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l-Carnitine is essential for mitochondrial β-oxidation and has been used as a lipid-lowering feed additive in humans and farmed animals. d-Carnitine is an optical isomer of l-carnitine and dl-carnitine has been widely used in animal feeds. However, the functional differences between l- and d-carnitine are difficult to study because of the endogenous l-carnitine background. In the present study, we developed a low-carnitine Nile tilapia model by treating fish with a carnitine synthesis inhibitor, and used this model to investigate the functional differences between l- and d-carnitine in nutrient metabolism in fish. l- or d-carnitine (0·4 g/kg diet) was fed to the low-carnitine tilapia for 6 weeks. l-Carnitine feeding increased the acyl-carnitine concentration from 3522 to 10 822 ng/g and alleviated the lipid deposition from 15·89 to 11·97 % in the liver of low-carnitine tilapia. However, as compared with l-carnitine group, d-carnitine feeding reduced the acyl-carnitine concentration from 10 822 to 5482 ng/g, and increased lipid deposition from 11·97 to 20·21 % and the mRNA expression of the genes involved in β-oxidation and detoxification in the liver. d-Carnitine feeding also induced hepatic inflammation, oxidative stress and apoptosis. A metabolomic investigation further showed that d-carnitine feeding increased glycolysis, protein metabolism and activity of the tricarboxylic acid cycle and oxidative phosphorylation. Thus, l-carnitine can be physiologically utilised in fish, whereas d-carnitine is metabolised as a xenobiotic and induces lipotoxicity. d-Carnitine-fed fish demonstrates increases in peroxisomal β-oxidation, glycolysis and amino acid degradation to maintain energy homeostasis. Therefore, d-carnitine is not recommended for use in farmed animals.
Atomic force microscopy (AFM) is typically used for analysis of relatively flat surfaces with topographic features smaller than the height of the AFM tip. On flat surfaces, it is relatively easy to find the object of interest and deconvolute imaging artifacts resulting from the finite size of the AFM tip. In contrast, AFM imaging of three-dimensional objects much larger than the AFM tip height is rarely attempted although it could provide topographic information that is not readily available from two-dimensional imaging, such as scanning electron microscopy. In this paper, we report AFM measurements of a vertically-mounted razor blade, which is taller and sharper than the AFM tip. In this case, the AFM height data, except for the data collected around the cutting edge of the blade, reflect the shape of the AFM tip. The height data around the apex area are effectively the convolution of the AFM tip and the blade cutting edge. Based on computer simulations mimicking an AFM tip scanning across a round sample, a simple algorithm is proposed to deconvolute the AFM height data of an object taller and sharper than the AFM tip and estimate its effective curvature.
The Inner Mongolian Plateau lies along the northern limit reached by the East Asian summer monsoon. This geographic setting makes it especially sensitive to environmental change and an excellent site for understanding Quaternary East Asian monsoon variability. In this study we present new results of hydrogen isotopic compositions of fatty acids extracted from sediments, which were used to construct Holocene paleoprecipitation (or moisture) changes in Northern China. The hydrogen isotopic composition (D/H ratio) of n-acids in the sedimentary sequence of the Duoerji peat, Inner Mongolia, was determined with gas chromatography and mass spectrometry. Changes in the precipitation from middle Inner Mongolia are recorded by the D/H ratio of n-C20, n-C22, n-C24, n-C26, n-C28 acids (δD). From 10–9 ka, the relatively high δD values indicate reduced precipitation in the Early Holocene. Subsequently, increased precipitation is reflected by reduced δD values from 9–5.5 ka. After 5.5 ka, gradually increasing δD values record an overall decrease in precipitation. The precipitation trends established for the Duoerji sequence are consistent with other major paleoclimate proxies in the East Asian monsoon region, especially with a distinct Holocene optimum of increased monsoonal activity from 9–5.5 ka. The δD resulting paleo-precipitation record clearly shows that the Holocene climate in Northern China is basically controlled by the insolation changes.
Astrophysical collisionless shocks are amazing phenomena in space and astrophysical plasmas, where supersonic flows generate electromagnetic fields through instabilities and particles can be accelerated to high energy cosmic rays. Until now, understanding these micro-processes is still a challenge despite rich astrophysical observation data have been obtained. Laboratory astrophysics, a new route to study the astrophysics, allows us to investigate them at similar extreme physical conditions in laboratory. Here we will review the recent progress of the collisionless shock experiments performed at SG-II laser facility in China. The evolution of the electrostatic shocks and Weibel-type/filamentation instabilities are observed. Inspired by the configurations of the counter-streaming plasma flows, we also carry out a novel plasma collider to generate energetic neutrons relevant to the astrophysical nuclear reactions.
Familial monozygotic (MZ) twinning reports are rare around the world, and we report a four-generation pedigree with seven recorded pairs of female MZ twins. Whole-genome sequencing of seven family members was performed to explore the featured genetic factors in MZ twins. For variations specific to MZ twins, five novel variants were observed in the X chromosome. These candidates were used to explain the seemingly X-linked dominant inheritance pattern, and only one variant was exonic, located at the 5′UTR region of ZCCHC12 (chrX: 117958597, G > A). Besides, consistent mitochondrial DNA composition in the maternal linage precluded roles of mitochondria for this trait. In this pedigree, autosomes also contain diverse variations specific to MZ twins. Pathway analysis revealed a significant enrichment of genes carrying novel SNVs in the epithelial adherens junction-signaling pathway (p = .011), contributed by FGFR1, TUBB6, and MYH7B. Meanwhile, TBC1D22A, TRIOBP, and TUBB6, also carrying similar SNVs, were involved in the GTPase family-mediated signal pathway. Furthermore, gene-set enrichment analysis for 533 genes covered by copy number variations specific to MZ twins illustrated that the tight junction-signaling pathway was significantly enriched (p < .001). Therefore, the novel changes in the X chromosome and the provided candidate variants across autosomes may be responsible for MZ twinning, giving clues to increase our understanding about the underlying mechanism.
As a promising new way to generate a controllable strong magnetic field, laser-driven magnetic coils have attracted interest in many research fields. In 2013, a kilotesla level magnetic field was achieved at the Gekko XII laser facility with a capacitor–coil target. A similar approach has been adopted in a number of laboratories, with a variety of targets of different shapes. The peak strength of the magnetic field varies from a few tesla to kilotesla, with different spatio-temporal ranges. The differences are determined by the target geometry and the parameters of the incident laser. Here we present a review of the results of recent experimental studies of laser-driven magnetic field generation, as well as a discussion of the diagnostic techniques required for such rapidly changing magnetic fields. As an extension of the magnetic field generation, some applications are discussed.
We present laboratory measurement and theoretical analysis of silicon K-shell lines in plasmas produced by Shenguang II laser facility, and discuss the application of line ratios to diagnose the electron density and temperature of laser plasmas. Two types of shots were carried out to interpret silicon plasma spectra under two conditions, and the spectra from 6.6 Å to 6.85 Å were measured. The radiative-collisional code based on the flexible atomic code (RCF) is used to identify the lines, and it also well simulates the experimental spectra. Satellite lines, which are populated by dielectron capture and large radiative decay rate, influence the spectrum profile significantly. Because of the blending of lines, the traditional
value are not applicable in diagnosing electron temperature and density of plasma. We take the contribution of satellite lines into the calculation of line ratios of He-
lines, and discuss their relations with the electron temperature and density.
The object of this paper is to prove a version of the Beurling–Helson–Lowdenslager invariant subspace theorem for operators on certain Banach spaces of functions on a multiply connected domain in
. The norms for these spaces are either the usual Lebesgue and Hardy space norms or certain continuous gauge norms. In the Hardy space case the expected corollaries include the characterization of the cyclic vectors as the outer functions in this context, a demonstration that the set of analytic multiplication operators is maximal abelian and reflexive, and a determination of the closed operators that commute with all analytic multiplication operators.
A non-precious metal catalytic system of Fe-doped Ta2O5 is developed by pulsed laser deposition toward efficient oxygen evolution reaction (OER). The optimal Fe concentration is determined to be 5 at.% for optimized OER activity via a series of electrochemical characterizations. The 5 at.% Fe-doped Ta2O5 nanolayer possesses a low onset overpotential of 0.22 V, an overpotential of 0.38 V at 10 mA/cm2 and a Tafel slope of 54 mV/dec. Comprehensive first-principles calculations attribute the enhanced OER activity to the substitutional FeTa dopants, which generate a new active OER site on surface and simultaneously accelerate electron transfer over oxygens.
This research was designed for the first time to investigate the photocatalytic activities of MoO3/g-C3N4 composite in converting CO2 to fuels under simulated sunlight irradiation. The composite was synthesized using a simple impregnation-heating method and MoO3 nanoparticles was in situ decorated on the g-C3N4 sheet. Characterization results indicated that the introduction of MoO3 nanoparticles into g-C3N4 fabricated a direct Z-scheme heterojunction structure. The effective interfacial charge-transfer across the heterojunction significantly promoted the separation efficiency of charge carriers. The optimal CO2 conversion rate of the composite reached 25.6 μmol/(h gcat), which was 2.7 times higher than that of g-C3N4. Additionally, the synthesized MoO3/g-C3N4 also presented excellent photoactivity in RhB degradation under visible-light irradiation.
Non-biomineralizing Ediacaran macrofossils are rare in carbonate facies, but they offer valuable information about their three-dimensional internal anatomy and can broaden our view about their taphonomy and palaeoecology. In this study, we report a new Ediacaran fossil, Curviacus ediacaranus new genus and species, from bituminous limestone of the Shibantan Member of the Dengying Formation in the Yangtze Gorges area of South China. Curviacus is reconstructed as a benthic modular organism consisting of serially arranged and crescent-shaped chambers. The chambers are confined by chamber walls that are replicated by calcispars, and are filled by micritic sediments. Such modular body construction is broadly similar to the co-occurring Yangtziramulus zhangii and other Ediacaran modular fossils, such as Palaeopascichnus. The preservation style of Curviacus is similar to Yangtziramulus, although the phylogenetic affinities of both genera remain unresolved. The new fossil adds to the diversity of Ediacaran modular organisms.
As a well-known phosphatized Lagerstätte, the Ediacaran Weng'an biota in central Guizhou Province of South China contains diverse acanthomorphic acritarchs, algal thalli, tubular microfossils as well as various spheroidal fossils. These fossils provide crucial palaeontological evidence for the radiation of multicellular eukaryotes after the termination of the Neoproterozoic global glaciation. While the Weng'an biota is generally considered as early Ediacaran in age on the basis of phosphorite Pb–Pb isochron ages ranging from 572 Ma to 599 Ma, the reliability and accuracy of these age data have been questioned and some geologists have proposed that the Weng'an biota may be younger than 580 Ma instead. Here we report a SIMS zircon U–Pb age of 609 ± 5 Ma for a tuffaceous bed immediately above the upper phosphorite unit in the Doushantuo Formation at Zhangcunping, Yichang, South China. Litho-, bio- and chemostratigraphic correlations suggest that the upper phosphorite unit at Zhangcunping can be well correlated with the upper phosphorite unit at Weng'an, which is the main horizon of the Weng'an biota. We therefore conclude that the Weng'an biota could be as old as 609 ± 5 Ma.
The objective of this study was to investigate the effects of l-carnitine and/or maize distillers dried grains with solubles (DDGS) in diets of gestating and lactating sows on the intestinal barrier functions of their offspring. The experiment was designed as a 2×2 factorial with two dietary treatments (soyabean meal v. DDGS) and two l-carnitine levels (0 v. 100 mg/kg in gestating diets and 0 v. 200 mg/kg in lactating diets). Sows (Landrace×Large White) with an average parity of 4·2 with similar body weight were randomly assigned to four groups of thirty each. Dietary supplementation with l-carnitine increased the total superoxide dismutase activity but decreased the concentration of malondialdehyde of the jejunal mucosa in newborn piglets and weaning piglets on day 21. Dietary supplementation with l-carnitine decreased the concentrations of IL-1β, IL-12 and TNF-α in the jejunal mucosa of newborn piglets and decreased the concentrations of IL-6 and TNF-α in the jejunal mucosa of weaning piglets on day 21. There was an interaction between dietary treatment and l-carnitine on the bacterial numbers of total eubacteria in the digesta of caecum in weaning piglets on day 21. Bacterial numbers of total eubacteria in weaning piglets on day 21 were significantly increased by l-carnitine only in soyabean meal diet, but there was no significant effect of l-carnitine in DDGS-based diet. Dietary supplementation with l-carnitine increased the bacterial numbers of Lactobacillus spp. and bifidobacteria spp. in the digesta of caecum in weaning piglets on day 21. Dietary supplementation with l-carnitine in sows affected the expression of tight junction proteins (claudin 1, zonula occludens-1 (ZO-1) and occludin) in the jejunal mucosa of their offspring by increasing the expression of ZO-1 mRNA in the jejunal mucosa of newborn piglets, and by increasing the expression of ZO-1 and occludin mRNA in the jejunal mucosa of weaning piglets on day 21. In conclusion, dietary supplementation with l-carnitine in gestating and lactating sows had positive effects on intestinal barrier functions of newborn piglets and weaning piglets on day 21, but it did not have effects on intestinal barrier functions of growing–finishing pigs in the filial generation. There were no effects of dietary treatment of sows on intestinal barrier functions in their offspring.
Hot deformation and dynamic recrystallization (DRX) behavior of the Cu–Cr–Zr–Ag alloy were studied by hot compressive tests in the 650–950 °C temperature and 0.001–10 s−1 strain rate ranges using Gleeble-1500D thermomechanical simulator. The activation energy of deformation was determined as Q = 343.23 kJ/mol by the regression analysis. The critical conditions, including the critical strain and stress, for the occurrence of DRX were determined based on the alloy strain hardening rate. The critical strain related to the onset of DRX decreases with temperature. The ratios of the critical to peak stress and critical to peak strain were also identified as 0.91 and 0.49, respectively. The evolution of DRX microstructure strongly depends on the deformation conditions in terms of temperature and strain rate. Dislocation generation and multiplication are the main hot deformation mechanisms for the alloy. The addition of Ag can refine the grain and effectively improve the DRX of the Cu–Cr–Zr alloy. It can also inhibit the growth of the DRX grains at 950 °C deformation temperature, making the microstructure much more stable.
Increasing dietary Ca intake may prevent the excessive mobilisation of bone mineral in nursing mothers. We aimed to investigate whether higher Ca intake could positively modulate the bone mineral changes in Chinese postpartum lactating women. The study was a 12-month randomised, double-blinded, parallel group trial conducted over 12 months. A total of 150 postpartum women were randomly selected to receive either 40 g of milk powder containing 300 mg of Ca and 5 μg of vitamin D (Low-Ca group) or same milk powder additionally fortified with 300 mg of Ca (Mid-Ca group) or 600 mg of Ca (High-Ca group). Bone mineral density (BMD) for the whole body, the lumbar spine, the total left hip and its sub-regions was measured using dual-energy X-ray absorptiometry. A total of 102 subjects completed the whole trial. The duration of total lactating time was 7·9 (sd 2·8) months on average. The intention-to-treat analysis yielded the following mean percentage changes in BMD for the whole body, the lumbar spine and the total left hip, respectively: −0·93 (sd 1·97), 2·11 (sd 4·90) and −1·60 (sd 2·65) % for the Low-Ca group; −0·56 (sd 1·89), 2·21 (sd 3·77) and −1·43 (sd 2·30) % for the Mid-Ca group; and −0·44 (sd 1·67), 2·32 (sd 4·66) and −0·95 (sd 4·08) % for the High-Ca group. The differences between the groups were not statistically significant (P: 0·5–0·9). The results of the complete case analysis were similar. In sum, we found no significant differences in the bone mineral changes from baseline to 12 months in postpartum lactating women consuming milk powder fortified with different levels of Ca.
Routine early integration of palliative care with advanced cancer management is not yet a part of standard practice in many countries, including mainland China. Whether patients in China suffering from advanced cancer are referred to palliative care services in a timely manner remains unclear. We sought to investigate the timing of palliative care referral of Chinese cancer patients at our center and its predictors.
Retrospective medical data including demographic characteristics and referral information were collected for analysis. A total of 759 patients referred to our palliative care unit (PCU) from January of 2007 to December of 2013 were included in the final analysis.
The mean age of the 759 patients included in the study was 62.89 years (range 61.95–63.82). Some 369 patients (48.6%) were male and 559 (73.6%) Shanghainese (indigenous). Lung cancer (17.9%) was the most common diagnosis. The time interval since enrollment into the PCU until a patient's death (length of stay, LOS) was calculated. A longer LOS indicated earlier referral to inpatient PC services. The median LOS was 21 days (CI95% = 19.79–22.21). Multivariate analysis showed that whether or not the patient was indigenous (p = 0.002) and younger than 65 (p = 0.031) were independent factors for a longer LOS. Such other characteristics as gender and primary cancer type bore no relationship to LOS.
Significance of results:
Our findings demonstrate that Chinese cancer patients are referred relatively late in the course of their disease to inpatient palliative care services. To overcome the barriers to early integration of palliative care into a patient's treatment plan, accurate information about palliative care must be provided to both oncologists and patients via comprehensive and systematic educational programs.
In the modern age of the digital world, gigantic amounts of data have been recorded or collected. It remains a great challenge to process and analyze the “big data”. Many neurophysiological, physiological, clinical and behavioral data are dynamic by the nature of the experiments or the way they are collected. These signals could be complex, noisy, and often multivariate and multimodal. How to develop efficient statistical methods to characterize these data and extract information that reveals underlying biological or physiological mechanisms remains an active and important research topic. In recent years, numerous advanced computational statistics, signal processing, and machine-learning methods have been developed and there is rapidly growing interest in applying these methods to data analysis in neuroscience, physiology and medicine.
The state space model (SSM) is referred to a class of probabilistic graphical models (Koller & Friedman 2009), which describe the probabilistic dependence between the latent state variable and the observed measurement. The state or the measurement can be either continuous or discrete. The term “state space” originated in 1960s in the area of control engineering (Kalman 1960). SSM provides a general framework for analyzing deterministic and stochastic dynamical systems that are measured or observed through a stochastic process. The SSM framework has been successfully applied in engineering, statistics, computer science and economics to solve a broad range of dynamical systems problems. The most celebrated examples of SSM include the linear dynamical system and the associated inference algorithm: Kalman filter (Kalman 1960), and the hidden Markov model (HMM) (Rabiner 1989). Despite plenty of successful examples applying state space analyses to neural and clinical data, there remain many challenges in data analysis, for either developing new mathematical theories and statistical models, or developing efficient algorithms tuned for large-scale data sets, or catering for highly complex (multimodal or multiscale) and nonstationary data. In order to pave the way for further advancement in these research areas, it is important to recognize these challenges and exchange new ideas among researchers and practitioners.
It is important to point out that the modeling and analysis principles discussed in this book are general and equally valuable for time series analyses in many other disciplines, such as climatology, politics, finance, chemical engineering, consumer marketing and computer networking.