To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
A novel low-profile two-arm backfire tapered cone helical antenna for telemetry tracking and command (TT&C) is introduced theoretically and experimentally in this paper. Compared with the conventional helical antenna, this design has a substantial decrease in its height and an increase both in its half power beamwidth (HPBW) and 3-dB axial ratio beamwidth by replacing the uniform structure with two tapered cone structures. It provides a maximum gain of 5.1 dBi, an excellent circular polarization radiation over a wide angular range of more than 124°, a 3-dB axial ratio bandwidth of 18.8%, a wide HPBW of more than 125°, and nearly equal E- and H- plane far-field patterns with high degree of axial symmetry over S-band (2–2.3 GHz). These excellent radiation characteristics with an endurable and compact structure make it an attractive candidate for TT&C application in microsatellite system, where the installation envelope and space for antenna are extremely limited.
Emerging functional imaging studies suggest that schizophrenia is associated with aberrant spatiotemporal interaction which may result in aberrant global and local dynamic properties.
We investigated the dynamic functional connectivity (FC) by using instantaneous phase method based on Hilbert transform to detect abnormal spatiotemporal interaction in schizophrenia. Based on resting-state functional magnetic resonance imaging, two independent datasets were included, with 114 subjects from COBRE [51 schizophrenia patients (SZ) and 63 healthy controls (HCs)] and 96 from OpenfMRI (36 SZ and 60 HCs). Phase differences and instantaneous coupling matrices were firstly calculated at all time points by extracting instantaneous parameters. Global [global synchrony and intertemporal closeness (ITC)] and local dynamic features [strength of FC (sFC) and variability of FC (vFC)] were compared between two groups. Support vector machine (SVM) was used to estimate the ability to discriminate two groups by using all aberrant features.
We found SZ had lower global synchrony and ITC than HCs on both datasets. Furthermore, SZ had a significant decrease in sFC but an increase in vFC, which were mainly located at prefrontal cortex, anterior cingulate cortex, temporal cortex and visual cortex or temporal cortex and hippocampus, forming significant dynamic subnetworks. SVM analysis revealed a high degree of balanced accuracy (85.75%) on the basis of all aberrant dynamic features.
SZ has worse overall spatiotemporal stability and extensive FC subnetwork lesions compared to HCs, which to some extent elucidates the pathophysiological mechanism of schizophrenia, providing insight into time-variation properties of patients with other mental illnesses.
Although higher dietary intake of MUFA has been shown to improve glycaemic control and lipid profiles, whether MUFA consumption from different sources is linked to the development of type 2 diabetes (T2D) remains unclear. We aimed to prospectively assess the associations of plant-derived MUFA (P-MUFA) and animal-derived MUFA (A-MUFA) intakes with T2D risk in a nationwide oriental cohort. Overall, 15 022 Chinese adults, aged ≥20 years, from the China Health and Nutrition Survey (CHNS 1997–2011) were prospectively followed up for a median of 14 years. Consumption of MUFA from plant and animal sources was assessed using 3-d 24-h recalls in each survey, and the cumulative average of intake was calculated. Multivariable-adjusted Cox models were constructed to estimate the hazard ratios (HR) of T2D according to quartiles of MUFA intake. P-MUFA were mainly consumed from cooked vegetable oils, fried bread sticks and rice, while A-MUFA were mainly consumed from pork, lard and eggs. Intake of P-MUFA was associated with a higher risk of T2D (HRQ4 v. Q1 1·50 (95 % CI 1·18, 1·90); Ptrend = 0·0013), whereas A-MUFA showed no significant association (HRQ4 v. Q1 0·84 (95 % CI 0·59, 1·20); Ptrend = 0·30). When further considering the cooking method of food sources, consumption of P-MUFA from fried foods was positively associated with T2D risk (HRQ4 v. Q1 1·60 (95 % CI 1·26, 2·02); Ptrend = 0·0006), whereas non-fried P-MUFA were not associated. Intake of MUFA from fried plant-based foods may elevate T2D risk among the Chinese population.
In an effort to improve the reliability of Arctic sea-ice predictions, an ensemble-based Arctic Ice Ocean Prediction System (ArcIOPS) has been developed to meet operational demands. The system is based on a regional Arctic configuration of the Massachusetts Institute of Technology general circulation model. A localized error subspace transform ensemble Kalman filter is used to assimilate the weekly merged CryoSat-2 and Soil Moisture and Ocean Salinity sea-ice thickness data together with the daily Advanced Microwave Scanning Radiometer 2 (AMSR2) sea-ice concentration data. The weather forecasts from the Global Forecast System of the National Centers for Environmental Prediction drive the sea ice–ocean coupled model. The ensemble mean sea-ice forecasts were used to facilitate the Chinese National Arctic Research Expedition in summer 2017. The forecasted sea-ice concentration is evaluated against AMSR2 and Special Sensor Microwave Imager/Sounder sea-ice concentration data. The forecasted sea-ice thickness is compared to the in-situ observations and the Pan-Arctic Ice-Ocean Modeling and Assimilation System. These comparisons show the promising potential of ArcIOPS for operational Arctic sea-ice forecasts. Nevertheless, the forecast bias in the Beaufort Sea calls for a delicate parameter calibration and a better design of the assimilation system.
In order to reveal the quantitative relationship between fatigue crack deflection path and cross-sectional grain boundary (GB) arrangement of metallic nanolayered composites (NLCs), a stochastic model was established based on the interface-dominant fatigue damage for the ultrafine-scale NLCs. The model indicates that the crack deflection length decreases with decreasing GB arrangement deviation and grain size of constituent layers. The observation and quantitative analysis of fatigue cracking behavior of the Cu/W multilayers with a layer thickness of 5 and 20 nm was conducted to verify the model.
Fatigue performance of metallic nanolayered composites (NLCs) has been gaining more and more attention due to the rapid development in the field of both micro-electro-mechanical systems and high-performance engineering structure materials and the increasing demand for long-term fatigue reliability. Metallic NLCs have exhibited different damage behaviors due to the effect of high-density heterogeneous interface compared with bulk materials and thin metal films. In this review paper, the cyclic deformation damage behavior, fatigue cracking feature, and fatigue properties of some metallic NLCs are reviewed. Effects of length scales, including layer thickness and grain size, on fatigue damage behaviors of the NLCs are revealed, and the transition of the fatigue cracking behavior and the corresponding damage mechanism are discussed. Then, the fatigue properties of some typical metallic NLCs are presented and compared with that of bulk materials and metal thin films. The effect of interface type and grain boundary alignment is also discussed to correlate with fatigue cracking resistance of the NLCs. Finally, some prospective research topics on fatigue performance of metallic NLCs are addressed.
In this paper, the recent studies of laboratory astrophysics with strong magnetic fields in China have been reviewed. On the Shenguang-II laser facility of the National Laboratory on High-Power Lasers and Physics, a laser-driven strong magnetic field up to 200 T has been achieved. The experiment was performed to model the interaction of solar wind with dayside magnetosphere. Also the low beta plasma magnetic reconnection (MR) has been studied. Theoretically, the model has been developed to deal with the atomic structures and processes in strong magnetic field. Also the study of shock wave generation in the magnetized counter-streaming plasmas is introduced.
Postnatal rapid growth by excess intake of nutrients has been associated with an increased susceptibility to diseases in neonates with intra-uterine growth restricted (IUGR). The aim of the present study was to determine whether postnatal nutritional restriction could improve intestinal development and immune function of neonates with IUGR using piglets as model. A total of twelve pairs of normal-birth weight (NBW) and IUGR piglets (7 d old) were randomly assigned to receive adequate nutrient intake or restricted nutrient intake (RNI) by artificially liquid feeding for a period of 21 d. Blood samples and intestinal tissues were collected at necropsy and were analysed for morphology, digestive enzyme activities, immune cells and expression of innate immunity-related genes. The results indicated that both IUGR and postnatal nutritional restriction delayed the growth rate during the sucking period. Irrespective of nutrient intake, piglets with IUGR had a significantly lower villous height and crypt depth in the ileum than the NBW piglets. Moreover, IUGR decreased alkaline phosphatase activity while enhanced lactase activity in the jejunum and mRNA expressions of Toll-like receptor 9 (TLR-9) and DNA methyltransferase 1 (DNMT1) in the ileum of piglets. Irrespective of body weight, RNI significantly decreased the number and/or percentage of peripheral leucocytes, lymphocytes and monocytes of piglets, whereas the percentage of neutrophils and the ratio of CD4+ to CD8+ were increased. Furthermore, RNI markedly enhanced the mRNA expression of TLR-9 and DNMT1, but decreased the expression of NOD2 and TRAF-6 in the ileum of piglets. In summary, postnatal nutritional restriction led to abnormal cellular and innate immune response, as well as delayed the growth and intestinal development of IUGR piglets.
Epidemiological studies have examined associations between dietary patterns and the risk of type 2 diabetes. However, information on dietary patterns and the risk of type 2 diabetes in Chinese populations is scarce. The aim of the present study was to identify dietary patterns and examine their association with incident hyperglycaemia in Nanjing, China.
A community-based prospective cohort study. Dietary assessment was carried out using a validated eighty-seven-item FFQ. Dietary patterns were identified by exploratory factor analysis. Participants were categorized into tertiles of dietary factor score for each dietary pattern. The relationship between dietary patterns and hyperglycaemia risk was analysed using multivariable linear and Cox regression.
Seven communities from two urban districts in Nanjing, China.
A total of 2900 of Chinese local residents aged 30 years or above, free of hyperglycaemia and other serious diseases, who participated in the baseline survey from June to September 2007 were followed up 3 years later from June to September 2010 for the development of hyperglycaemia. Fasting blood samples were collected at both baseline and 3-year follow-up surveys. Hyperglycaemia was defined as fasting plasma glucose concentration of ≥6·1 mmol/l or already taking oral hyperglycaemia agents for treatment of type 2 diabetes.
Five major dietary patterns were identified: (i) the ‘condiments’ pattern; (ii) the ‘animal and plant protein’ pattern; (iii) the ‘healthy traditional’ pattern; (iv) the ‘fruits, eggs and juice’ pattern; and (v) the ‘alcohol, milk and tea’ pattern. A total of 2093 (72·2 %) individuals completed the follow-up survey and the 3-year cumulative incidence of hyperglycaemia was 7·5 % (158/2093). A 1-unit increase in the score for the ‘healthy traditional’ pattern was associated with a decrease of 0·054 mmol/l in fasting plasma glucose (P=0·017), while a 1-unit increase in the ‘fruits, eggs and juice’ pattern score was associated with an increase of 0·050 mmol/l in fasting plasma glucose (P=0·023) by multivariable linear regression. For men, tertile 3 of the ‘fruits, eggs and juice’ pattern was associated with an 88 % greater risk (hazard ratio=1·88; 95 % CI 1·04, 3·54) of hyperglycaemia than tertile 1 of this pattern. Being in tertile 3 of the ‘alcohol, milk and tea’ pattern was associated with a 35 % greater risk (hazard ratio=1·35; 95 % CI 1·04, 2·16) relative to tertile 1 in women, while for the ‘'healthy traditional’ pattern tertile 3 was associated with a 41 % lower risk (hazard ratio=0·59; 95 % CI 0·35, 0·99) compared with tertile 1. The ‘condiments’ and the ‘animal and plant protein’ patterns were not independently associated with hyperglycaemia.
Our findings suggest that modifying dietary patterns could reduce hyperglycaemia incidence in the mainland Chinese adult population.
Considerable controversy exists regarding the associations of dietary patterns with the risk of all-cause, CVD and stroke mortality. Therefore, a meta-analysis was conducted to elucidate the potential associations between dietary patterns and the risk of all-cause, CVD and stroke mortality. The PubMed database was searched for prospective cohort studies on the associations between dietary patterns and the risk of all-cause, CVD and stroke mortality published until February 2014. Random-effects models were used to calculate the summary relative risk estimates (SRRE) based on the highest v. the lowest category of dietary pattern scores. Stratified analyses were conducted based on sex, geographical region, follow-up duration, and adjustment/non-adjustment for energy intake. A total of thirteen prospective cohort studies involving 338 787 participants were included in the meta-analysis. There was evidence of inverse associations between the prudent/healthy dietary pattern and the risk of all-cause (SRRE = 0·76, 95 % CI 0·68, 0·86) and CVD (SRRE = 0·81, 95 % CI 0·75, 0·87) mortality and an absence of association between this dietary pattern and stroke mortality (SRRE = 0·89, 95 % CI 0·77, 1·02). However, no significant associations were observed between the Western/unhealthy dietary pattern and the risk of all-cause (SRRE = 1·07, 95 % CI 0·96, 1·20), CVD (SRRE = 0·99, 95 % CI 0·91, 1·08) and stroke (SRRE = 0·94, 95 % CI 0·81, 1·10) mortality. In conclusion, the findings provide evidence that greater adherence to a prudent/healthy dietary pattern is associated with a lower risk of all-cause and CVD mortality and not significantly associated with stroke mortality and that the Western/unhealthy dietary pattern is not associated with all-cause, CVD and stroke mortality. Further studies are required to confirm these findings.
Background: Several studies have investigated the association of FKBP5 gene polymorphisms with mood disorders, but findings are not always consistent. The aim of our study was to assess the association of FKBP5 gene polymorphisms with mood disorders using a meta-analysis.
Methods: Data were collected from the following electronic databases: PubMed, Elsevier Science Direct, Cochrane Library, Chinese Biomedical Literature Database, China National Knowledge Infrastructure and Wanfang, with the last report up to March 2010. Meta-analysis was performed in a fixed/random effect model.
Results: We identified six studies using search, and one study was excluded because of unavailable data. One study contained data on two different ethnicities and we treated them independently. Thus, six separate studies (2655 cases and 3593 controls) were included in the meta-analysis. Meta-analysis was performed for three FKBP5 gene polymorphisms (rs1360780, rs3800373 and rs4713916) in overall and Caucasian populations. We did not detect any association of FKBP5 gene rs1360780 and rs3800373 polymorphisms with mood disorders (p > 0.05). However, a significant association of FKBP5 gene rs4713916 polymorphism with mood disorders was found, and the heterozygous individual (GA genotype) was more susceptible to mood disorders in comparison to homozygous analogues (GG or AA genotype) [overall: GA vs. GG: OR (odds ratio) = 1.20, 95% CI (confidence interval) = 1.03–1.40, p = 0.02; GA vs. AA: OR = 1.44, 95% CI = 1.09–1.90, p = 0.009; Caucasian: GA vs. GG: OR = 1.22, 95% CI = 1.04–1.44, p = 0.01; GA vs. AA: OR = 1.43, 95% CI = 1.09–1.89, p = 0.01].
Conclusion: This meta-analysis shows that mood disorders are associated with FKBP5 gene rs4713916 polymorphism, but not with rs1360780 and rs3800373.
Great research efforts to investigate the glass-forming ability (GFA) in alloys have been made, leading to an observation that a pinpoint composition produces the best glass-forming characteristics. The reason for this observation is still unknown, limiting the development of bulk metallic glasses (MGs) with a relatively large size. In this work, systematic experimental measurements coupled with calculations were performed to address this issue using the NiNb binary alloy system. It is found that the atomic-level packing efficiency and the clusters-level regularity parameters strongly contribute to their GFA. In particular, the best glass former found in a pinpoint composition possesses the local maximum of the atomic-packing efficiency and the highest degree of the cluster regularity. This work provides an understanding of GFA from atomic and cluster levels and will shed light on the development of more MGs with relatively large critical casting sizes.
Compound effects of B and Y additions on the microstructures and properties of a new type of high-strength and high-conductivity (HSHC) Cu–Mg–Te alloys are investigated on the aspects of purification and precipitation. Because of the purification function of B and Y additions, the tensile strength increased superlatively by the amplitude of 21.7% with a similar increase of elongation and the electrical conductivity of 4.2%. By comparison of the calculated decomposition pressures of B2O3 and Y2O3 at different temperatures, it can be concluded that the boron oxide is more stable than the yttrium oxide in the copper liquid, indicating the superior deoxygenization purification of the rare earth yttrium. The dispersive distribution of the Y–B compounds (YB6) was another factor for the improvement of the mechanical properties of the copper alloy. Finally, the copper alloy treated by hot rolling, cold rolling, and annealing processes in sequence exhibits HSHC with the tensile strength of 610.7 MPa and the electrical conductivity of 53.1%IACS.
Intra-uterine growth-retarded (IUGR) neonates have shown an impairment of postnatal intestinal development and function. We hypothesised that the immune function of IUGR neonates might be affected by increased nutrient intake (NI) during the suckling period. Therefore, we investigated the effects of high NI (HNI) on the growth performance, intestinal morphology and immunological response of IUGR and normal-birth weight (NBW) piglets. A total of twelve pairs of IUGR and NBW piglets (7 d old) were randomly assigned to two different nutrient-level formula milk groups. After 21 d of rearing, growth performance, the composition of peripheral leucocytes, serum cytokines and intestinal innate immune-related genes involved in the Toll-like receptor (TLR)-4–myeloid differentiation factor 88–NF-κB pathway were determined. The results indicated that IUGR decreased the average daily DM intake (ADMI) and the average daily growth (ADG). However, the ADMI and ADG were increased by HNI, irrespective of body weight. Likewise, serum cytokines (TNF-α and IL-1β) and ileal gene expressions (TLR-4, TLR-9, TRAF-6 and IL-1β) were lower in IUGR piglets, whereas HNI significantly increased blood lymphocyte percentage and serum IL-10 concentrations, but decreased neutrophil percentage, serum IL-1β concentrations and ileal gene expressions (NF-κB and IL-1β). Furthermore, IUGR piglets with HNI exhibited lower serum concentrations of TNF-α and IL-1β than NBW piglets, and these alterations in the immune traits of IUGR piglets receiving HNI were accompanied by decreasing ileal gene expressions of TLR-4, TLR-9, NF-κB and IL-1β that are related to innate immunity. In conclusion, the present findings suggest that increased NI during the suckling period impaired the immune function of neonatal piglets with IUGR.
A 2-2-type nanostructure bilayer film of CoFe2O4/Pb(Zr0.52Ti0.48)O3 was successfully prepared on the (111)Pt/Ti/SiO2/Si substrate. The Pb(Zr0.52Ti0.48)O3 layer in the bilayer film is (111) oriented and is a mixture of tetragonal and monoclinic phases. The results from an in situ X-ray diffraction analysis of the multiferroic bilayer film under statistic magnetic field indicate that the monoclinic-tetragonal phase transition was induced by magnetostriction of the CoFe2O4 layer. A large magnetoelectric effect was obtained probably because of the different polarization directions of the tetragonal and monoclinic phases.
Molecular dynamic simulations of helium atoms escaping from a helium-filled nanobubble near the surface of crystalline palladium reveal unexpected behavior. Significant deformation and cracking near the helium bubble occur initially, and then a channel forms between the bubble and the surface, providing a pathway for helium atoms to propagate toward the surface. The helium atoms erupt from the bubble in an instantaneous and volcano-like process, which leads to surface deformation consisting of cavity formation on the surface, along with modification and atomic rearrangement at the periphery of the cavity. The present simulation results show that, near the palladium surface, there is a helium-bubble-free zone, or denuded zone, with a typical thickness of about 3.0 nm. Combined with experimental measurements and continuum-scale evolutionary model predictions, the present atomic simulations demonstrate that the thickness of the denuded zone, which contains a low concentration of helium atoms, is somewhat larger than the diameter of the helium bubbles in the metal tritide. Furthermore, a relationship between the tensile strength and thickness of metal film is also determined.
CdS nanocrystals embedded in sodium borosilicate glass were synthesized through sol-gel process. The CdS nanocrystals were usually 10 to 20 nm in size. The microstructure of CdS nanocrystals was determined to be of the hexagonal phase. The morphology and microstructure of the glass were examined using diverse techniques including scanning-probe microscopy (SPM), x-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM), energy dispersion x-ray spectra (EDAX), and high-resolution TEM (HRTEM). The linear optical absorption spectrum of the glass showed a blue shift as a result of quantum-size effect. Furthermore, the third-order optical nonlinearities of the glass were studied by Z-scan technique at a wavelength of 770 nm. The results showed that the third-order optical nonlinear refractive index γ, absorption coefficient β, and susceptibility χ(3) were determined to be −2.16 × 10−16 m2/W, 6.32 × 10−11 m/W, and 1.20 × 10−10 esu, respectively, which were greater than those reported previously for CdS nanocrystals embedded in different matrices.
In this paper, we consider the asymptotic behaviour for the non-local parabolic problem
with a homogeneous Dirichlet boundary condition, where λ > 0, p > 0 and f is non-increasing. It is found that (a) for 0 < p ≤ 1, u(x, t) is globally bounded and the unique stationary solution is globally asymptotically stable for any λ > 0; (b) for 1 < p < 2, u(x, t) is globally bounded for any λ > 0; (c) for p = 2, if 0 < λ < 2|∂Ω|2, then u(x, t) is globally bounded; if λ = 2|∂Ω|2, there is no stationary solution and u(x, t) is a global solution and u(x, t) → ∞ as t → ∞ for all x ∈ Ω; if λ > 2|∂Ω|2, there is no stationary solution and u(x, t) blows up in finite time for all x ∈ Ω; (d) for p > 2, there exists a λ* > 0 such that for λ > λ*, or for 0 < λ ≤ λ* and u0(x) sufficiently large, u(x, t) blows up in finite time. Moreover, some formal asymptotic estimates for the behaviour of u(x, t) as it blows up are obtained for p ≥ 2.
The genetic variation of isozymes [esterase (EST), superoxide dismutase (SOD), malate dehydrogenase (MDH), malic enzyme (ME) and glucose-6-phosphate dehydrogenase (G6PD)] extracted from two different adult tissues (adductor muscle and gill) of Pteria penguin R. and offspring from two stocks of Pinctada martensii D. were analysed by vertical polyacrylamide gel electrophoresis. The result showed an obvious and stable variation in the isozyme phenotypes in two different pearl oyster species. The SOD and EST isozymes from gill and MDH, ME and G6PDH from adductor muscle were species-specific. The electrophoretograms of these isozymes could be used as markers to differentiate the two pearl oysters. Between inbreeding and hybridized stocks of P. martensii, the electrophoresis patterns of isozymes were alike, but the similarities of electrophoretograms in the inbreeding progenies were higher than in the hybridized ones. The characteristic electrophoretograms of isozymes could be applied as molecular markers in the breeding of pearl oysters.