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The aim of this work was to construct a new type of system for the green extraction and efficient separation of Ginkgo biloba leaf polyprenols (GBP). First, cell disruption technologies (enzymolysis, ultrasound, microwave and ball milling) coupled with deep eutectic solvents (DES) were used to extract polyprenyl acetates (PA) from Ginkgo biloba leaves. Results showed that ball milling was the best assisted extraction method, and the amount of PA was 89.88 mg/g. Then, a novel silver-loaded material with selectivity for PA was synthesized, characterized and utilized to absorb PA from the DES extraction solution. The purity of the PA quickly reached 71.28 % after being separated by the silver-loaded material. Finally, saponification and molecular distillation were adopted to remove non-GBP ingredients, and a high-purity GBP (99.80 %) was obtained by optimizing its processing conditions. This study provides a technical support for the development of a green and efficient GBP separation method and lays the foundation for the fabrication of GBP-based drugs, health products and cosmetics.

Lacquer wax represents a significant resource derived from the berries of Toxicodendron vernicifluum in China. The main chemical component of lacquer wax is fatty acid. The fatty acid isopropyl ester prepared from this acid has played a role in enhancing skin penetration and spreading properties, which makes it suitable for use as an important material in washing, cosmetics, and pharmaceuticals. In this study, the isopropyl ester of lacquer wax was synthesized by lipase-catalyzed transesterification for the first time ever. In addition, microemulsion of lacquer wax-based isopropyl ester (LW-IPE) was prepared by adding surfactant, co-surfactant, and water to solve the flocculation phenomenon of LW-IPE. The microemulsion was characterized by its stability, conductivity, viscosity, and particle size, which confirmed the formula of water-in-oil (W/O) microemulsion. The W/O microemulsion demonstrated an excellent thermodynamic stability in the temperature range between 20 °C and 40 °C and was stabilized with the addition of NaCl. In vitro evaluation of protection against ultraviolet light (UVA and UVB) demonstrated that arbutin in W/O microemulsion is capable to protect against UVA. This study is believed as providing valuable information on the performance of microemulsion systems suitable for use in the cosmetics and pharmaceuticals industries.

Polyprenols extracted from Ginkgo biloba leaves is a kinds of unsaturated compound containing double bonds. Traditionally, the separation methods for the polyprenols are lack of selectivity and their separation efficiency are low. We synthesized two kinds of functional nano-silica containing silver ions materials (AgTCM and AgTCN) which have selectivity for unsaturated compounds to separate Ginkgo biloba leaves polyprenols for the first time. AgTCN displays exceptionally high selectivity for polyprenols and high stability under extended heat and light exposure, while silver is virtually immobile during solvent elution. Importantly, the exceptional stability of AgTCN gives rise to much higher polyprenols recovery than conventional silica gel during the chromatographic elution. In addition, we found that the adsorption of polyprenols onto the AgTCN conforms to pseudo-second-order kinetic model and AgTCN has strong affinity with polyprenols by analyzing Langmuir, Freundlich, Temkin-Pyzhev, and Dubinin-Radushkevich isotherms. The calculation results of thermodynamic parameters demonstrate that decrease of temperature in favor of increasing the adsorbing capacity of polyprenols onto the AgTCN, and the adsorption process of which is exothermic reaction. Our results pave the way for the novel separation methods of polyprenols from Ginkgo biloba leaves.

Olive leaf extract pretreated by enzymolysis was selected for studying the thermal stability at different heating rates by thermogravimetric coupled with infrared spectroscopy (TG–FTIR) and nonisothermal theoretical analysis, and products analysis by pyrolysis–gas chromatography–mass spectrometry (Py–GC–MS). Results revealed that thermal decomposition of ethyl acetate extract from olive leaf extract pretreated by enzymolysis (EAEEH) consisted of two steps and had a lower thermal stability. The nonisothermal decomposition kinetics mechanism of EAEEH was D3 model (three-dimensional diffusion, Jander equation, the first step) and F3 model (chemical reaction, n = 3, the second step). TG–IR showed –CH3, –C=C–, –OH, –C–O were continuously accelerated to produce, and evolved gas were CO2, water, CO and CH4 at the end. In addition, it was found that there were mainly polyphenols with phenolic hydroxyl groups in the pyrolysis products by Py–GC–MS, and it was also explained for the thermal stability results. This will provide a theoretical guidance for thermal application of EAEEH in the safe natural food additives, cosmetic and medicine.

The nonisothermal decomposition kinetics of Ginkgo biloba leaves polyprenol (GBP) and cleaved situation of its chemical bond during thermal decomposition process were first investigated using thermogravimetric (TG) and TG-FTIR technology. The results of thermal decomposition kinetics revealed that the nonisothermal decomposition mechanism of GBP corresponds to first-order chemical reaction with n = 1, integral form g(a) = –ln(1 – a) and differential form f(a) = 1 – a. TG-FTIR results demonstrated that absorbance of –CH3, unsaturated C–H bond, =CH2, accumulated C=C, –OH, and so on constantly increased with thermal decomposition reaction went on. In addition, storage life of GBP was also evaluated. These data could provide theoretical guidance for purification under high temperature and other thermal application of GBP.

The vibration prediction model of the key vibration source points of a vehicle platform is studied. Starting from the analysis of the factors affecting the vibration response and the correlation analysis, the key factors affecting the vibration response of the same vehicle structure are sorted out. The vibration prediction model of the key vibration source points is established by using neural network, and using the measured data to verify the accuracy of the vibration prediction model of the cabin section I, cabin II and cabin III of the platform. The results show that in the frequency range of 1∼500Hz, the maximum error of root mean square of cabin I is 2.75dB, that of cabin II is 2.3dB, and that of cabin II is 2.97dB.

Polyprenol is an important active ingredient in Ginkgo biloba leaves (GBL) with great industrial application potential. In this paper, a novel high energy ball milling extraction technology coupled with silver-thiolate material purification method was developed, with which a high purity of GBL polyprenol (GBP) was obtained. Results showed that this method had a high extraction efficiency, and GBP of a purity up to 99.8 % was produced. GBP liposomal gel (GLG) was prepared, and its stability, rheological property, release behavior and antibacterial activity were evaluated. According to the results, GLG had a small particle size and high homogeneity which was desirable for topical application, and it also manifested good physiochemical stability and suitable plastic flow property. In addition, GLG illustrated excellent inhibitory effect against Staphylococcus aureus, Escherichia coli, Candida albicans and Streptococcus pneumoniae, and the minimal inhibitory concentration was 25∼200 μg/mL. The systematic research provided a useful method for the biorefining of GBL.

A gallic acid catalyzed hydration strategy from alkynes under mild conditions has been developed. The catalyst system exhibits excellent activity, thus avoiding the use of any transition metal, strong acids or other toxic reagent as cocatalysts. Recycling experiments were conducted, and this procedure can be scaled up. Other tannins such as tannic acid can also be applied in this reaction which shows the potential utilization of natural feedstocks.

The aim of this study was to separate antityrosinase compounds of the ethyl acetate fraction from Rhus verniciflua Stokes using medium pressure liquid chromatography. Among the different fractions, the Fr.6 fraction showed the highest antityrosinase capacity (96.5%), followed by the Fr.5 fraction (85.6%). The Fr.1 fraction showed the lowest antityrosinase capacity (12.4%). Bioactivity-guided fractionation of Fr.5.5 and Fr.6.4 led to the isolation and identification of butin and sulfuretin. Then the inhibitory effects of butin and sulfuretin on the monophenolase and diphenolase activity of mushroom tyrosinase were investigated. The results showed that butin and sulfuretin can act as potent inhibitors of monophenolase and diphenolase activities of the enzyme, and the IC50 of the butin and sulfuretin were 16.0 μmol/L and 13.64 μmol/L, respectively. The lag period of the enzyme was obviously lengthened; it was estimated to be 1 min in the absence of inhibitor, extended to 26 min in the presence of 185 μmol/L of butin, and 6 min in the presence of 111.1 μmol/L of sulfuretin. A kinetic analysis showed that butin and sulfuretin are competitive inhibitors. The results revealed that the butin and sulfuretin took up the loci of the substrate combined with enzyme, or blocked the anionic initiation by eliminating free radicals, thus weakening the catalytic reaction of oxidation of L-dopa.

In this work, we propose a new direction of stock index movement prediction algorithm, coined the Ada-ANN forecasting model, which exploits AdaBoost theory and ANN to fulfill the predicting task. ANNs are employed as the weak forecasting machines to construct one strong forecaster. Technical indicators from Chinese stock market and international stock markets such as S&P 500, NSADAQ, and DJIA are selected as the predicting independent variables for the period under investigation. Numerical results are compared and analyzed between strong forecasting machine and the weak one. Experimental results show that the Ada-ANN model works better than its rival for predicting direction of stock index movement.

Rubber sealing components are significant proportion in evaluation of the storage length for production using it. It is necessary to determine and prolong the storage life of production that evaluated the storage length of rubber sealing components accurately. Based on artificial accelerated thermal ageing tests at five levels of temperature, conclude that the storage length of silicon rubber 3S-60 sealing components would be 11.6 years at 25°C and the confidence level of 95%. Validated this conclusion with nature weathering tests results at Jiangjin exposure field in two years, artificial accelerated thermal ageing tests presented here were available. It was illuminated that the storage length evaluation of rubber sealing components should be testified by nature weathering tests results effectually.

Two new oleanane-type triterpene saponins, identified as 16α-hydroxy-22-O-angeloyl-23-formyl-28,31-dihydroxymethylene-olean-12-ene-3β-O-{β- d -galactopyranosyl-(1 → 2)[β- d -xylopyranosyl-(1 → 2)-α- l -arabinopyranosyl(1 → 3)]-β- d -glucopyranosiduronic acid} (oleiferasaponin B1, 1) and 22-O-hydrocinnamoyl-23-formyl-28-dihydroxymethylene-olean-12-ene-3β-O-{β- d -glucopyranosyl-(1 → 2)[β- d -xylopyranosyl-(1 → 2)-α- l -arabinopyranosyl(1 → 3)]-β- d -glucopyranosiduronic acid} (oleiferasaponin B2, 2), were isolated from the seed cake of Camellia oleifera Abel. Their structures were established by extensive 1D- and 2D-NMR experiments along with TOF-MS analysis and acid hydrolysis. The cytotoxicity of the isolated compounds was evaluated in four human carcinoma cell lines: A 549, SK-OV-3, SK-MEL-2 and HCT15. Both compounds 1 and 2 exhibited significantly cytotoxic activity with IC50 values of 18.5 μM (A549), 11.3 μM (SK-OV-3), 13.9 μM (SK-MEL-2) and 1.6 μM (HCT15) for 1 and IC50 values of 8.4 μM (A549), 6.3 μM (SK-OV-3), 9.2 μM (SK-MEL-2) and 0.8 μM (HCT15) for 2. In addition, compound 2 showed more effective cytotoxic activity than compound 1.

The weight of evaluation index plays a key role in condition assessment and maintenance control of power transformer. A new approach of determination of comprehensive weight is proposed in this paper. The approach combines the entropy objective weight with the expert subjective weight together in a specific form, which not only avoids the situation that single weight determines the overall weight, but considers the primary and secondary problem between the two weights. The comprehensive weight calculated by this approach can reflect the place of every index in condition assessment of power transformer well. Empirical results show that the approach is reasonable and available.

Physicochemical properties of No.1 - No.6 lacquer berries were investigated from different origins. The Japan Showafuku (No.1) was the best cultivar of Rhus succedaneum, the size of the berry of it was near 3 - 4 folds, which was bigger than the Chinese cultivars (No.4 - No.6) of Rhus vernicifera et al. It had more than 5% ~ 10% of lacquer wax in pericard, and contained less than 6% - 8% of lacquer oil in seed. No.1 had lower acid value (A.V) and iodine value (I.V); the key factors for this were cultivar and its growing environment. The principal constituents of lacquer waxes of No.1 - No.6 were triglycerides of fatty acids with total saturated fatty acids (TSFA) of 75% - 82.7%, total unsaturated fatty acids (TUSFA) of 15.1% - 20%, and total dibasic acids (TDBA) of 5%. The CIEL a b system and Hunter whiteness formula were used to evaluate the bleaching effect on lacquer wax by physical adsorption and ultraviolet (UV) irradiation. The optimal conditions of physical decoloration were determined for activated carbon: kieselguhr = 3:2 (g/g) as adsorbent, a ratio of 1:20 (g/mL) for lacquer wax to petroleum ether, bleaching 30 min at 80?C. UV light achieved a good bleaching effect irradiated at 60?C for 60 hrs. UV irradiation definitely changed relative contents of fatty acids, TUSFA and TDBA decreased from 19.617% to 11.022% and 4.379% to 2.017% respectively, while TSFA could be raised from 76.462% to 86.077%, however, the mechanism of UV irradiation was still unclear and should be investigated in the future.

Background Polyprenol is an important lipid with many bioactive effects. The study on differences in bioactive effects of polyprenol derivatives having different isoprene units are seldom reported and it is helpful to find out which type of polyprenol derivatives are effective for treating A549/HepG2 cells and E. coli /S. aureus. Methods All tested polyprenol derivatives were measured with inhibition halos by Oxford cup assays. MIC values were assessed by the broth dilution method. Time-killing curve studies were conducted in duplicate on separate days. Cytotoxicity study was measured by the MTT assay and genotoxic study was evaluated by comet assay. Results With regard to antibacterial activity, the sensitivities to the quaternary polyprenyl ammonium salt derivatives GAS and MAS were 31.3 μg/mL and 15.6–31.3 μg/mL, respectively. GAS and MAS exhibited cytotoxic activity toward HepG2 cells (IC50 of 10.1–11.6 μg/mL), which was stronger than that exhibited toward A549 cells (IC50 of 13.8–13.9 μg/mL). The bactericidal activity of MAS was stronger than that of GAS at the same concentration at least 48 h. The DNA damage in A549 and HepG2 cells exposed to all 10, 20 and 40 μg/mL MAS was statistically significant in comparison to the control. Our results indicate a dose-dependent increment in DNA damage in A549 and HepG2 cells exposed to 10, 20 and 40 μg/mL MAS for both the percentage of DNA in the tail and tail moment. Conclusion The quaternary ammonium salt derivatives GAS and MAS exhibited higher antibacterial (E. coli and S. aureus) and cytotoxic activity (A549 and HepG2 cells) than the other derivatives evaluated in this study. The DNA damage in HepG2 cells suggests that MAS induced A549 and HepG2 cells death via apoptotic pathway. Our results provide new evidence supporting the medical use of polyprenol derivatives against bacterial and tumor diseases.

Experiments were conducted to compare the efficacy of montmorillonite (M) and montmorillonite nanocomposite (MN) to reduce the toxicity of aflatoxin (AF) in growing/finishing pigs. A total of 144 weaned pigs were assigned to six dietary treatment groups (0 g of adsorbents and 0 mg of AF/kg feed; 3 g of M/kg feed; 3 g of MN/kg feed; 0.11 mg of AF/kg feed; 0.11 mg of AF plus 3 g of M/kg feed; and 0.11 mg of AF plus 3 g of MN/kg feed). Compared to the control, AF alone decreased average daily gam (ADG) by 12.9% (P 0.05). AF intake increased relative weights of liver, kidney, spleen and pancreas by 8.24, 27.3, 41.2 and 42.9% (P < 0.05), and resulted in significant alteration...

This paper presents an investigation to improve the design of a generic fin heat exchanger, using novel discrete adjoint solver tools in the computational fluid dynamics (CFD) software FLUENT. A baseline design is analyzed initially to evaluate flow resistance and heat transfer. Optimization is conducted by deploying the adjoint solver. The heat load and the drag force are combined into an objective function using a Reynolds analogy approach. Sensitivities of the objective function to geometric changes are predicted by the adjoint, and then the mesh is morphed, and the predictions are verified by the full CFD solutions. Predetermined, engineering driven, geometric changes are explored and compared, and the range of validity of the predictions is evaluated. An algorithm is then developed to implement steepest descent, constrained optimization based on the adjoint solution. The algorithm is applied iteratively on the fin heat exchanger, and a comparison is performed between the change in objective function predicted by the adjoint, and that calculated in full CFD solutions on morphed meshes. The insight gained on the directions of design changes and attending quantitative improvement of the design objective function is very useful to guide the optimization process. This is enabled by the adjoint solver’s capability to robustly evaluate the sensitivities of the objective function to all solution variables, and predict changes in observables.Copyright © 2015 by ASME

In order to choose suitable varieties with high yield and good quality for cultivation, 10 lucerne varieties, including six foreign ones ('WL‐525HQ’, ‘WL‐414’, ‘WL‐323’, ‘Italian’ lucerne, ‘Sitel’, and ‘Vernal') and four domestic ones ('Wudi’ lucerne, ‘Aohan’, ‘Zhongmu No.1’, and ‘Inner Mongolian’ lucerne), were studied in Zhengzhou, Henan Province, China, in 2001 and 2002 using a randomised block design with three replications. Each plot was cut four or five times each year over the 2‐year period to evaluate herbage production of the tested varieties. ‘WL‐525HQ’, ‘Sitel’, and ‘WL‐414’ were the best, with relatively high plant height, large leaf/stem ratio, and dry matter herbage yield. Cutting times had a significant effect on dry matter herbage yield, with the highest yield in the first cut and the lowest in the fifth. Correlation analyses showed that plant height was significantly positively related with dry matter herbage yield. Close relationships were found among annual dry matter herbage y...

Three high purified polysaccharide monomers (GBP11, GBP22, and GBP33) were obtained from enzymatic hydrolysate of Ginkgo biloba leave using DEAE-Sepharose Fast Flow column and Sephadex G-100 column, and their basic structural characterization were investigated by utilizing high-performance liquid chromatography, high-performance ion chromatography, and Infrared Spectroscopy. In addition, antioxidant activities of related polysaccharides were also evaluated. The results showed that the molecular weight of GBP11, GBP22, and GBP33 were 1.944 × 103 KDa, 5.167 × 103 KDa, and 45.98 KDa, singly, and they were mainly made up of glucose, galactose, arabinose, and rhamnose with a molar ratio of 62.2:1.98:3.84:1.24, 3.57:68.0:4.67:0.36 and 5.34:48.8:1.70:8.97, respectively. Moreover, GBP22, GBP, and GBP11 demonstrated the strongest free radical scavenging activity on DPPH, ABTS, and superoxide anion, showing that they have potential application value on the functional food and cosmetic industry. Practical applications Enzymatic hydrolysate of Ginkgo biloba leaves includes lots of carbohydrate, it will cause eutrophication and environment pollution if it is directly poured out. This research indicates that carbohydrate extracted from enzymatic hydrolysate of Ginkgo biloba leaves are made up of different polysaccharide monomers with various molecular weight and monosaccharide composition. Moreover, these polysaccharide monomers possess appreciating antioxidant activities. Therefore, this research could lay a foundation for the high-value application of polysaccharides in functional food and cosmetic industry, and provide theoretical reference for the treatment of waste water.

Solvent extracts of Rhus verniciflua Stokes wood were made using decompressing inner ebullition, and a Box-Behnken design was used to optimize extraction conditions to produce an extract that inhibited tyrosinase activity. The chemical compositions and inhibition rates were determined in extracts made with petroleum ether, ethyl acetate, n-butanol, and an aqueous fractionation. The ethyl acetate fraction had the highest total phenolic content and inhibition rates. The main flavonoids in this fraction were 0.531% fisetin, 7.582% fustin, 0.848% sulfuretin, and 0.272% butein. The effects of the extract on the monophenolase and diphenolase activity of mushroom tyrosinase were studied using the Lineweaver-Burk equation to determine the effect of the extract on inhibition of tyrosinase activity. The results showed that the extract inhibited both the monophenolase and diphenolase activity of the enzyme. The IC50 of the ethyl acetate extract was 308 μg/mL, with the lag period of the enzyme being obviously lengthened; it was estimated to be 2.45 min in the absence of the inhibitor and extended to 9.63 min in the presence of 500 μg/mL of extract. The ethyl acetate extract acted as a mixed type inhibitor. The KI was less than the KIS, which demonstrates that the [ESI] is less stable than [EI], suggesting that the extract could easily combine with free enzyme in the enzyme catalysis system, thus affecting enzyme catalysis on the substrate.

First-principles density-functional linearized augmented plane-wave linear-response calculations are presented of the lattice dynamics of tetragonal ${\mathrm{La}}_{2}{\mathrm{CuO}}_{4}.$ Phonon frequencies and eigenvectors are obtained throughout the Brillouin zone. Generally good agreement is achieved with experiment, but frequencies of the lowest-lying branches, which involve anharmonic motion of the apical oxygen atoms parallel to the ${\mathrm{CuO}}_{2}$ planes, are underestimated. The octahedral tilt mode at the X point is found to be the most unstable mode throughout the Brillouin zone, consistent with the observed phase transition to the orthorhombic structure at low temperature. The calculated dispersion of the highest frequency ${\ensuremath{\Sigma}}_{3}$ branch is in good agreement with experiment, showing that a proposed large renormalization of the phonon spectrum by a Jahn-Teller electron-phonon interaction is unlikely.

Molecular dynamics simulations of the perovskite oxide KNbO3 are performed with a first-principles effective Hamiltonian. They reveal the prevalence of local polar distortions with short-range chain-like correlations, present even in the paraelectric phase far above Tc. The ordering of these dynamically fluctuating distortions yields the observed temperature sequence of ferroelectric phases. The simulations also reproduce the essential features of diffuse x-ray scattering measurements and the weak temperature dependence of diffuse streak patterns observed by Comes et al. These local distortions suggest an order-disorder character for the transitions. Softening of optical phonon branches is observed in the same simulations not only near q = 0, suggesting a displacive character for the transition, but also over large regions of the Brillouin zone. Dynamic real-space chains thus provide a unified framework for understanding both the order-disorder and displacive characteristics of these phase transitions.

First principles calculations were performed for the structural properties of superhard materials, hexagonal β-Si3N4, β-C3N4, and two model structures of β-Si2CN4 and β-SiC2N4. Bulk modulus and lattice constants a and c have been obtained by fitting the total energy calculations to the Birch equation of state. As more C atoms are substituted for Si in β-Si3N4, the bulk modulus is observed to progressively increase up to 4.44 Mbar, comparable to that of diamond (4.43 Mbar), and both lattice constants a and c are reduced. For β-Si3N4 and β-C3N4, the lowest energy geometries have been searched by optimizing the internal structural parameters at the theoretical equilibrium lattice constants. The results are discussed and compared with available experiments.

We performed first principles LAPW linear response calculations for KNbO3 in the cubic, experimental tetragonal, and theoretical ground state rhombohedral structures. We found that the Born effective charges and dielectric constants strongly depend on the small atomic displacements involved in the ferroelectric phase transitions. We also calculated the zone center phonons for the cubic structure and compared them with previous LDA results.

In order to make the dark green pigments fade away and broaden the appliance of lacquer wax, both physical adsorption and ultraviolet (UV) irradiation were optimized and further compared in this paper. The optimal conditions of physical discoloration could be achieved in 80 °C when 20 mL petroleum ether blends with 1 g raw wax assisted by 5 % activated carbon/kieselguhr (1:1, m/m) as an adsorbent for 30 min, twice. A good bleaching effect of lacquer wax of UV radiation can be reached in 60 °C for 60 h. The CIEL*a*b* system and Hunter whiteness formula were used to evaluate the discoloration effect. The value of peroxide, iodine, acid, and relative contents were imported to present the physical–chemical characterizations alteration. The chemical constituents variation of lacquer wax during the discoloration process was detected by GC-MS analyzer. A sharp increase of whiteness (by 54 %) occurred after these two processes and insignificant decrease in physical–chemical qualities indicated an effective and specificity method.

Polyprenols are new effective lipids separated from Ginkgo biloba L. leaves. In this paper, the light and heavy distillates were prepared from ginkgo lipids by extraction with petroleum ether, saponification, and molecular distillation. And then the seven known compounds: β-sitosterol acetate (1), palmitamide (2), glyceryl tripalmitate (3), β-sitosterol-3-O-β-d-glucopyranoside (4), β-sitosterol (5), stigmasterol (6), ergosterol (7), and polyprenols were isolated by chromatograph from lipids of Ginkgo biloba L. leaves. In the meantime, the antibacterial activity of light and heavy distillates, seven compounds and polyprenols was assessed against three pathogenic strains (Staphylococcus aureus, Escherichia coli, and Bacillus subtilis) employing disc-diffusion and broth-dilution assays. The heavy distillates showed the highest activity (zone of inhibition of 14–17 mm) followed by the light distillates (13–15 mm), polyprenols (12–14 mm), β-sitosterol (5) (10–14 mm), palmitamide (2) (11–13 mm), β-sitosterol-3-O-β-d-glucopyranoside (4) (10–13 mm), β-sitosterol acetate (1) (10–12 mm), stigmasterol (6), and ergosterol (7) (9–10 mm), glyceryl tripalmitate (3) (10 mm) at 500 μg/mL. MIC and MBC values for the bacteria sensitive to polyprenols were in the range of 31.3–62.5 μg/mL and 125 μg/mL. It can be inferred polyprenols which have synergistic inhibitory effect with other lipids.

Numerical simulations of turbine rim seal experiments are conducted with a time-dependent, 360 deg computational fluid dynamics (CFD) model of the complete turbine stage with a rim seal and cavity to increase understanding of the rim seal ingestion physics. The turbine stage has 22 vanes and 28 blades and is modeled with a uniform flow upstream of the vane inlet, a pressure condition downstream of the blades, and three coolant flow conditions previously employed during experiments at Arizona State University. The simulations show the pressure fields downstream of the vanes and upstream of the blades interacting to form a complex pressure pattern above the rim seal. Circumferential distributions of 15 to 17 sets of ingress and egress velocities flow through the rim seal at the two modest coolant flow rate conditions. These flow distributions rotate at approximately wheel speed and are not equal to the numbers of blades or vanes. The seal velocity distribution for a high coolant flow rate with little or no ingestion into the stator wall boundary layer is associated with the blade pressure field. These pressure field characteristics and the rim seal ingress/egress pattern provide new insight to the physics of rim seal ingestion. Flow patterns within the rim cavity have large cells that rotate in the wheel direction at a slightly slower speed. These secondary flows are similar to structures noted in previous a 360 deg model and large sector models but not obtained in a single blade or vane sector model with periodic boundary condition at sector boundaries. The predictions of pressure profiles, sealing effectiveness, and cavity velocity components are compared with experimental data.

The Born effective charge ${\mathrm{Z}}^{\mathrm{*}}$ and dielectric tensor ${\mathrm{\ensuremath{\epsilon}}}_{\mathrm{\ensuremath{\infty}}}$ of ${\mathrm{KNbO}}_{3}$ are found to be very sensitive to the atomic geometry, changing by as much as 27% between the paraelectric cubic and ferroelectric tetragonal and rhombohedral phases. Subtracting the bare ionic contribution reveals changes of the dynamic component of ${\mathrm{Z}}^{\mathrm{*}}$ as large as 50%, for atomic displacements that are typically only a few percent of the lattice constant. ${\mathrm{Z}}^{\mathrm{*}}$, ${\mathrm{\ensuremath{\epsilon}}}_{\mathrm{\ensuremath{\infty}}}$, and all phonon frequencies at the Brillouin zone center were calculated using the ab initio linearized augmented plane-wave linear response method with respect to the reference cubic, experimental tetragonal, and theoretically determined rhombohedral ground-state structures. The ground-state rhombohedral structure of ${\mathrm{KNbO}}_{3}$ was determined by minimizing the forces on the relaxed atoms. In contrast to the cubic structure, all zone-center phonon modes of the rhombohedral structure are stable, and their frequencies are in good agreement with experiment. In the tetragonal phase, one of the soft zone-center modes in the cubic phase is stablized. In view of the small atomic displacements involved in the ferroelectric transitions, it is evident that not only the soft-mode frequencies but also the Born effective charge and dielectric constants are very sensitive to the atomic geometry. \textcopyright{} 1996 The American Physical Society.

First principles LAPW linear response calculations of the lattice dynamics of cubic KNbO 3 reveal planar instability in the Brillouin zone. In real space, these correspond to chains along the 〈100〉 directions of Nb atoms coherently displaced along the chain direction. Zone-center calculations in the rhombohedral phase yield stable modes (and no unusually soft modes) consistent with experiment. The similarity of the ferroelectric phases in BaTiO 3 suggests such chain instabilities also occur. It is likely that the ferroelectric phase transitions in these materials will depend on the dynamics of such chains.

Numerical simulations of turbine rim seal experiments are conducted with a time-dependent, 360-degree CFD model of the complete turbine stage with a rim seal and cavity. The turbine stage has 22 vanes and 28 blades and is modeled with a uniform flow upstream of the vane inlet, a pressure condition downstream of the blades and three coolant flow conditions previously employed during experiments at Arizona State University. The simulations show the pressure fields downstream of the vanes and upstream of the blades interacting to form a complex pressure pattern above the rim seal. Circumferential distributions of 15 and 17 sets of ingress and egress velocities flow through the rim seal at the two modest coolant flow rate conditions. These flow distributions rotate at wheel speed and are not associated with the numbers of blades or vanes. The seal velocity distribution for a high coolant flow rate with little or no ingestion into the stator wall boundary layer is associated with the blade pressure field. These pressure field characteristics and the rim seal ingress/egress pattern provide new insight to the physics of rim seal ingestion. Flow patterns within the rim cavity have large cells that rotate in the wheel direction at a slightly slower speed. These secondary flows are similar to structures noted in previous a 360-degree model and large sector models but not obtained in a single blade or vane sector model with periodic boundary condition at sector boundaries. The predictions of pressure profiles, sealing effectiveness and cavity velocity components are compared with experimental data.

CuCl is known to exhibit large anharmonic effects and possibly a complicated multiwell Born-Oppenheimer surface reminiscent of the instabilities in perovskite ferroelectrics and cuprate superconductors. However, we have determined its phonon dispersion from first principles calculations and find it to agree well with low temperature experimental results. The calculations were carried out using a linear response formalism based on the linearized augmented plane wave method within the local density approximation. The calculated Born effective charges are within 10% of experiment and the high frequency dielectric constant ${\mathrm{\ensuremath{\epsilon}}}_{\mathrm{\ensuremath{\infty}}}$ is about 30% larger than the experimental value. This level of agreement is comparable to that attained in simpler semiconductors.

At present, extracted gastric motility features indices include impedance gastric motility (IGM) and EGG is an important way to understand erosive gastritis (EG). Methods: According the clinic standardization, 30 volunteers of erosive gastritis were selected. Both signals impedance gastric motility (IGM) and EGG collected from body surface are decomposed by Multi-resolution Analysis (MRA). the MRA can help us calculate the frequency of EGG and IGM signal power spectrum and dynamic spectrum, the rates of rhythm and power for the normal EGG and IGM and so on. Wavelet transform is addressed to separate the IGM signal from breathing and blood flowing impedance signals. Results: After a week of testing discovered patients with health adult (p

This Multi-parameter system was designed to monitor depth of Anaesthesia (DOA) for children surgical intervention. Three signals: ECG especially Heart rate variability (HRV) contained, Pressure of End-Tidal Carbon Dioxide (PETCO2) and Oxygen Saturation (SPO2) were used to evaluate depth of anaesthesia. Results show that the system can extract the signals clearly and reflect the change of signals feasible and reliable. The monitoring system can not only be used during the surgical, but also monitor the patient after surgical.

The hepatoprotective effects of polyprenols from Ginkgo biloba L. leaves were evaluated against carbon tetrachloride induced hepatic damage in Sprague–Dawley rats. The elevated levels of serum ALT, AST, ALP, ALB, TP, HA, LN, TG, and CHO were restored towards normalization significantly by GBP in a dose dependent manner. The biochemical observations were supplemented with histopathological examination of rat liver sections. Meanwhile, GBP also produced a significant and dose-dependent reversal of CCl4-diminished activity of the antioxidant enzymes and reduced CCl4-elevated level of MDA. In general, the effects of GBP were not significantly different from those of the standard drug Essentiale.

To investigate the molecular mechanism underlying the effect of linoleic acid on plasminogen activator inhibitor type-1 (PAI-1) expression in HepG2 cells.HepG2 cells were exposed to different concentrations of linoleic acid and PAI-1 expression was determined by RT-PCR and colorimetric assay. Luciferase reporter gene plasmids containing four sequentially truncated fragments of the PAI-1 promoter region (-804 to +17) were constructed, and plasmids carrying constructs of Smad binding element (SBE)-site directed deletions in PAI-1 promoter were also generated using overlap extention PCR and transiently transfected into HepG2 cells, the transcriptional activity of PAI-1 was demonstrated by the luciferase activity.The effect of linoleic acid on Smad3 and Smad4 protein levels in cultured HepG2 cells was measured by Western blot analysis.(1) Linoleic acid remarkably increased PAI-1 mRNA expression and transcription in varying concentrations. (2) The level of PAI-1 transcription was gradually decreased induced by linoleic acid when transfected the SBE- site directed-deletions plasmids in PAI-1 promoter at -734/-731. (3) Protein levels of both Smad3 and 4 in HepG2 cells were increased by linoleic acid.Linoleic acid regulated the expression of PAI-1 from transcriptional level in HepG2 cells and SBE involved in the regulation, and both Smads protein and Smad signaling pathway acted main role in this procession.

Experiments were carried out in a model air turbine stage to study the influence of rotor-stator rim cavity configuration on the ingestion of mainstream gas into the cavity. The three rim cavity configurations differed in their aspect ratio (height/width); the rim seal geometry remained the same. The aspect ratio was changed from the baseline ratio by installing an inner shell on the stator at an appropriate radius; this effectively introduced an axial-gap seal between the rim cavity and the cavity radially inboard. The initial step in each experiment was the measurement of time-average static pressure distribution in the turbine stage to ascertain that proper flow condition had been established. Subsequently, tracer gas concentration and particle image velocimetry techniques were employed to measure the time-average but spatially local main gas ingestion and the instantaneous velocity field in the rim cavity. At low purge air flow, regions of ingestion and egress could be identified by inspecting the instantaneous radial velocity distribution near the rim seal obtained from cavity gas velocity maps close to the stator. While the tangential velocity tended to be slightly larger for the so determined ingested gas, a more clear-cut indicator of ingestion was the strong inward gas radial velocity. Information provided by ensemble-average velocity maps was not sufficient for identifying ingestion because the averaging smeared out flow details, which varied from instant to instant. Velocity fields obtained from three-dimensional, time-dependent numerical simulation of a rim seal-cavity sector with similar dimensions qualitatively showed similar characteristics in the outer part of the cavity and provided insight into the complex flow in the seal region.

Rim seal ingestion models for gas turbines are formulated to estimate the amount of hot fluid ingested through “clearance” seals into the disk cavity. Previous numerical and experimental studies showed the complex time-dependent, three-dimensional characteristics of the flow through the seals and in the outer region of the disk cavity. The present model is developed for estimating ingress and egress flow through the seal that is driven by the azimuthal variation in gas path pressure near the vane and blade platforms. Most published rim seal orifice models have used one “lumped parameter” Cd for both ingress and egress across the seal. However, the flow path from the gas path through the seal is often more convoluted than the flow returning to the gas path. The present Rim Seal Orifice Model includes (i) a Cd value for ingress from the gas path into the disk cavity, (ii) a Cd value for egress from the disk cavity to the gas path and (iii) an estimate for effects of swirl from the seal outer radius to the inner radius of the seal mixing region. The use of two Cd values provides two parameters for characterizing the flow through the seal. The ingress and egress Cd values for a turbine rim seal configuration and flow condition are estimated by comparing the modeled seal effectiveness for a parametric range of ingress and egress Cd values with experimental stator wall measurements. The combination of Cd values, which best matches experimental data over a range of coolant flow ratios, characterizes the seal and flow condition. Arizona State University experimental data were used to estimate the Cd values for an overlap seal configuration.

The ingestion of mainstream gas into turbine rotor-stator disk cavities and simultaneously, the egress of cavity gas into the main gas path are consequences of the prevailing unsteady, three-dimensional flow field. To understand these processes, we are carrying out a study that combines experiments in a model single-stage axial turbine with computational fluid dynamic (CFD) simulations. The turbine stage features vanes, blades, and axially overlapping radial clearance rim seal. In this paper, we present time-resolved velocity maps, obtained by particle image velocimetry, of the flow in the disk cavity at four experimental conditions as defined by the main air flow rate, rotor speed, and purge air flow rate. Time-averaged but spatially local measurement of main air ingestion is also presented. Significant ingestion occurred at two of the four experimental conditions where the purge air flow rate was low — it is found that high tangential (swirl) velocity fluid intersperses with lower tangential velocity fluid in the rim region of the cavity. It is argued that the high tangential velocity fluid is comprised of the ingested main air, while the lower tangential velocity fluid is the indigenous cavity air. This interpretation is corroborated by the results of the unsteady, three-dimensional CFD simulation. When the purge flow rate was high, no ingestion occurred as expected; also, large-scale structures that were unsteady appeared in the cavity flow giving rise to large velocity fluctuations. It is necessary to obtain time-resolved information from experiments and computation in such a flow because even when the vane-blade relative position is matched during a particular experiment, the instantaneous flow field does not necessarily remain the same. As such, some of the flow patterns will be smeared out if the interrogation time scale is large.Copyright © 2007 by ASME

3D unsteady computational fluid dynamics analyses were performed for both close-spaced and wide-spaced turbine stages with axial gap seals and a cavity. Turbine stages, with airfoil configurations similar to those previously studied at United Technologies Research Center (UTRC) and Arizona State University (ASU), were simulated for vane-blade spacing at 34 percent and 70 percent of the vane axial chord length, L. Three configurations were investigated, with the first one placing an axial gap rim seal at 17 percent L upstream of the blade for close-spaced stage, and the other two placing the axial gap seal at either 17 or 34 percent L upstream of the blade for the wide-spaced stage. The seal velocity ingestion characteristics were strongly dependent on axial location for the wide-spaced stage. The seals placed at equal distances upstream of the blade leading edge for the wide- and close-spaced stages had approximately the same average ingestion velocity characteristics. However, the ingestion velocity profiles for the wide-spaced stage were less influenced by vane wakes than for the close-spaced stage. The calculated variation of radial velocity in all gaps was consistent with previous tangential and radial velocity measurements in the seal gap measurements at the University of Aachen.Copyright © 2007 by ASME

Current and future gas turbine engines are subject to increasing performance requirements and improved fuel efficiencies. The resultant engine cycles increase core flow temperatures requiring additional cooling flow while requiring a reduction in parasitic leakage by 25%–50% to meet the performance goals. The achievement of the reduced leakage requires that seal design concepts be tested and improvements validated in engine like conditions before they are introduced into the gas turbine product. This paper describes the process of how a potentially low leakage seal design was evaluated and tested in an advanced seal test rig facility. How existing engine seal leakage rig data was used to validate physics based models (CFD) of baseline labyrinth seal configurations, then used to run back to back sensitivity studies to identify seal design characteristics that could provide low leakage seal designs. The paper discusses the use of an Advanced Seal Rig (ASR) facility to test seal design concepts for gas turbine engine applications. Test seal flow results are presented and compared to the base line seal tests. The differences between the new seal design flow test results and the base line seal flow test results are investigated. Further, seal test flow results are compared with the validated physics based model predictions (CFD) run at the advanced seal rig test conditions. Differences between rig data and analysis are discussed. Future seal testing and analysis work is suggested.Copyright © 2006 by ASME