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We describe an ultra-wide-bandwidth, low-frequency receiver recently installed on the Parkes radio telescope. The receiver system provides continuous frequency coverage from 704 to 4032 MHz. For much of the band (
), the system temperature is approximately 22 K and the receiver system remains in a linear regime even in the presence of strong mobile phone transmissions. We discuss the scientific and technical aspects of the new receiver, including its astronomical objectives, as well as the feed, receiver, digitiser, and signal processor design. We describe the pipeline routines that form the archive-ready data products and how those data files can be accessed from the archives. The system performance is quantified, including the system noise and linearity, beam shape, antenna efficiency, polarisation calibration, and timing stability.
This article presents a brief review of our case studies of data-driven Integrated Computational Materials Engineering (ICME) for intelligently discovering advanced structural metal materials, including light-weight materials (Ti, Mg, and Al alloys), refractory high-entropy alloys, and superalloys. The basic bonding in terms of topology and electronic structures is recommended to be considered as the building blocks/units constructing the microstructures of advanced materials. It is highlighted that the bonding charge density could not only provide an atomic and electronic insight into the physical nature of chemical bond of materials but also reveal the fundamental strengthening/embrittlement mechanisms and the local phase transformations of planar defects, paving a path in accelerating the development of advanced metal materials via interfacial engineering. Perspectives on the knowledge-based modeling/simulations, machine-learning knowledge base, platform, and next-generation workforce for sustainable ecosystem of ICME are highlighted, thus to call for more duty on the developments of advanced structural metal materials and enhancement of research productivity and collaboration.
We consider a model with both a parametric global trend and a nonparametric local trend. This model may be of interest in a number of applications in economics, finance, ecology, and geology. We first propose two hypothesis tests to detect whether two nested special cases are appropriate. For the case where both null hypotheses are rejected, we propose an estimation method to capture certain aspects of the time trend. We establish consistency and some distribution theory in the presence of a large sample. Moreover, we examine the proposed hypothesis tests and estimation methods through both simulated and real data examples. Finally, we discuss some potential extensions and issues when modelling time effects.
A facile one-pot and environmentally friendly method was developed to synthesize multi-branched flowerlike gold (Au) nanostructures by reducing chlorate gold (HAuCl4) with hydrogen peroxide (H2O2) in the presence of sodium citrate. The multibranched Au nanostructures were characterized by transmission electron microscopy and Ultraviolet-visible (UV-vis) absorption spectroscopy. The molar ratio of sodium citrate to HAuCl4 and the concentrations of the reacted reagents play important roles in the formation of multibranched Au nanostructures. The multibranched Au nanostructures with sharp tips exhibit excellent surface-enhanced Raman scattering (SERS) ability of 4-aminothiophenol (PATP). The experimental and simulated results both confirm that the photoinduced catalytic coupling reaction of PATP transformation to 4,4′-dimercaptoazobenzene occurs on the surface of multibranched Au nanostructures at a high power during the SERS measurement. It is believed that these multibranched Au nanostructures may find potential applications in SERS, biosensors, and the photoinduced surface catalytic application fields.
The present study was undertaken to investigate the antiparasitic activity of extracellular products of Streptomyces albus. Bioactivity-guided isolation of chloroform extracts affording a compound showing potent activity. The structure of the compound was elucidated as salinomycin (SAL) by EI-MS, 1H NMR and 13C NMR. In vitro test showed that SAL has potent anti-parasitic efficacy against theronts of Ichthyophthirius multifiliis with 10 min, 1, 2, 3 and 4 h (effective concentration) EC50 (95% confidence intervals) of 2.12 (2.22–2.02), 1.93 (1.98–1.88), 1.42 (1.47–1.37), 1.35 (1.41–1.31) and 1.11 (1.21–1.01) mg L−1. In vitro antiparasitic assays revealed that SAL could be 100% effective against I. multifiliis encysted tomonts at a concentration of 8.0 mg L−1. In vivo test demonstrated that the number of I. multifiliis trophonts on Erythroculter ilishaeformis treated with SAL was markedly lower than that of control group at 10 days after exposed to theronts (P < 0.05). In the control group, 80% mortality was observed owing to heavy I. multifiliis infection at 10 days. On the other hand, only 30.0% mortality was recorded in the group treated with 8.0 mg L−1 SAL. The median lethal dose (LD50) of SAL for E. ilishaeformis was 32.9 mg L−1.
Invasive smooth cordgrass (Spartina alterniflora Loisel) eradication is important for the health of many coastal ecosystems. An integrated regime of continuous submergence after clear mowing, with three interval levels between mowing and submergence (5, 10, and 15 d) and three submergence depths (20, 30, and 50 cm), was implemented in cofferdams enclosing invader populations along a Chinese coast. In July of the following year, after the roots of mowed S. alterniflora had been submerged for 12 mo, some ramets grew under the regime with an interval of 15 d and the regime with a submergence depth of 20 cm, but no ramets occurred under the regimes with submergence depths of 30 or 50 cm and intervals of 5 or 10 d. Four crab species were documented: Helice tridens tientsinensis Rathbun, Sesarma dehaani H. Milne-Edwards, Ocypode stimpsoni Ortmann, and Chiromantes haematocheir de Haan. Biomass and abundance values of crab species in the cofferdams were similar to those in the mudflats but different from those in smooth cordgrass populations. Thus, the treatment of submergence after mowing, which was implemented in the cofferdams, can control S. alterniflora and provide a mudflat-like habitat that promotes crab recovery if this treatment uses the proper combination of submergence depth and interval between mowing and submergence.
We report on a target system supporting automated positioning of nano-targets with a precision resolution of
in three dimensions. It relies on a confocal distance sensor and a microscope. The system has been commissioned to position nanometer targets with 1 Hz repetition rate. Integrating our prototype into the table-top ATLAS 300 TW-laser system at the Laboratory for Extreme Photonics in Garching, we demonstrate the operation of a 0.5 Hz laser-driven proton source with a shot-to-shot variation of the maximum energy about 27% for a level of confidence of 0.95. The reason of laser shooting experiments operated at 0.5 Hz rather than 1 Hz is because the synchronization between the nano-foil target positioning system and the laser trigger needs to improve.
X-ray diffraction analysis, transmission electron microscopy, and thermodynamic calculation were used to investigate the effect of microstructural condition of austenite on the microstructural characteristics of the nanoscale bainite ferrite in a high carbon steel. As austenization temperature increases to 950 °C, there are a higher vacancy concentration and homogenized distribution level of the interstitial carbon atom in the austenite grains. The movement of more di-vacancies combination could encourage the generation of the γ → α embryo nucleus. The interstitial carbon atoms have a stronger inhibitory effect on the formation of the γ → α embryo nucleus and homogenized distribution of the interstitial carbon atoms are able to make the inhibitory effect exist everywhere in the austenite grains. In consequence, the bainite ferrite could only nucleate in a smaller area (several nanometers), and grow into slender laths in a smaller width and a larger length.
The 〈001〉-textured 36Pb(In1/2Nb1/2)O3–30Pb(Mg1/3Nb2/3)O3–34PbTiO3 (36PIN–30PMN–34PT) ceramics were successfully prepared by the templated grain growth method using BaTiO3 (BT) templates with an average edge length of 10 μm and a thickness of about 0.5 μm. The highest Lotgering factor of 95% has been achieved for the textured ceramics with 5 wt% BT templates sintered at 1240 °C. The Curie temperature (TC) and dielectric constant (εr) of the textured 36PIN–30PMN–34PT ceramics were 225 °C and 2850, respectively. The piezoelectric constant d33 of the textured samples was 780 pC/N and almost 2 times higher than that of random 36PIN–30PMN–34PT samples. The planar mode electromechanical coupling coefficient kp was 59% for the textured samples. Unipolar strain-field measurements for the textured ceramics exhibited 0.34% strain at 4 kV/mm.
Magnolia sinica, a Critically Endangered tree endemic to Yunnan, China, is one of the 20 plant species with extremely small populations approved by the Yunnan government for urgent rescue action before 2015. Information on the geographical distribution and population size of this species had not previously been reported, hindering effective conservation. We therefore carried out a survey of the literature and of herbarium specimens, followed by a detailed field survey and morphological measurements and observations of surviving individuals. We located 52 individuals in the wild, in eight localities. Two distinguishing morphological characters (tepal colour and tepal number) were revised based on observations of all remaining wild individuals that produced flowers and on one 30-year-old flowering plant in Kunming Botanical Garden. The survival rate of individuals propagated from seed for ex situ conservation at the Garden was 100% over 5 years; of 100 individuals transplanted to each of two reinforcement sites, 20 and 18, respectively, were alive after 6 years. We propose two groups of measures to protect M. sinica: (1) in situ conservation, population monitoring, and public engagement, and (2) ex situ conservation with reinforcement or reintroduction.
The genetic contribution of blood pressure and heart rate (HR) varied widely between studies. Demographic factors such as ethnicity, age and/or sex might explain some of the heterogeneity. We performed a systematic review focusing on four phenotypes: systolic blood pressure (SBP), diastolic blood pressure (DBP), HR and pulse pressure (PP). Meta-regression was conducted to analyze potential factors in relation to SBP and DBP heritability. A total of 10,613 independent twins that came from 17 studies were included in the analysis. The weighted mean value of heritability for SBP and DBP was 0.54 (95% CIs: 0.48–0.60) and 0.49 (95% CIs: 0.42–0.56). Comparatively, three studies of HR and four studies of PP heritability were limited for the heterogeneity test. Meta-regression showed that, on average, SBP heritability with additive genes/unique environment (AE) model tend to have a higher heritability than additive genes/shared environment/unique environment (ACE) model (coefficient = 0.0947, p = .0142). A similar result was found for DBP as well. No other factors such as sex, age, ethnicity, publication year were significantly associated with heritability variance. Our study shows heritability estimates based on twin studies of both SBP and DBP are around 50%, using an AE rather than an ACE model; the variance due to C ended up in A, suggesting that the AE model may overestimate heritability if a small contribution of shared environment exists.
Twins reared apart provide a fascinating experiment to distinguish genetic from environmental influences. However, there is as yet no broad report on distribution of twins reared apart, especially in the Chinese population. In this study, information on 18,295 volunteer twin pairs of all age groups was compiled in nine provinces or cities of China, and questionnaires were used for zygosity determination. It was discovered that twins reared apart from 0 to 10 years of age accounted for 2.2% of all twin interviewees, with the proportion of this 0–10 group separated before 1, 2, and 5 years old, accounting for 65.3%, 76.1%, and 91.3%, respectively. The proportion of twins reared apart is not significantly related to zygosity or gender, but it is related to region and twin age. As the age of twins lowers, the proportion of those reared apart gradually decreases. Twins reared apart will become rarer in the future and therefore should be cherished as a resource.
The aim of the present study was to investigate the prevalence of hyperhomocysteinaemia (HHCY; total plasma homocysteine (tHcy) concentration >15 μmol/l) and its major determinants in healthy Chinese northerners. A descriptive and cross-sectional study was conducted in Shaanxi Province, China. The study sample included 2645 participants (1042 men and 1603 women) aged >20 years. Demographic characteristics and lifestyle factors were assessed via questionnaire interviews and physical examination. Plasma levels of homocysteine and folate and methylenetetrahydrofolate reductase (MTHFR) gene polymorphism were determined according to standard methods. The prevalence of HHCY was 67·7 % (81·4 % in men and 58·8 % in women). The geometric mean of tHcy concentration was 19·1 μmol/l. The OR of HHCY were 0·44 (95 % CI 0·34, 0·57) for women v. men; 1·95 (95 % CI 1·41, 2·70), 1·41 (95 % CI 1·05, 1·88) and 0·76 (95 % CI 0·64, 0·89) for participants with smoking and alcohol drinking cessation and improved physical activity levels, respectively; 0·25 (95 % CI 0·17, 0·38), 0·33 (95 % CI 0·22, 0·49) and 0·56 (95 % CI 0·36, 0·88) for participants with an education level of elementary school, secondary school and university v. illiterate, respectively; 1·41 (95 % CI 1·13, 1·75) and 3·05 (95 % CI 2·35, 3·97) for participants with CT and TT v. CC genotype at MTHFR 677C → T polymorphism, respectively. These results demonstrate that the prevalence of HHCY is considerably high in Chinese northerners, especially in TT subjects, suggesting that implementation of tHcy-lowering strategies, such as lifestyle changes, is necessary.
We presented the investigation on the cooling rate dependent undercooling of the microsized and nanosized Bi droplets in the Zn matrix via differential fast scanning calorimetry at scanning rates ranging from 300 to 6000 K/s. The experimental results demonstrated that the embedded nanosized Bi droplets gave more reproducible undercooling measurements than that of microsized Bi droplets at the grain boundaries. In addition, different cooling rate dependences of undercooling of microsized and nanosized Bi droplets were found. When the cooling rate is increased from 300 to 6000 K/s, the undercooling of the embedded nanosized Bi droplets increased gradually from 125 to 130 K. However, for microsized Bi droplets at the grain boundaries, there was an obvious increase of undercooling when the cooling rate was higher than 2000 K/s. In other words, the undercooling evolution displayed a sigmoidal relationship with the increase in cooling rate, indicating the change of the heterogeneous nucleation mechanism from a surface-induced mode to a volume-induced one.
To assess correlations between cruciferous vegetable intake and urinary isothiocyanate (ITC) level, in addition to glutathione S-transferase (GST) genotypes and other individual factors.
The study included cohort participants whose urinary ITC levels had been previously ascertained. Urinary ITC was assessed using HPLC. Usual dietary intake of cruciferous vegetables was assessed using a validated FFQ and total dietary ITC intake was calculated. Recent cruciferous vegetable intake was determined. GST genotypes were assessed using duplex real-time quantitative PCR assays. Spearman correlations were calculated between the covariates and urinary ITC levels and linear regression analyses were used to calculate the mean urinary ITC excretion according to GST genotype.
Urban city in China.
The study included 3589 women and 1015 men from the Shanghai Women’s and Men’s Health Studies.
Median urinary ITC level was 1·61 nmol/mg creatinine. Self-reported usual cruciferous vegetable intake was weakly correlated with urinary ITC level (rs=0·1149; P<0·0001), while self-reported recent intake was more strongly correlated with urinary ITC (rs=0·2591; P<0·0001). Overall, the GST genotypes were not associated with urinary ITC level, but significant differences according to genotype were observed among current smokers and participants who provided an afternoon urine sample. Other factors, including previous gastrectomy or gastritis, were also related to urinary ITC level.
The study suggests that urinary secretion of ITC may provide additional information on cruciferous vegetable intake and that GST genotypes are related to urinary ITC level only in some subgroups.
A solution-processed method is developed to fabricate fully transparent resistive random access memory (RRAM) devices with a configuration of FTO/ZrO2/ITO, where the zirconium dioxide (ZrO2) layer was firstly deposited on fluorine tin oxide (FTO) substrate by sol-gel and then indium tin oxide (ITO) films were deposited on ZrO2 layer by sol-gel as the top electrodes.The solution processed FTO/ZrO2/ITO based RRAM devices show the fully transparency and excellent bipolar resistance switching behaviors. The resistance ratio between high and low resistance states was more than 10, and more than 100 switching cycles and good data retention and multilevel resistive switching have been demonstrated.
A bounded high order upwind scheme is presented for the modified Burgers’ equation by using the normalized-variable formulation in the finite volume framework. The characteristic line of the present scheme in the normalized-variable diagram is designed on the Hermite polynomial interpolation. In order to suppress unphysical oscillations, the present scheme respects both the TVD (total variational diminishing) constraint and CBC (convection boundedness criterion) condition. Numerical results demonstrate the present scheme possesses good robustness and high resolution for the modified Burgers’ equation.
The present study investigated the effects of xanthophyll supplementation on production performance, antioxidant capacity (measured by glutathione peroxidase, superoxide dismutase (SOD), catalase, total antioxidant capacity (T-AOC), and reduced glutathione:oxidised glutathione ratio (GSH:GSSG)) and lipid peroxidation (measured by malondialdehyde (MDA)) in breeding hens and chicks. In Expt 1, 432 hens were fed diets supplemented with 0 (control group), 20 or 40 mg xanthophyll/kg diet. Blood samples were taken at 7, 14, 21, 28 and 35 d of the trial. Liver and jejunal mucosa were sampled at 35 d. Both xanthophyll groups improved serum SOD at 21 and 28 d, serum T-AOC at 21 d and liver T-AOC, and serum GSH:GSSG at 21, 28 and 35 d and liver GSH:GSSG. Xanthophylls also decreased serum MDA at 21 d in hens. Expt 2 was a 2 × 2 factorial design. Male chicks hatched from 0 or 40 mg in ovo xanthophyll/kg diet of hens were fed a diet containing either 0 or 40 mg xanthophyll/kg diet. Liver samples were collected at 0, 7, 14 and 21 d after hatching. Blood samples were also collected at 21 d. In ovo-deposited xanthophylls increased antioxidant capacity and decreased MDA in the liver mainly within 1 week after hatching. Maternal effects gradually vanished during 1–2 weeks after hatching. Dietary xanthophylls increased antioxidant capacity and decreased MDA in the liver and serum mainly from 2 weeks onwards. Data suggested that xanthophyll supplementation enhanced antioxidant capacity and reduced lipid peroxidation in different tissues of hens and chicks.
The mouse sperm genome is resistant to in vitro heat treatment, and embryos derived from heated sperm can support full-term embryonic development, but the blastocyst rate and implantation rate are lower compared to embryos derived from fresh sperm. In the present study, the patterns of DNA methylation, histone H4K12 (ACH4K12) acetylation, H3K9 trimethylation (H3K9-TriM), and H3K27 trimethylation (H3K27-TriM) in preimplantation embryos derived from 65°C-heated sperm were investigated. Although no evident changes in global DNA methyaltion, histone H4K12 (ACH4K12) acetylation, and H3K9 trimethylation (H3K9-TriM) were found, significantly lower levels of H3K27-TriM, which was thought to be one of the reasons for low efficiency of mouse cloning, were found in the inner cell mass of heated-sperm derived blastocysts. Thus, defective modification of H3K27-TriM might contribute to compromised development of embryos derived from heated sperm.