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Needles of Juniperus rigida are used in Chinese traditional medicine for the treatment of brucellosis, dropsy, skin disease, and rheumatoid arthritis. This is the first study that reports anatomical structures of the J. rigida needles collected at different altitudes. The most common anatomical, phytochemical, and histochemical techniques and methods are used. The results show that anatomical structures and chemical composition change significantly at different altitudes. The main anatomical characters are significant xeromorphic structures (thick epidermis, hypodermis, and cuticle), a stomatal band, a developed vascular bundle, and a marginal resin duct. The xeromorphic structures become more pronounced with increasing altitude. The phytochemical and histochemical results demonstrate that the content of the main chemical compounds (phenols and terpenoids) basically increases at a higher elevation. Histochemical analysis localizes the phenols in epidermal cells, sponge tissue, endothelial layer cells, and stomatal bands, and the terpenoids in palisade tissue, sponge tissue, and the edge of the resin duct. This work reveals the relation between anatomy and chemistry in J. rigida needles, contributes to the quality control of its ethno-medicine, and provides the evidence to develop the commercial cultivation.
This work focuses on the application of nanoindentation measurements and the finite element method for analyzing the mechanical properties of the rostrum of the outstanding driller Cyrtotrachelus buqueti Guer. Nanoindentation tests were carried out to measure the Young's modulus and hardness of the rostrum, with the results for the “dry” samples being 13.886 ± 0.75 and 0.368 ± 0.0445 GPa, respectively. The values for the “fresh” samples showed no clear difference from those of the “dry” ones. Moreover, field observation was conducted to determine the motion behaviors of the rostrum on the weevil. Micro-computed tomography technology was employed to obtain structural information about the rostrum, using 9 µm slices. A real three-dimensional model of the rostrum was created using the MIMICS application. Finally, the mechanical properties of the rostrum were determined by finite element analysis. It was concluded that the rostrum provides an ideal biological template for the design of biocomposite materials and lightweight tube-shaped structures. The properties determined in this study can potentially be applied in different fields, such as in the design of automotive hybrid transmission shafts, helicopter tail drive shafts, robotic arms, and other sandwich structures in aerospace engineering.
The consequences of urbanisation for Earth's biogeochemical cycles are largely unexplored. Copper (Cu) in urban soils is being accumulated mainly due to anthropogenic activities under rapid urbanisation. The increasing Cu concentrations may contribute to altering soil nitrogen (N) cycling in urban ecosystems through modulating denitrification processes. This research aims to identify how Cu impacts urban soil denitrification functions and denitrifier abundance. An urban park soil with a background total Cu concentration of 7.9μgg–1 was incubated anaerobically with different Cu amendments (10, 20, 40, 80 and 160μg Cu g–1 soil), similar to prevalent Cu contents in urban soils. We evaluated the soil denitrification functions using the acetylene (C2H2) inhibition method and assessed the denitrifier abundance by quantitative polymerase chain reaction (qPCR) analyses of denitrifying marker genes (nirK, nirS and nosZ). At the function level, we observed that both the potential soil denitrification activity and the N2O emission rate due to denitrification were significantly (P<0.05) inhibited by Cu; even the lowest Cu addition (10μg Cu g–1 soil) drastically affected the denitrification function. Moreover, Cu significantly (P<0.05) decreased the abundance of nirK and nirS genes at the additions of 160μg Cu g–1 soil and 40μg Cu g–1 soil, respectively, whereas it had no clear impact on nosZ gene copies. Further correlation analyses revealed that the potential denitrification activity was positively correlated to the copy numbers of nirK and nirS genes, but it was not correlated to nosZ gene abundance. These findings indicate that Cu additions inhibited soil denitrification function and decreased denitrifier abundance in the investigated urban park soil. Our results suggest that Cu accumulation in urban soils, resulting from urbanisation, may generally influence denitrification in urban ecosystems.
Partial differential equations are powerful tools for used to characterizing various physical systems. In practice, measurement errors are often present and probability models are employed to account for such uncertainties. In this paper we present a Monte Carlo scheme that yields unbiased estimators for expectations of random elliptic partial differential equations. This algorithm combines a multilevel Monte Carlo method (Giles (2008)) and a randomization scheme proposed by Rhee and Glynn (2012), (2013). Furthermore, to obtain an estimator with both finite variance and finite expected computational cost, we employ higher-order approximations.
This article describes a new method by which azimuth and the instantaneous latitude of a meridian-prime vertical-transit instrument can be determined absolutely in mid-and low- latitude areas, and discusses some experimental observations obtained on a remodeled ZEISS transit instrument. Requirements for the development of a new type of transit circle along the lines of this new method are also presented.
Field surveys indicate that host population size, rather than density, is the most important determinant of monogenean infection dynamics. To verify this prediction, epidemic parameters were monitored for 70 days at five host population sizes held at constant density using a goldfish – Gyrodactylus kobayashii laboratory model. During the first 20 days, the rate of increase of prevalence and mean abundance was faster in small host populations. Total mean prevalence and total mean abundance throughout the experiment were not significantly affected by host population sizes. Higher transmission rates were detected in larger host populations. However, there were no significant differences in effective contact rates among the five host populations on each sampling day during the first 20 days, implying that contact rates may be saturated at a sufficiently high host density. These results demonstrate that the epidemic occurs more quickly in smaller host populations at the beginning of the experiment. However, the epidemic is independent of the host population size due to the similar effective contact rates in the five population sizes. Significant negative influence of the initial body condition (Kn) of uninfected goldfish on total mean abundance of parasites suggests that susceptibility of hosts is also a determinant of parasite transmission.
Phase stability, elastic, and thermodynamic properties of (Co,Ni)3(Al,Mo,Nb) with the L12 structure have been investigated by first-principles calculations. Calculated phonon density of states show that (Co,Ni)3(Al,Mo,Nb) is dynamically stable, and calculated elastic constants indicate that (Co,Ni)3(Al,Mo,Nb) possesses intrinsic ductility. Young’s and shear moduli of the simulated polycrystalline (Co,Ni)3(Al,Mo,Nb) phase are calculated using the Voigt–Reuss–Hill approach and are found to be smaller than those of Co3(Al,W). Calculated electronic density of states depicts covalent-like bonding existing in (Co,Ni)3(Al,Mo,Nb). Temperature-dependent thermodynamic properties of (Co,Ni)3(Al,Mo,Nb) can be described satisfactorily using the Debye–Grüneisen approach, including heat capacity, entropy, enthalpy, and linear thermal expansion coefficient. Predicted heat capacity, entropy, and linear thermal expansion coefficient of (Co,Ni)3(Al,Mo,Nb) show significant change as a function of temperature. Furthermore the obtained data can be used in the modeling of thermodynamic and mechanical properties of Co-based alloys to enable the design of high temperature alloys.
In traditional antenna design, metal components are not placed in the central part of the antenna as they change the characteristics of near field radiation. However, we show that placing a metal ring in the centre of the strip lines, which connect the ends of folded high-frequency dipoles, does not damage the performance of the feed. Instead it significantly improves the voltage standing wave ratio of the feed whilst other performance indicators are not compromised. Thus, our findings show an excellent way of improving the wide band feed. Based on this foundation, a new circularly polarised feed for operation between 0.4 to 2 GHz is introduced for the Chinese Spectral Radioheliograph in this paper. The issue of a feed impedance matching network is investigated. By optimising the impedance matching, the performance of the feed is enhanced with respect to the previous realisations of the Eleven feed. The simulation and experimental results show that the gain of the feed is about 10 dBi, and the VSWR is less than 2:1. In addition, the feed has a low axial ratio, fixed phase centre location, and constant beam width in the range of 0.4 to 2 GHz.
The NCU (National Central University) Lu-Lin observatory is located at Mt. Front Lu-Lin, 120°52′25”E and 23°28′07” N, a 2862-m peak in the Yu-Shan National Park. The construction of Lu-Lin observatory was finished on January 14, 1999. The initial assessment of Lu-Lin site started in 1989, after which a three-year project was founded by the National Science Council (NSC) to support a modern seeing monitoring program. The average seeing at Lu-Lin is about 1.39 arc-second with an average of 200 clear nights annually. The sky background is 20.72 mag/arcsec2 in V band and 21.22 mag/arcsec2 in B band.
The Lu-Lin observatory is for both research and education. A homemade 76-cm Super Light Telescope (SLT) and four TAOS 50-cm robotic telescopes for a survey on Kuiper Belt Objects will be the two major research facilities. The pilot program for SLT consists of observations of time-varying astrophysical phenomena. The TAOS #1 telescope was installed at Lu-Lin in March 2000. A 90 KW/240 VAC power line and a water pipe system have been pulled to the site in early 2001. A wireless Network system through A-Li Shan has been operating at Lu-Lin observatory while a faster wireless Network system with 11.5 Mbit/sec bandwidth is under consideration and may be available in the near future for remote observing.
We evaluated the usefulness of lissamine green B (LB) staining of cumulus–oocyte complexes (COC) as a non-invasive method of predicting maturational and developmental competence of slaughterhouse-derived porcine oocytes cultured in vitro. Cumulus cells of freshly aspirated COCs were evaluated either morphologically on the basis of thickness of cumulus cell layers, or stained with LB, which penetrates only non-viable cells. The extent of cumulus cell staining was taken as an inverse indicator of membrane integrity. The two methods of COC grading were then examined as predictors of nuclear maturation and development after parthenogenetic activation. In both cases LB staining proved a more reliable indicator than morphological assessment (P < 0.05). The relationship between LB staining and cumulus cell apoptosis was also examined. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay for DNA fragmentation revealed that oocytes within COCs graded as low quality by either LB staining or visual morphology showed significantly greater DNA fragmentation (P < 0.05) than higher grades, and that LB and visual grading were of similar predictive value. Expression of the stress response gene TP53 showed significantly higher expression in COCs graded as low quality by LB staining. However expression of the apoptosis-associated genes BAK and CASP3 was not significantly different between high or low grade COCs, suggesting that mRNA expression of BAK and CASP3 is not a reliable method of detecting apoptosis in porcine COCs. Evaluation of cumulus cell membrane integrity by lissamine green B staining thus provides a useful new tool to gain information about the maturational and developmental competence of porcine oocytes.
There are three native varieties of edible yams (Dioscorea japonica Thunb.) in Taiwan, but germplasm has been collected from only a few. To assess the genetic diversity of 99 accessions collected from four geographically diverse regions, inter-simple sequence repeat (ISSR) DNA markers were analysed, and 90.2% of the polymorphic markers in these accessions were found. Genetic similarity among accessions ranged from 30.8 to 74.4%, averaging 48.4%. Cluster analyses revealed four main clusters plus one outlier (Dioscorea alata L.). The varieties oldhamii and pseudojaponica were separated into different clusters and var. japonica was grouped with both varieties. Since var. japonica was found to be genetically similar to var. oldhamii and var. pseudojaponica, we suggest that var. japonica is a hybrid or intermediate variety between the two varieties. Molecular analysis of variance results indicated that variation within counties (95.94%) was predominantly greater than variation among counties (3.63%) and among regions (0.43%). Overall, gene flow (Nm= 0.970) estimated from genetic differentiation (Gst= 0.340) suggests that gene flow among regions is relatively high. The highest genetic diversity (H= 0.191) and Shannon's index (I= 0.312), and a high gene flow (Nm= 3.926) of germplasm in the northern region suggest that this region is a possible centre of dispersal and domestication of yams in Taiwan. This study provided valuable information for germplasm collection and genetic improvement.
The Chinese Spectral Radioheliograph is an aperture-synthesis telescope observing the Sun in ultra wide bandwidth on the ground. It contains two arrays Chinese Spectral Radioheliograph-I and Chinese Spectral Radioheliograph-II from 0.4 to 15 GHz. In order to obtain ultra wide-band performance, the cascaded folded dipoles are used in this feed. At the same time, in order to get circularly polarised signals coming from the Sun, a wide-band 90° hybrid is added in the output ports of the feed. This feed has characteristics of about 10 dBi gain, less than 1.5 voltage standing wave ratio. It also has characteristics with low axial ratio, fixed phase centre location, and constant beam width in operating frequencies. Through cross-correlating all combinations of two orthogonal polarisations at each antenna, the polarisation state of the waves is measured and give a differential instrumental delay between two data channels. The relationship between the own polarisation degree of the Sun and the observed polarisation degree is also measured for cross-polarised delay in observing the Sun in this paper.
The bioavailability of dietary ionised calcium is affected by intestinal basic environment. Calcium-binding peptides can form complexes with calcium to improve its absorption and bioavailability. The aim of this study was focused on isolation and characterisation of a calcium-binding peptide from whey protein hydrolysates. Whey protein was hydrolysed using Flavourzyme and Protamex with substrate to enzyme ratio of 25 : 1 (w/w) at 49 °C for 7 h. The calcium-binding peptide was isolated by DEAE anion-exchange chromatography, Sephadex G-25 gel filtration and reversed phase high-performance liquid chromatography (RP-HPLC). A purified peptide of molecular mass 204 Da with strong calcium binding ability was identified on chromatography/electrospray ionisation (LC/ESI) tandem mass spectrum to be Glu-Gly (EG) after analysis and alignment in database. The calcium binding capacity of EG reached 67·81 μg/mg, and the amount increased by 95% compared with whey protein hydrolysate complex. The UV and infrared spectrometer analysis demonstrated that the principal sites of calcium-binding corresponded to the carboxyl groups and carbonyl groups of glutamic acid. In addition, the amino group and peptide amino are also the related groups in the interaction between EG and calcium ion. Meanwhile, the sequestered calcium percentage experiment has proved that EG-Ca is significantly more stable than CaCl2 in human gastrointestinal tract in vitro. The findings suggest that the purified dipeptide has the potential to be used as ion-binding ingredient in dietary supplements.
It is well established that estrogen and progesterone are critical endogenous hormones that are essential for implantation and pregnancy in females. However, the distribution of estrogen receptor α (ERα) and progesterone receptor (PR) in female reproductive tracts is elusive. Herein, we report that after serial treatments with pregnant mare's serum gonadotrophin (PMSG) with or without anti-PMSG (AP), mice could regulate the distribution of ERα and PR in the murine ovary, oviduct and uterus and the level of estradiol in serum. ERα and PR regulation by PMSG and anti-PMSG was estrous cycle-dependent and critical for promoting the embryo-implantation period. Furthermore, our results suggested that AP-42 h treatment is more effective than the other treatments. In contrast, other treatment groups also affected the distribution of ERα and PR in mouse reproductive tracts. Thus, we found that anti-PMSG has the potential to restore the distribution of ERα and PR, which could effectively reduce the negative impact of residual estrogen caused by the normal superovulation effect of PMSG in mice.
Experimental X-ray powder diffraction data, unit-cell parameters, and space group for [C6Trop]+[PF6]−, C14H27NOPF6, are reported [a = 16.1879(6) Å, b = 11.4271(2) Å, c = 10.3966(5) Å, α = 66.4949(3)°, β = 94.5589(0)°, γ = 93.3092(4)°, unit-cell volume V = 1923.17 Å3, Z = 1, and space group P1]. No detectable impurities were observed.
Ni3N was prepared by gaseous nitriding of nickel substrates using gas mixtures of high nitrogen activities, composed of NH3 and H2 at 1 atm and at temperatures between 175 °C and 550 °C. At least above 300 °C closed Ni3N layers developed, which possess distinct compressive macrostrain parallel to the surface. The observed hkl-anisotropy of the macrostrain could be ascribed to the elastic anisotropy as indicated by the single-crystal elastic constants of Ni3N obtained from first-principles calculations performed in this work. The macrostress originates from the thermal misfit between layer and substrate, developing upon cooling. The extent of macrostress is reduced by partial misfit accommodation by plastic deformation as well as by porosity.
We study the problem of flatness of two-input driftless control systems. Although a
characterization of flat systems of that class is known, the problems of describing all
flat outputs and of calculating them is open and we solve it in the paper. We show that
all x-flat outputs are parameterized by an arbitrary function of three
canonically defined variables. We also construct a system of 1st order PDE’s whose
solutions give all x-flat outputs of two-input driftless systems. We
illustrate our results by describing all x-flat outputs of models of a
nonholonomic car and the n-trailer system.
Solid oxide fuel cells produce electricity at very high efficiency and have very low to negligible emissions, making them an attractive option for power generation for electric utilities. However, conventional SOFC's are operated at 1000 °C or more in order to attain reasonable power density. The high operating temperature of SOFC's leads to complex materials problems which have been difficult to solve in a cost-effective manner. Accordingly, there is much interest in reducing the operating temperature of SOFC's while still maintaining the power densities achieved at high temperatures. There are several approaches to reduced temperature operation including alternative solid electrolytes having higher ionic conductivity than yttria stablilized zirconia, thin solid electrolyte membranes, and improved electrode materials. Given the proven reliability of zirconia-based electrolytes (YSZ) in long-term SOFC tests, the use of stabilized zirconia electrolytes in reduced temperature fuel cells is a logical choice. In order to avoid compromising power density at intermediate temperatures, the thickness of the YSZ electrolyte must be reduced from that in conventional cells (100 to 200 μm) to approximately 4 to 10 μm. There are a number of approaches for depositing thin ceramic films onto porous supports including chemical vapor deposition/electrochemical vapor deposition, sol-gel deposition, sputter deposition, etc. In this paper we describe an inexpensive approach involving the use of colloidal dispersions of polycrystalline electrolyte for depositing 4 to 10 μm electrolyte films onto porous electrode supports in a single deposition step. This technique leads to highly dense, conductive, electrolyte films which exhibit near theoretical open circuit voltages in H2/air fuel cells. These electrolyte films exhibit bulk ionic conductivity, and may see application in reduced temperature SOFC's, gas separation membranes, and fast response sensors.
To derive age- and sex-specific reference values for waist circumference (WC) and waist-to-height ratio (WHtR) for Han Chinese children and adolescents and to establish the prevalence of excess central adiposity in our study population.
Cross-sectional study of schoolchildren attending randomly selected primary and secondary schools in south-west China in October 2003 and April 2004. Anthropometry was measured using standard procedures. The LMS method was used to construct smoothed WC and WHtR percentile curves. Overweight and obesity were defined by the International Obesity Task Force (IOTF) criteria and the Working Group on Obesity in Children. Excess central adiposity fat was defined by previously published WC cut-points and a WHtR ≥ 0·5.
Primary and secondary schools in Chongqing, south-west China.
A total of 7326 (49·2 % boys) Han Chinese students at 5–17 years old.
On the basis of the IOTF criteria, 26·4 % of boys were overweight or obese compared with 16·4 % of girls (P < 0·001). WC cut-points identified 31 % of boys and 28 % of girls as having excess central adiposity, whereas using the WHtR criterion, 14·8 % of boys and 5·6 % of girls were identified. Young boys (5–12 years) had a significantly (P < 0·001) higher WHtR than girls.
We have constructed WC and WHtR percentile curves for Han Chinese children and adolescents living in Chongqing. Our measurements were based on a student population with a relatively high rate of overweight and obesity. These data will provide a point of reference for future studies measuring the prevalence of overweight and obesity in China.
Amorphous silica shells, used for functionalization of inorganic nanoparticles in bioapplications, were coated on chemically synthesized NaYF4:Yb,Er upconversion fluorescent nanoparticles via a reverse microemulsion method by using dual surfactants of polyoxyethylene (5) nonylphenylether and 1-hexanol, and tetraethyl orthosilicate as precursor. NaYF4:Yb,Er nanoparticles were equiaxed with a particle size of 11.1 ± 1.3 nm. The thickness of silica shell was ∼8 nm. NaYF4:Yb,Er/silica core/shell nanoparticles were well dispersed in solvents such as ethanol and deionized water. The emission intensities of NaYF4:Yb,Er/silica core/shell nanoparticles remained the same as that of uncoated nanoparticles after surface functionalization with an amine group using (3-aminopropyl)-trimethoxysilan. Silica, although providing a good barrier to the nonradiative relaxation between the upconversion nanoparticles and the environments, did not enhance the emission intensity of upconversion nanoparticles. To increase the emission intensity of NaYF4:Yb,Er/silica core/shell nanoparticles, an undoped NaYF4 shell (∼3-nm thick) was deposited on the upconversion nanoparticles before the silica coating. The total emission intensity of NaYF4:Yb,Er/NaYF4/silica core/shell/shell nanoparticles increased by 15 times compared to that without the intermediate NaYF4 shell. The critical shell thickness of NaYF4 was ∼3 nm, beyond which no further emission intensity enhancement was observed.