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The dipeptide DL-methionyl-DL-Methionine (Met-Met) has extremely low water solubility and better absorption than other methionine sources (such as DL-methionine and L-methionine) available in the market. Therefore, six diets (D1, D2, D3, D4, D5 and D6) containing 0 %, 0.07%, 0.15%, 0.21%, 0.28% and 0.38% Met-Met were formulated to investigate the effects of Met-Met on Oreochromis niloticus. The results indicated that percent weight gain and specific growth rate of fish fed with D2 and D3 diets were higher than those fed with D1, D4-D6 diets. The levels of total essential amino acid in whole body of fish fed with D3 and D4 diets were significantly higher than those fed the D1 diet. Superoxide dismutase activity and malondialdehyde content were no significant difference in fed the diet with or without Met-Met supplementation. Majority of reads derived from the fish intestines belonged to members of Fusobacteria, followed by Bacteroidetes, Proteobacteria. Diversity of intestinal microbiota and total antioxidant capacity in fish fed with D3 diet was significantly higher than that of other groups. Since due to the growth results the authors conclude the optimal proportion of Met was 0.61%, and the addition of Met-Met was 0.15% in O. niloticus.
Considering the nonlocal small-scale effect and surface effect, we perform the size-dependent vibration analysis of carbon nanotube (CNT). The modified governing equations for CNT’s vibration behaviors are derived by using the nonlocal Euler–Bernoulli and Timoshenko beam models, together with the consideration of surface tension and surface elasticity. According to the numerical experiments, both small-scale effect and surface effect make a substantial difference. For flexural vibration, size effect for CNT’s vibration behaviors weakens with the increase of its diameter, but strengthens with the increase of the length–diameter ratio; for shear vibration with constant length–diameter ratio, a nonlinear correlation between size effect and CNT’s diameter exists, suggesting that there is a typical diameter for CNTs, which corresponds to the “strongest” size effect. In addition, the effects of elastic substrate modulus, temperature change, and axial preloading on the vibration behaviors and their size-dependence are analyzed, respectively.
In this paper, we review the status of the multifunctional experimental platform at the National Laboratory of High Power Laser and Physics (NLHPLP). The platform, including the SG-II laser facility, SG-II 9th beam, SG-II upgrade (SG-II UP) facility, and SG-II 5 PW facility, is operational and available for interested scientists studying inertial confinement fusion (ICF) and a broad range of high-energy-density physics. These facilities can provide important experimental capabilities by combining different pulse widths of nanosecond, picosecond, and femtosecond scales. In addition, the SG-II UP facility, consisting of a single petawatt system and an eight-beam nanosecond system, is introduced including several laser technologies that have been developed to ensure the performance of the facility. Recent developments of the SG-II 5 PW facility are also presented.
Suboptimal vitamin B2 status is encountered globally. Riboflavin deficiency depresses growth and results in a fatty liver. The underlying mechanisms remain to be established and an overview of molecular alterations is lacking. We investigated hepatic proteome changes induced by riboflavin deficiency to explain its effects on growth and hepatic lipid metabolism. In all, 360 1-d-old Pekin ducks were divided into three groups of 120 birds each, with twelve replicates and ten birds per replicate. For 21 d, the ducks were fed ad libitum a control diet (CAL), a riboflavin-deficient diet (RD) or were pair-fed with the control diet to the mean daily intake of the RD group (CPF). When comparing RD with CAL and CPF, growth depression, liver enlargement, liver lipid accumulation and enhanced liver SFA (C6 : 0, C12 : 0, C16 : 0, C18 : 0) were observed. In RD, thirty-two proteins were enhanced and thirty-one diminished (>1·5-fold) compared with CAL and CPF. Selected proteins were confirmed by Western blotting. The diminished proteins are mainly involved in fatty acid β-oxidation and the mitochondrial electron transport chain (ETC), whereas the enhanced proteins are mainly involved in TAG and cholesterol biosynthesis. RD causes liver lipid accumulation and growth depression probably by impairing fatty acid β-oxidation and ETC. These findings contribute to our understanding of the mechanisms of liver lipid metabolic disorders due to RD.
The present research focuses on glacier changes in the southeast of the Qinghai–Xizang (Tibetan) Plateau, where most of the temperate glaciers in China are located. Our results show that the 102 measured glaciers in the region have all retreated between 1915 and 1980, with total area and volume decreases of 47.9 km2 and 6.95 km3, respectively. The extrapolated mass loss of all glaciers in the Gangrigabu mountains amounted to 27 km3, 9.8% of the ice mass in 1915. Between 1980 and 2001, glaciers in the region have also experienced a general retreat; however, up to 40% of the glaciers were advancing. Our analysis demonstrates that precipitation in the studied area has increased substantially since the mid-1980s. This precipitation increase is likely to bring about a positive mass balance for glaciers in the region, so that the retreat of retreating glaciers might slow down or even turn into advance. Considering the sensitivity of the temperate glaciers in the region and the uncertainty in climate projections, more attention must be paid to glacier changes in the southeast Tibetan Plateau region.
The Tarim river basin, a river system formed by the convergence of nine tributaries, is the most heavily glacierized watershed in arid northwest China. In the basin, there are 11 665 glaciers with a total area of 19 878 km2 and a volume of 2313 km3. Glaciers in the basin play a significant role in the water resource system. It is estimated that they provide about 133 x 108 m3 of meltwater annually, contributing 39% of the total river runoff. Under the influence of global warming, northwest China has experienced a generally warmer and drier climate since the mid-19th century. However, a so-called ‘warm and wet transition’ has occurred since the late 1980s, evidenced by an increase in both precipitation and stream discharge in the Xinjiang Autonomous Region and neighboring regions. This paper describes how glaciers in the Tarim river basin have responded to such warming and increased precipitation, and the impact of these glacier changes. We analyzed the variations of more than 3000 glaciers since the 1960s using topographical maps, high-resolution satellite images and aerial photographs of the river basin. Our results indicate that glaciers in the basin have been mostly in retreat in the past 40 years, and ice wastage has significantly influenced water resources in the Tarim river basin. Estimation by a degree-day meltwater model shows the positive anomaly in stream runoff of the Tailan river can be partly attributed to the increase in glacier runoff (amounting to one-third of the stream discharge), and a rough estimation using observed average ablation on the termini of 15 glaciers in China verifies that the mass loss calculated by a glacier area-volume relation is reasonable.
This work designed a facile preparation for an SiO2/C composite as the anode material for lithium ion battery. Both SiO2 and carbon are amorphous. SiO2 and carbon are mixed uniformly. The SiO2/C composite shows high specific capacity, cycle stability, and rate capability in lithium ion battery charge–discharge test. A stable reversible capacity of 1024 mA h/g at the current density of 100 mA/g is reached. The capacity retains 83% after 100 cycles. The uniform mixture of SiO2 and carbon leads to reduced volume change during the lithiation and delithiation of SiO2, together with the amorphous nature of SiO2 explains the high cycling stability. The carbon coating is a key factor for the high capacity and stability due to the increased electrical conductivity and reduced volume change. The resistance of the solid electrolyte interface film and charge transfer resistance of the SiO2/C composite are much smaller than those of pure carbon, which is a direct proof of the improved conductivity of the material by the carbon coating.
Tungstate based phosphors have efficient absorption in the UV region and can be used for UV-pumped light emitting. For novel and effective materials and synthesis methods in this system, a series of Eu3+ and Tb3+ co-doped NaY(WO4)2 phosphors have been synthesized via the molten salt method. The powder X-ray diffraction (PXRD) patterns, scanning electronic microscope (SEM), and photoluminescent spectra have been characterized for the prepared samples. The results show the flux (NaCl) not only decreases the reaction temperature (700–900 °C) than the normal solid state synthesis (∼1000 °C), but also controls the morphology of the products. The shape and size of products can be changed simply and effectively by the reaction conditions, such as temperature and heating time. It is also found that the emission colors of the samples can be tuned from red to green by simply adjusting the doping concentrations of Eu3+ and Tb3+ ions under the same wave length excitation, which has potential applications for multi-color display and illumination as a single-component phosphor.
In this work, we investigate electromagnetohydrodynamic (EMHD) flow of Powell-Eyring fluid through a slit confinement. The approximate analytical solution and numerical result of EMHD velocity are obtained by using homotopy perturbation method and Chebyshev spectral method, respectively. The analytical solutions are found to be in good agreement with numerical results under the same conditions. The influences of Hartmann number Ha, electrical field strength parameter S, the Powell-Eyring fluid parameters γ and β on velocity are discussed in detail. It is found that the volume flow rate of Newtonian fluid is always larger than that of Powell-Eyring fluid. The results reveal the intricate interaction between EMHD effect and fluid rheology involving non-Newtonian fluid. Therefore, the results are useful in dealing with some non-Newtonian biomicrofluidic systems.
be the infinite expansion of a continued fraction for an irrational number
, and let
) be the number of distinct partial quotients, each of which appears at least once (respectively, exactly
times, at least
times) in the sequence
. In this paper, it is proved that, for Lebesgue almost all
Ca0.98Eu0.02Al1−4δ/3Si1+δN3 (δ = 0–0.36) red-emitting phosphors were prepared by carbothermal reduction and nitridation method with stable and inexpensive CaCO3 as Ca source. Optimal nominal composition was obtained at δ = 0.18, showing intense emission peaked at 625 nm and high external quantum efficiency of 71%. The emission wave length could be successfully tuned from 630 to 606 nm with increasing δ value. Ca0.98Eu0.02Al1−4δ/3Si1+δN3 phosphors provided two coordinated environments for Eu2+ ions, resulting in two fitted Gaussian peaks. Energy transfer from Eu2+ sites in Si-rich environments to those in Si/Al-equivalent modes has been confirmed by analysis of the decay curve of each peak. The decay behaviors suggested that energy transfer effect slowed with higher δ value. Finally, warm white light was created by combining as-prepared red-emitting Ca0.98Eu0.02Al0.76Si1.18N3 and yellow-emitting YAG:Ce3+ phosphors with a blue-emitting chip, exhibiting a color rendering index Ra of 91 at a low correlated color temperature of 3500 K with a luminous efficiency of 79 lm/W.
To examine the vitamin D status, SNP of the vitamin D receptor gene (VDR) and the effects of vitamin D supplementation on parathyroid hormone and insulin secretion in adult males with obesity or normal weight in a subtropical Chinese city.
An intervention trial.
Shenzhen City, Guangdong Province, China.
From a cross-sectional survey conducted from June to July, eighty-two normal-weight and ninety-nine obese males (18–69 years) were screened to analyse their vitamin D status and for five SNP of VDR. From these individuals, in the same season of a different year, obese and normal-weight male volunteers (twenty-one per group) were included for an intervention trial with oral vitamin D supplementation at 1250 µg/week for 8 weeks.
For the survey, there was no significant difference (P>0·05) in baseline circulating 25-hydroxyvitamin D concentrations or in the percentages of participants in different categories of vitamin D status between the two groups. The VDR SNP, rs3782905, was significantly associated with obesity (P=0·043), but none of the examined SNP were correlated with serum 25-hydroxyvitamin D when adjusted for age, BMI and study group. After vitamin D supplementation, serum 25-hydroxyvitamin D concentration, hypersecretions of parathyroid hormone and insulin, and insulin resistance in the obese were changed beneficially (P<0·05); however, the increase in serum 25-hydroxyvitamin D was less than that of the normal-weight men.
For obese and normal-weight men of subtropical China, the summer baseline vitamin D status was similar. However, oral vitamin D supplementation revealed a decreased bioavailability of vitamin D in obese men and ameliorated their hypersecretion of parathyroid hormone and insulin resistance.
Clownfish and their associated sea anemones are icons of tropical and
subtropical coastal ecosystems, but bleaching and collecting for the
aquarium trade has reduced their population densities in several
Indo-Pacific locations. We surveyed four Entacmaea
quadricolor populations and their associated clownfish
Amphiprion clarkii in Hong Kong. These assemblages
represented a combination of exposed and sheltered, flat bottomed and sloped
conditions. Different from tropical areas, where E.
quadricolor is usually found in sheltered shallow waters, the
four populations in Hong Kong were distributed in 4–10 m depths, being
densest on a 40 × 80 m slope of volcanic rocks (34.2–76.6% substrate cover
and 48.7–102.1 ind m−2) at an exposed site. This distribution
pattern could be explained by the high turbidities associated with river
discharge and sedimentation rates in local waters, which discourage the
establishment of E. quadricolor populations in sheltered bays; shallow
habitats might not be suitable for E. quadricolor in Hong
Kong due to strong wave actions generated by typhoons. Amphiprion
clarkii was present at low densities
(0.07–0.26 fish m−2) across the sites. Our data provide a
baseline for monitoring the changes of these conspicuous members of shallow
water communities in Hong Kong.
The fabrication of Ce3+-doped lutetium oxyorthosilicate (Lu2SiO5:Ce, LSO:Ce) scintillation ceramics was investigated by pressureless sintering starting from synthetic submicrometer polycrystalline LSO:Ce powder. It was found that translucent LSO ceramics were densified successfully with relative density of 99.5% under sintering condition of 1720 °C for 4 h. As-sintered LSO ceramics were pore-free with average grain size of 5 μm and exhibited a translucent state. The broad emission spectra centered at 419 nm of the LSO:Ce ceramics under vacuum ultraviolet (VUV) and UV excitation at room temperature. Under x-ray excitation, the overall emission intensity of obtained LSO ceramics achieved twice of that of bismuth germanium oxide (also known as bismuth germanate) single crystal at room temperature. Under excitation of 356 nm and emission of 420 nm, the luminescence decay time of the obtained LSO scintillation ceramics reached only 21.2 ns. The light yield of the LSO ceramics was 21,300 ph/MeV, which reached 91% of that of LSO single crystal.
Polymorphisms of genes participating in iron transportation have been associated with Alzheimer's disease (AD) risk. The association between transferrin (TF) gene rs1049296 (P570S) polymorphism and AD is controversial.
We performed meta analysis on data from 19 studies with 6310 cases and 13661 controls to reexamine the association between the TF gene rs1049296 polymorphism and AD. We applied a fixed-effects model to combine the odds ratio (OR) and 95% confidence intervals (95% CI). Egger's test was carried out to evaluate the potential publication bias.
The overall ORs with 95% CIs showed statistical association between the TF gene rs1049296 polymorphism and the risk of AD in the allele contrast, the recessive model and the dominant model for allele C2 (fixed-effects pooled OR 1.11; 95% CI 1.05 to 1.17, pooled OR 1.13; 95% CI 1.06 to 1.21, and pooled OR 1.23; 95% CI 1.03 to 1.47, respectively). In the contrast of C2C2+C2C1 vs C1C1, large heterogeneity among the Asian subgroup (p=0.041, I2= 68.6%) was observed but not among the overall population (p = 0.184, I2= 22.4%). No publication bias was observed.
The present meta analysis demonstrated that TF gene rs1049296 polymorphism is a genetic determinant of AD.
In cancer research, high-throughput profiling studies have been extensively conducted, searching for markers associated with prognosis. Owing to the ‘large d, small n’ characteristic, results generated from the analysis of a single dataset can be unsatisfactory. Recent studies have shown that integrative analysis, which simultaneously analyses multiple datasets, can be more effective than single-dataset analysis and classic meta-analysis. In most of existing integrative analysis, the homogeneity model has been assumed, which postulates that different datasets share the same set of markers. Several approaches have been designed to reinforce this assumption. In practice, different datasets may differ in terms of patient selection criteria, profiling techniques, and many other aspects. Such differences may make the homogeneity model too restricted. In this study, we assume the heterogeneity model, under which different datasets are allowed to have different sets of markers. With multiple cancer prognosis datasets, we adopt the accelerated failure time model to describe survival. This model may have the lowest computational cost among popular semiparametric survival models. For marker selection, we adopt a sparse group minimax concave penalty approach. This approach has an intuitive formulation and can be computed using an effective group coordinate descent algorithm. Simulation study shows that it outperforms the existing approaches under both the homogeneity and heterogeneity models. Data analysis further demonstrates the merit of heterogeneity model and proposed approach.
Function is an ambiguous concept, whereas having explicit and precise concepts is critical for building a systematic science of engineering design. Based on Bunge's scientific ontology, this paper is devoted to developing an explicit and precise concept of function for design science. First, we attempt to clarify the concept of behavior, which is closely related to function and is also shown as an ambiguous concept in engineering. Second, the concept of action is imported from scientific ontology into design science. Third, a scientific ontology based concept of function is proposed, together with an ontology-based functional taxonomy. A case of a function definition of a civil aircraft type demonstrates that the proposed concept of function is more explicit and precise than previous ones, and it can lead to better functional design results.
A joint diagnostic system was established for the diagnosis of laser-driven shock wave experiments. The system has high temporal resolution (time resolution ~12 ps) and high spatial resolution (spatial resolution ~7 μm) and fits for diagnostics of the experiment with small sample size and short time physical process. The joint diagnostic system was applied for shock wave measurement on the Shenguang-II laser facility. The passive shock breakout signal and active diagnostic signal were simultaneously obtained. The temporal measurement reliability of the system was verified using a multi-layered target. The experimental results show that the two measurement results were consistent.
Detailed design is often a time-consuming and experience-dependent engineering process, where various detailed design knowledge can be reused. This paper proposes a formal approach for modeling detailed design knowledge for effective reuse. An extended structure–behavior–function model is developed for representing the structural, behavioral, and functional information in various life cycle periods of a detailed design. Based on the extended structure–behavior–function model, an issue- and solution-based approach is then developed to model the detailed knowledge of a mechanical design. The proposed approach is implemented in a detailed design knowledge modeling system, with a fixture design knowledge modeling as a brief example.
In this work, we succeeded in synthesis of spinel LiMn2O4 via a facile self-template method. The product displays a micro-/nanohybrid structure. Nanoparticles/plates act as the primary nanoblocks to build the secondary microarchitecture. There is the open space between the nanoblocks and the void space between the secondary structures. Electrochemical tests demonstrate that the as-synthesized sample exhibits superior rate capability and high-rate cycleability when contrasted with its solid counterpart. The initial discharge capacity is 126 mAh/g at 0.1 C, 110 mAh/g at 10 C, and 84 mAh/g at 20 C. The discharge capacity retention of about 80% is obtained after 800 cycles at 10 C. The high capacity and excellent cycling life of the material shows its potential for application as high-power batteries. The improved rate capability and cycleability can be attributed to its secondary structure that can facilitate fast Li-insertion/extraction and buffer the volume expansion/contraction upon cycling.