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Previous nutritional studies have shown that insulin regulation is different between DT and A strains of gibel carp. As leptin plays a pivotal role in the effects of insulin, we hypothesised that leptin regulation of glucose and lipid metabolism would differ between the two strains. To test our hypothesis, recombinant human leptin was injected into two strains. The results showed that leptin activated the phosphatidylinositol 3-kinase (PI3K)–protein kinase B (AKT), AMP-activated protein kinase–acetyl coenzyme A carboxylase and Janus kinase 2 (JAK2)–signal transducer and activator of transcription (STAT) signalling pathways in both strains. Hypoglycaemia induced by leptin might be due to higher glucose uptake by the liver and muscles together with enhanced glycolytic potential and reduced gluconeogenic potential. Decreased lipogenesis and up-regulated fatty acid oxidation were induced by leptin. In terms of genotype, the PI3K–AKT signalling pathway was more strongly activated by leptin in the muscle tissue of the A strain, as reflected by the heightened phosphorylation of AKT. Furthermore, glycogen content, glycolytic enzyme activity and gluconeogenic capability were higher in the A strain than the DT strain. Strain A had higher levels of fatty acid synthesis and lipolytic capacity in the liver than the DT strain, but the opposite was true in white muscle. Regarding leptin–genotype interactions, the DT strain displayed stronger regulation of glucose metabolism in the liver by leptin as compared with the A strain. Moreover, a more active JAK2–STAT signalling pathway accompanied by enhanced inhibition of fatty acid synthesis by leptin was observed in the DT strain. Overall, the regulation of glucose and lipid metabolism by leptin differed between the two strains, as expected.
Shifts in the maternal gut microbiota have been implicated in the development of gestational diabetes mellitus (GDM). Understanding the interaction between gut microbiota and host glucose metabolism will provide a new target of prediction and treatment. In this nested case-control study, we aimed to investigate the causal effects of gut microbiota from GDM patients on the glucose metabolism of germ-free (GF) mice. Stool and peripheral blood samples, as well as clinical information, were collected from 45 GDM patients and 45 healthy controls (matched by age and prepregnancy body mass index (BMI)) in the first and second trimester. Gut microbiota profiles were explored by next-generation sequencing of the 16S rRNA gene, and inflammatory factors in peripheral blood were analyzed by enzyme-linked immunosorbent assay. Fecal samples from GDM and non-GDM donors were transferred to GF mice. The gut microbiota of women with GDM showed reduced richness, specifically decreased Bacteroides and Akkermansia, as well as increased Faecalibacterium. The relative abundance of Akkermansia was negatively associated with blood glucose levels, and the relative abundance of Faecalibacterium was positively related to inflammatory factor concentrations. The transfer of fecal microbiota from GDM and non-GDM donors to GF mice resulted in different gut microbiota colonization patterns, and hyperglycemia was induced in mice that received GDM donor microbiota. These results suggested that the shifting pattern of gut microbiota in GDM patients contributed to disease pathogenesis.
The present study aimed to evaluate the status of iodine nutrition and thyroid function in adults, to understand the distribution of thyroid disease in people with autoimmune thyroid disease (AITD) in different water iodine areas and to explore the relationship between serum iodine, urine iodine and thyroid function in people with AITD. A cross-sectional survey was conducted in areas of Shandong Province with different water iodine levels, and subsequently 1225 adults were enrolled from iodine-deficient (ID), iodine-adequate (IA) and iodine-excess (IE) areas. Urinary iodine, water iodine, salt iodine, serum iodine and thyroid function were measured. According to the urine iodine concentration, the ID and IA areas were defined as iodine sufficient and the IE area as iodine excessive. Urine iodine, serum iodine, free thyroxine (FT4) and thyroid-stimulating hormone (TSH) levels were comparatively higher in the IE area. The positive rate of thyroglobulin antibody (19·1 %) and the prevalence of AITD (21·8 %) were higher in the ID areas; the prevalence of subclinical hypothyroidism was lowest in the ID areas (7·3 %) and highest in the IE area (16·3 %). Among the AITD population, urinary iodine concentration, free triiodothyronine, FT4 and TSH had a non-linear correlation with serum iodine; abnormal TSH level, serum iodine concentration > 110 µg/l and goitre were risk factors for AITD in adults, especially females. Our data collectively suggest that universal salt iodisation has improved the iodine nutritional status of the population in ID areas in China. Non-step-by-step iodine fortification may induce the transformation of thyroid autoimmune diseases from recessive-to-dominant in susceptible people. Moreover, enhanced monitoring of thyroid function in people with AITD is important.
In this paper, we report the recent progress on the $1~\text{PW}/0.1~\text{Hz}$ laser beamline of Shanghai Superintense Ultrafast Laser Facility (SULF). The SULF-1 PW laser beamline is based on the double chirped pulse amplification (CPA) scheme, which can generate laser pulses of 50.8 J at 0.1 Hz after the final amplifier; the shot-to-shot energy fluctuation of the amplified pulse is as low as 1.2% (std). After compression, the pulse duration of 29.6 fs is achieved, which can support a maximal peak power of 1 PW. The contrast ratio at $-80~\text{ps}$ before main pulse is measured to be $2.5\times 10^{-11}$. The focused peak intensity is improved by optimizing the angular dispersion in the grating compressor. The maximal focused peak intensity can reach $2.7\times 10^{19}~\text{W}/\text{cm}^{2}$ even with an $f/26.5$ off-axis parabolic mirror. The horizontal and vertical angular pointing fluctuations in 1 h are measured to be 1.89 and $2.45~\unicode[STIX]{x03BC}\text{rad}$, respectively. The moderate repetition rate and the good stability are desirable characteristics for laser–matter interactions. The SULF-1 PW laser beamline is now in the phase of commissioning, and preliminary experiments of particle acceleration and secondary radiation under 300–400 TW/0.1 Hz laser condition have been implemented. The progress on the experiments and the daily stable operation of the laser demonstrate the availability of the SULF-1 PW beamline.
An oral starch administration trial was used to evaluate glucose homoeostasis in grass carp (Ctenopharyngodon idella) and Chinese longsnout catfish (Leiocassis longirostris Günther). Fish were administered with 3 g of a water and starch mixture (with 3:2 ratio) per 100 g body weight after fasting for 48 h. Fish were sampled at 0, 1, 3, 6, 12, 24 and 48 h after oral starch administration. In grass carp, plasma levels of glucose peaked at 3 h but returned to baseline at 6 h. However, in Chinese longsnout catfish, plasma glucose levels peaked at 6 h and returned to baseline at 48 h. The activity of intestinal amylase was increased in grass carp at 1 and 3 h, but no significant change in Chinese longsnout catfish was observed. The activity of hepatic glucose-6-phosphatase fell significantly in grass carp but change was not evident in Chinese longsnout catfish. The expression levels and enzymic activity of hepatic pyruvate kinase increased in grass carp, but no significant changes were observed in the Chinese longsnout catfish. Glycogen synthase (gys) and glycogen phosphorylase (gp) were induced in grass carp. However, there was no significant change in gys and a clear down-regulation of gp in Chinese longsnout catfish. In brief, compared with Chinese longsnout catfish, grass carp exhibited a rapid increase and faster clearance rate of plasma glucose. This effect was closely related to significantly enhanced levels of digestion, glycolysis, glycogen metabolism and glucose-induced lipogenesis in grass carp, as well as the inhibition of gluconeogenesis.
The average power of diode-pumped fiber lasers has been developed deeply into the kW regime in the past years. However, stimulated Raman scattering (SRS) is still a major factor limiting the further power scaling. Here, we have demonstrated the mitigation of SRS in kilowatt-level diode-pumped fiber amplifiers using a chirped and tilted fiber Bragg grating (CTFBG) for the first time. The CTFBG is designed and inscribed in large-mode-area (LMA) fibers, matching with the operating wavelength of the fiber amplifier. With the CTFBG inserted between the seed laser and the amplifier stage, an SRS suppression ratio of
${\sim}10~\text{dB}$
is achieved in spectrum at the maximum output laser power of 2.35 kW, and there is no reduction in laser slope efficiency and degradation in beam quality. This work proves the feasibility and practicability of CTFBGs for SRS suppression in high-power fiber lasers, which is very useful for the further power scaling.
A compact dual ports antenna with high isolation is proposed for handheld radio frequency identification (RFID) reader which is rarely reported in open literatures. Different with conventional handheld RFID reader antennas with single port, the proposed antenna transmits and receives signal separately. The proposed antenna operating with full duplex mode can enhance effectively sensitivity of reader, since the strong transmitting signal of reader with single port is usually highly coupled with weak receiving backscatter signal of tag. The antenna utilizes E-shaped aperture-coupled patch structure that occupies less volume and provides further space-saving efficiency. The height of the proposed antenna is only 6.8 mm and the volume of that is 80 mm × 80 mm × 6.8 mm, which is easy to integrate in handheld RFID readers. The antenna uses two E-shaped coupling apertures to excite two orthogonal modes for dual-polarized operation. High isolation of around −30 dB is obtained by proper arrangement of the length of coupling apertures and the position of the stubs. The measured results show −10 dB matching band and −25 dB isolation band from 2.32 to 2.6 GHz and from 2.3 to 2.55 GHz, respectively. The antenna is suitable for applications in handheld RFID readers.
We present a concept of robust optimisation design for the spring actuator in a 10 kV/12.5 kA vacuum circuit breaker. We assume the breaking and closing velocity characteristics, which are derived form the technical data of the interrupter, as the specifications for the problem, and take the lengths of the connecting rods of the actuator and the stiffness coefficients of the breaking and closing springs as the optimisation variables. The variance between the specifications and the velocities calculated at each breaking and closing point and the maximal variation allowed by the design variables within acceptable tolerances make up the multiple objective function. The optimal parameters for the spring actuator are given by solving a non-linear programming problem with multiple targets and two-level optimisation.
As a promising reinforcement of aluminum alloy, in situ formed Al3Ti particles have attracted more attention in the fabrication of aluminum matrix composites. In our research, in situ Al3Ti/7075 alloy composites were fabricated by adding K2TiF6 salt powders into molten 7075 alloy at 750 °C via casting method. The formation of in situ Al3Ti particles and their effects on the microstructure and mechanical properties of 7075 alloy, including hardness, ultimate tensile strength (UTS), and yield strength (YS), were investigated. The results showed that in situ formed Al3Ti particles were rod-like in morphology, with the average length and width of 15 µm and 5 µm, respectively. Due to the nucleating effect of Al3Ti particles, α-Al crystals of 7075 alloy transferred from dendritic to equiaxed structure in morphology, the size of which decreased obviously as well. Compared with 7075 alloy, the hardness, UTS, and YS of in situ Al3Ti/7075 alloy were improved by 14.3%, 18.1%, and 25.8%, respectively.
Diets supplemented with fish oil (FO), which is rich in n-3 PUFA, have been shown to modify several key risk factors for CVD. The purpose of the present study was to determine the effect of FO supplementation on mitochondrial dynamic protein expression in the endothelium and on endothelial cell function. Male apoE-deficient (apoE− / −) mice (8 weeks old, n 12 per group) were fed a high-fat diet containing 45 % fat (HFD group) or a HFD with partial replacement of lard with 10 % (w/w) FO (FO group) (total EPA and DHA content 64·1 g/kg) for 8 weeks. ApoE− / − mice in the FO group had a greater endothelium-dependent vasorelaxation response to acetylcholine (Ach) than those in the HFD group. The atherosclerotic lesion volume in the aortic sinus of mice in the FO group was 54 % lower than that in the HFD group (P< 0·01). In addition, the aortas isolated from mice in the FO group had higher expression levels of Mfn2 and Opa1 but lower expression levels of Fis1 than those from the HFD group. Compared with mice fed the HFD, those fed the FO diet showed significantly lower levels of mitochondrial oxidative stress, cytochrome c release and caspase-3 activity (each P< 0·05). Furthermore, FO-fed mice displayed increased NO release and availability and enhanced endothelial NO synthase activity compared with HFD-fed mice. Taken together, these results reveal a novel mechanism by which FO protects against endothelial cell dysfunction, which may result in improved mitochondrial dynamics.
We develop a splicing technology of Ti:sapphire crystals for a high-energy chirped pulse amplifier laser system that can suppress the parasitic lasing to improve the amplification efficiency compared to a large-size single Ti:sapphire crystal amplifier. Theoretical investigations on the characteristics of the amplifier with four splicing Ti:sapphire crystals, such as parasitic-lasing suppression and amplification efficiencies, are carried out. Some possible issues resulting from this splicing technology, including spectral modulation, stretching or splitting of the temporal profile, and the sidelobe generation in the spatial domain (near field and far field), are also investigated. Moreover, the feasibility of the splicing technology is preliminarily demonstrated in an experiment with a small splicing Ti:sapphire crystals amplifier. The temporal profile and spatial distribution of the output pulse from the splicing Ti:sapphire crystal amplifier are discussed in relation to the output pulse from a single Ti:sapphire crystal amplifier.
This research discussed how to synthesize submicrometer-sized TiC particulate reinforcement in the molten aluminum melt at low temperature via combustion synthesis by using in situ casting technique. A high temperature preheating treatment of Al–Ti–C pellets was carried out, by which the thermal explosion reaction of the pellets could take place in the pure aluminum melt at 750 °C. The synthesizing temperature of TiC particles was reduced by at least 150 °C compared with the conventional methods. In situ formed TiC particles were spherical in shape and were smaller than 1 µm in size due to the low melting temperature. The emergence of liquid aluminum phase led to the generation and accumulation of plenty of heat in the pellet in a short time due to the reactive diffusion of Al(l)–Ti(s). The formation mechanism of the submicrometer-sized TiC particles in the molten aluminum at low temperature was discussed in this research.
In this paper, a multi-layer model is developed for the purpose of studying nonlinear internal wave propagation in shallow water. The methodology employed in constructing the multi-layer model is similar to that used in deriving Boussinesq-type equations for surface gravity waves. It can also be viewed as an extension of the two-layer model developed by Choi & Camassa. The multi-layer model approximates the continuous density stratification by an -layer fluid system in which a constant density is assumed in each layer. This allows the model to investigate higher-mode internal waves. Furthermore, the model is capable of simulating large-amplitude internal waves up to the breaking point. However, the model is limited by the assumption that the total water depth is shallow in comparison with the wavelength of interest. Furthermore, the vertical vorticity must vanish, while the horizontal vorticity components are weak. Numerical examples for strongly nonlinear waves are compared with laboratory data and other numerical studies in a two-layer fluid system. Good agreement is observed. The generation and propagation of mode-1 and mode-2 internal waves and their interactions with bottom topography are also investigated.
Research was conducted to improve performance of organic light-emitting devices (OLEDs) on flexible polyethylene terephthalate (PET) substrates based on tris-(8-hydroxyquinoline)¨Caluminum (Alq3). Based on double layer structure, indium tin oxide(ITO)/N,N’Diphenyl-N-N’-di(m-tdyl) benzidine (TPD)/Alq3/Al, flexible OLEDs on polyethylene terephthalate (PET) substrates were fabricated by physical vapor deposition (PVD) method, with the Alq3 layer deposited at 90°C , 120°C and 150°C, respectively. It was found that the temperature had great effect on the surface morphology of Alq3 and the devices fabricated at high temperature (150°C) showed a higher external efficiency than those fabricated at low temperature (90°C , 120°C).
Multi wall carbon nanotubes (MWCNTs) doping poly(3,4-ethylene dioxythiophene) (PEDOT) : poly(styrene sulfonate) (PSS) was used as hole injection layer to improve performance of OLEDs based on Alq3. PEDOT:PSS, which was doped by 0.2 wt.%, 0.4 wt.%, 0.6 wt.%, 0.8 wt.% and 1 wt.% MWCNTs, was coated on clean PET substrate with ITO by spin- coating method. The light-emitting layer (Alq3) and cathode layer (Al) were deposited by PVD method. It was found that the electroluminescence (EL) intensity of the OLEDs were highly improved by adopting MWCNTs doping PEDOT:PSS as hole injection layer. The luminous intensity obtained from the device with a concentration of 0.4 wt.% MWCNTs in the PEDOT:PSS layer was three folds as those adopted from device without MWCNTS doping in the PEDOT:PSS layer.
R2MoO6:Eu3+ (R = Gd, Y, La) phosphors were prepared by the Pechini sol-gel process. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), reflectance spectra, photoluminescence (PL) spectra, and lifetimes were used to characterize the resulting phosphors. The results of XRD indicate that all of the R1.96Eu0.04MoO6 (R = Gd, Y, La) phosphors crystallized completely at 800 °C. Y1.96Eu0.04MoO6 and Gd1.96Eu0.04MoO6 are of isomorphous monoclinic (α) structure, while La1.96Eu0.04MoO6 preferentially adopts the tetragonal (γ) form. FE-SEM study reveals that the samples mainly consist of aggregated particles with an average grain size ranging from 100 to 250 nm. The luminescent properties of R2MoO6:Eu3+ (R = Gd, Y, La) phosphors are largely dependent on their structure, grain size, and powder morphology. The isomorphous Y2MoO6:Eu3+ and Gd2MoO6:Eu3+ phosphors show very similar luminescence properties, which differ greatly from that of the La2MoO6:Eu3+ phosphor.
We have fabricated a new ferroelectric memory FET, which consists of the Au/Pb(Zr0.52Ti0.48)O3/SiO2/Si gate structure. Ferroelectric PZT thin film with a thickness of 250~400 nm was prepared by using Excimer Laser Ablation Deposition. Silicon oxide successfully served as a buffer layer between ferroelectric and Si substrate to suppress the charge injection and prevent Pb interdiffusion. Electrical properties of the ferroelectric FET have been characterized through both the Capacitance vs. Voltage(C-V) and Current vs. Voltage(I-V) measurements, showing a typical memory characteristics of FET devices, i.e., the ON state and OFF state were nonvolatile for about thirty minutes and several hours, respectively.
Reports of the Tibet red deer, a subspecies of Cervus elaphus, have been so few in recent years that there were fears that the animal was extinct. A survey in a mountainous region of south-east Tibet in October 1995 found evidence that a few deer survive in one small area and possibly two others in high-altitude valleys of the tributaries of the Subansiri River. The most exciting finding of the survey, however, was an estimated 200-strong population of this deer in high rolling hills near the village of Zhenqi, north of the Yarlung Tsangpo River. This is the only known viable population of the deer and, although some hunting occurs, including by professional poachers from outside Tibet, the fact that it survives is an indication of the tolerance of the local people. The Tibet Forest Bureau has agreed to fund guards and to establish a reserve for the deer in co-operation with local people.