan foreland successions. A thorough rock magnetic analysis identifies haematite- and magnetite-bearing alluvial fan deposits in the upper portion of the sampled strata as more reliable palaeomagnetic recorders than magnetite-bearing £uvial and lacustrine deposits that are often maghaemitized in the lower part of the record. As a result, a robust correlation to the geomagnetic polarity time scale is obtained from6 to 2Ma while a tentative correlation is proposed from6 to 16Ma. Sediment accumulation rates increase from155 to 260mMyr-1 at 3.9 ± 0.3Ma.This change coincides with a gradual lithologic transition from £uvial (sandstonedominated) to alluvial fan (conglomerate-dominated) deposits that likely records an approaching erosional source related to tectonically increased subsidence rather than di¡erential compaction. Clear evidence for growth strata starting at an estimated age of ~2Ma provides a minimum age for folding.These results are compared with previous magneotstratigraphic studies from the same and other sections of the northernTian Shan foreland basin fill, thus enabling a critical assessment of the reliability of magnetostratigraphic dating and the significance of sediment accumulation rate variations with respect to facies variations and growth strata. Our results in theTaxiHe section provide a sequence of events that is consistentwith enhanced tectonic forcing starting at ~4Ma, although a climatic contribution must be considered given the close relationship of these ages with the Pliocene climate deterioration
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