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A novel tetragonal B2CO structure (tP16-B2CO), formed by strong covalent sp2–sp3 B–C and B–O bonds, was predicted with aid of an unbiased structure searching method. With the energy lower than those of previously proposed candidates, except oI16-B2CO, tP16-B2CO was identified as the thermodynamic metastable phase for B2CO compound. The elastic matrix and phonon dispersion spectra declare that tP16-B2CO is mechanically and dynamically stable. The electronic band structure calculation at ambient pressure and a series of high pressure has manifested the indirect semiconducting and band gap increases first and then decreases with pressure increases. The calculation of mechanical properties such as hardness and stress–strain relations of tP16 structure revealed its common hard nature with high hardness of 23.19 GPa and anisotropy with the max stress along  is far higher than that along .
In this work, two types of zinc adipate β-nucleating agents, Adi-Zn(OH)2 (1:1) and Adi-ZnO (1:1), for polypropylene (PP) were prepared and their performances were evaluated and compared with commercial β-nucleating agent (named CNA). Results showed that Adi-Zn(OH)2 (1:1) was more effective in promoting PP to form β-crystals and improving the impact strength of PP in the range of nucleating agent addition (0–0.4 wt%). Based on these findings, the ratio of adipic acid to zinc hydroxide and the nonisothermal crystallization kinetics of the optimum ratio of adipic acid to zinc hydroxide were systematically studied; results showed that at 0.2 wt%, Adi-Zn(OH)2 (1:2), the nucleated PP displayed the highest impact strength, which was 2.6 times that of pure PP and 42% higher than that of CNA. Besides, Adi-Zn(OH)2 (1:2) could also afford to induce the formation of a high content of β-crystals and shorten the crystallization half time (t1/2) and accelerate the crystallization of PP.
Above-threshold ionization (ATI) is one of the most fundamental processess when atoms or molecules are subjected to intense laser fields. Analysis of ATI process in intense laser fields by a Wigner-distribution-like (WDL) function is reviewed in this paper. The WDL function is used to obtain various time-related distributions, such as time-energy distribution, ionization time distribution, and time-emission angle distribution and so on, of atoms in laser field pulses with different laser parameters. For the linearly polarized laser pulses, the time-energy distribution intuitively shows from a quantum point of view the relationship between the ionization moment and the final energy and clearly reveals the origin of interference structures in the photoelectron spectrum. In particular, for linearly polarized few-cycle laser pulses, all calculated distributions show the dependence of electron behavior on the ionization time, emission direction, and carrier-envelope phase (CEP). For elliptically polarized few-cycle pulses, we calculate the angular distribution, ionization time distribution, and time-emission distribution, which are compared with the semiclassical calculations. Analysis shows that the offset angle (difference between positions of the peaks in the angular distributions obtained by two methods) in the angular distributions does not correspond to the offset time (difference between positions of the peaks in the ionization time distributions obtained by two methods) in the ionization time distributions, which implies that the attosecond angular streaking technique based on this correspondence between the offset angle and time is in principle inaccurate. Furthermore, the offset time cannot be interpreted as tunneling time.
Flaxseed oil is rich in ɑ-linolenic acid (ALA), which is the metabolic precursor of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). This study investigated the effect of flaxseed oil supplementation on lipopolysaccharide (LPS)-induced muscle atrophy and carbohydrate oxidation impairment in a piglet model. Twenty-four weaned pigs were used in a 2 × 2 factorial experiment including dietary treatment (5% corn oil vs. 5% flaxseed oil) and LPS challenge (saline vs. LPS). On day 21 of treatment, the pigs were injected intraperitoneally with 100 μg/kg BW LPS, or sterile saline. At 4 h after injection, blood, gastrocnemius muscle and longissimus dorsi (LD) muscle were collected. Flaxseed oil supplementation increased ALA, EPA, total n-3 polyunsaturated fatty acids contents, protein/DNA ratio, and pyruvate dehydrogenase complex (PDC) quantity in muscles (p<0.05). In addition, flaxseed oil reduced mRNA expression of toll-like receptor (TLR) 4 and nucleotide-binding oligomerization domain protein (NOD) 2 and their downstream signaling molecules in muscles, and decreased plasma concentrations of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-8, and mRNA expression of TNF-α, IL-1β and IL-6 (p<0.05). Moreover, flaxseed oil inclusion increased the ratios of phosphorylated Akt 1/ total Akt 1 and phosphorylated forkhead Box O (FOXO) 1/ total FOXO1, and reduced mRNA expression of FOXO1, muscle RING finger (MuRF) 1, and pyruvate dehydrogenase kinase (PDK) 4 in muscles (p<0.05). These results suggest that flaxseed oil might have a positive effect on alleviating muscle protein loss and carbohydrates oxidation impairment induced by LPS challenge through regulation of TLR4/NOD and Akt/FOXO signaling pathway.
Polymer redox-active materials (redoxmers) have numerous applications in the emerging electrochemical energy storage systems due to their structural versatility, fast-cycling ability, high theoretical capacity as electrode materials, sustainability, and recyclability. This review examines recent developments in improving the cycling performance of such materials and provides a vista on the future research directions.
A credit default swap (CDS) is an exchange of premium payments for a compensation for the occurrence of a credit event. Counterparty risks refer to defaults of parties holding CDS contracts. In this paper we develop a valuation/pricing model for a CDS subject to counterparty risks. Using the Cox–Ingersoll–Ross (CIR) model for interest rate and first arrival times of Poisson processes with variable intensities for the occurrences of credit default and counterparty defaults, we derive a mathematical formulation and make a full theoretical investigation. In addition, we develop a full theory for the corresponding infinite horizon problem and establish its connection with the asymptotic long expiry behaviour of finite horizon problem. Furthermore, we establish a connection between two major frameworks for default times: the structure model approach and the intensity model approach. We show that a solution of the structure model can be obtained as the limit of a sequence of solutions of intensity models. Regarded as an important theoretical development, we remove a constraint typically imposed on the parameters of the CIR model; that is, the well-posedness (existence, uniqueness and continuous dependence of parameters) of the mathematical model holds for any empirically calibrated parameters for the CIR model.
This study compared the protective effect of sodium selenite (SS) and selenomethionine (SeMet) on heat stress (HS) invoked porcine IPEC-J2 cellular damage and integrate potential roles of corresponding selenoprotein. Cells were cultured at 37 oC until 80% conﬂuence, and then subjected to four different conditions for 24 h: at 37 oC (Control), 41.5 oC (HS), 41.5 oC supplied with 0.42 µmol Se/L SS (SS) or SeMet (SeMet). HS significantly decreased cell viability, up-regulated mRNA and protein levels of HSP70, and down-regulated mRNA and protein levels of tight junction-related proteins (CLDN-1 and ZO-1). HS induced cells injury was associated with the up-regulation (P < 0.05) of 6 inflammation-related genes and 14 selenoprotein encoding genes, and down-regulation (P < 0.05) of 2 inflammation-related genes and 5 selenoprotein encoding genes. Compared with the HS group, SS and SeMet supplementation resulted in an increase (P < 0.05) in cell viability, decreases (P < 0.05) mRNA expression of HSP70 and 6 inflammation-related genes, and rescue (P < 0.05) of mRNA and protein levels of CLDN-1 and ZO-1. SS and SeMet supplementation changes expressions of 19 selenoprotein encoding genes in cells affected by HS. Both Se supplementation significantly recovered the protein level of GPX1 and increased SELP in the IPEC-J2 cells under HS, respectively. In summary, Se supplementation alleviated the negative impact of HS on IPEC-J2 cells, and their cellular protective effect was associates with regulation expression of selenoproteins, SeMet exhibited a better protective effect.
Echinococcus granulosus sensu stricto (s.s.), Echinococcus multilocularis and Echinococcus canadensis are the common causes of human echinococcosis in China. An accurate species identification tool for human echinococcosis is needed as the treatments and prognosis are different among species. The present work demonstrates a method for the simultaneous detection of these three Echinococcus species based on multiplex polymerase chain reaction (mPCR). Specific primers of this mPCR were designed based on the mitochondrial genes and determined by extensive tests. The method can successfully detect either separated or mixed target species, and generate expected amplicons of distinct size for each species. Sensitivity of the method was tested by serially diluted DNA, showing a detection threshold as less as 0.32 pg for both E. granulosus s.s. and E. canadensis, and 1.6 pg for E. multilocularis. Specificity assessed against 18 other parasites was found to be 100% except weakly cross-react with E. shiquicus. The assay was additionally applied to 69 echinococcosis patients and 38 healthy persons, confirming the high reliability of the method. Thus, the mPCR described here has high application potential for clinical identification purposes, and can further provide a useful tool for evaluation of serology and imaging method.
Laser pulses of 200 ps with extremely high intensities and high energies are sufficient to satisfy the demand of shock ignition, which is an alternative path to ignition in inertial confinement fusion (ICF). This paper reports a type of Brillouin scheme to obtain high-intensity 200-ps laser pulses, where the pulse durations are a challenge for conventional pulsed laser amplification systems. In the amplification process, excited Brillouin acoustic waves fulfill the nonlinear optical effect through which the high energy of a long pump pulse is entirely transferred to a 200-ps laser pulse. This method was introduced and achieved within the SG-III prototype system in China. Compared favorably with the intensity of
in existing ICF laser drivers, a 6.96-
pulse with a width of 170 ps was obtained in our experiment. The practical scalability of the results to larger ICF laser drivers is discussed.
Nano-sized TiN-reinforced Ti metal matrix composites were fabricated by powder metallurgical route, which includes high-energy ball milling pretreatment and subsequent hot-press sintering treatment. The phase composition and microstructure of the sintered samples were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Results showed that N2 was absorbed and solubilized into TiH2 by milling pretreatment, and TiN was formed during sintering process and was fine to a grain size of 20–100 nm. The final phase composition of the composites was αTi, βTi, and TiN with solution N in matrix. Mechanical tests showed that with increasing milling time, the hardness of the composites increased by 31, 58, 93, and 101% compared with pure Ti. The compressive strength initially increased and later decreased to 2440 and 2120 MPa when milled for 1.5 and 2 h, respectively.
Higher fiber intake reduced all-cause and cardiovascular mortality among healthy population, but such data in dialysis patients are limited. We aimed to examine these associations in patients on peritoneal dialysis. This single-center prospective cohort study enrolled 881 incident PD patients between October 2002 and August 2014. All patients were followed until death, transfer to hemodialysis, renal transplantation or until being censored in June 2018. Demographic data were collected at baseline. Biochemical, dietary, and nutrition data were examined at baseline and thereafter at regular intervals to calculate the average values throughout the study. The outcomes were defined as all-cause and cardiovascular death. Cox proportional regression models were applied to explore the relationship between fiber intake and outcomes. Participants with higher fiber intake were more likely to be younger, male, and having better residual renal function and serum lipids at baseline. They were prone to maintain better nutrient status, higher blood pressure and lower inflammatory status at baseline and afterward. Neither baseline nor time-averaged fiber intake did show protective effects on all-cause mortality after multivariate adjustment in the whole cohort. Among non-diabetic PD patients, an independent association between fiber intake and all-cause mortality was found, in which each 1g/day of increase in time-averaged fiber intake correlated to 13% of reduction in all-cause mortality. We did not observe any benefits of fiber intake in the CVD mortality for both whole cohort and subgroups. This study revealed that higher dietary fiber intake appeared to have a protective effect on all-cause mortality in non-diabetic PD patients, which suggest that PD patients should be encouraged to eat a diet rich in fibers.
In the present work, Mo was added to an Al–Si–Mg foundry alloy to study its influence on the evolution of dispersoids during various heat treatments. The microhardness and the elevated-temperature tensile properties and creep resistance were measured to evaluate the contribution of dispersoids. Results showed that the addition of Mo greatly promoted the formation of α-dispersoids. During solution treatment, the formation of α-dispersoids started after 8 h at 500 °C. At high temperature (540 °C), the coarsening of dispersoids with increasing time became predominant. The optimum condition of dispersoids can be reached by 520 °C/12 h or 500 °C/4 h + 540 °C/2 h, leading to the highest differences in microhardness between the Mo-containing alloy and base alloy. The tensile strengths were improved at both room temperature and elevated temperatures, while the elongation at elevated temperature was greatly increased. The creep resistance at elevated temperature is further enhanced due to the Mo addition.
The fenofibrate functions in mammals could be affected by many factors such as dietary nutrient levels and physiological status. However, this phenomenon has not been well studied in fish. The goal of our study was to investigate the effect of dietary protein contents on metabolic regulation of fenofibrate in Nile tilapia. An 8-week experiment was conducted to feed fish with four diets at two protein levels (28% and 38%) with or without the supplementation of fenofibrate (200 mg/kg body weight/day). After the trial, the body morphometric parameters, plasma biochemical parameters and qPCR data were examined. These results showed that fenofibrate significantly reduced the feeding intake and weight gain rate, increased the oxidative stress (increased plasma methane dicarboxylic aldehyde, MDA) and liver/body ratio (increased hepatosomatic index, HSI) in the LP (low protein)-fed fish. In contrast, fenofibrate exhibited a lipid-lowering (reduced hepatic lipid) effect and up-regulated the expressions of the genes related to lipid catabolism, transport and anabolic metabolism in the HP (high protein) fed-fish. The present study suggested that lipid-lowering effect of fenofibrate would be strengthened in the fish fed with HP diet containing high energy, but in the fish fed with the LP diet containing low energy, the fenofibrate treatment would cause adverse effects for metabolism. Taking together, our study showed that the metabolic regulation of fenofibrate in Nile tilapia was not only dependent on feed energy content, but also dependent on dietary nutrient composition, such as dietary protein and/or lipid levels.
The secondary instabilities of stationary cross-flow vortices in a Mach 6 swept wing flow are studied using Floquet theory. High-frequency secondary instability modes of ‘y’ mode on top of stationary cross-flow vortices, and ‘z’ mode concentrating on the shoulder of the stationary cross-flow vortex are found. The most unstable secondary instability mode is always the ‘z’ mode as in incompressible swept wing flows. A new secondary instability mode concentrating on the trough of the stationary cross-flow vortex is found. The balance analysis of disturbance kinetic energy shows that the new mode belongs to the class of ‘y’ mode. The growth rate of the new ‘y’ mode located on the trough of the stationary cross-flow vortex is significantly larger than that of the ‘y’ mode on top of the stationary cross-flow vortex, and is comparable with the growth rate of the ‘z’ mode. It is also found that the new ‘y’ mode with higher frequency can evolve into the ‘z’ mode further downstream. The role of the pressure fluctuation term, including the pressure diffusion and pressure dilatation, in the energy production of secondary instability modes, is also investigated. It is shown that the pressure diffusion will only enhance the growth rate of the ‘z’ mode with higher frequency, but has little influence on other types of secondary instability mode. However, the pressure dilatation term arising from non-vanishing velocity divergence will reduce the growth rates of all secondary instability modes.
Cryoconite is a dark-coloured granular sediment that contains biological and mineralogical components, and it plays a pivotal role in geochemistry, carbon cycling and glacier mass balance. In this work, we collected cryoconite samples from Laohugou Glacier No. 12 (LHG) on the north-eastern Tibetan Plateau during the summer of 2015 and measured the spectral albedo. To explore the impacts of this sediment on surface ablation, the ice melting differences between the cryoconite-free (removed) ice and the intact layers were compared. The results showed that the mean concentrations of black carbon (BC), organic carbon (OC) and total iron (Fe) in the LHG cryoconite were 1.28, 11.18 and 39.94 mg g−1, respectively. BC was found to play a stronger role in solar light adsorption than OC and free Fe. In addition, ice covered by cryoconite exhibited the lowest mean reflectance (i.e., <0.1). Compared with the cryoconite-free ice surface, cryoconite effectively absorbed solar energy and enhanced glacial melting at a rate of 2.27–3.28 cm d−1, and free Fe, BC and OC were estimated to contribute 1.01, 0.99 and 0.76 cm d−1, respectively. This study provides important insights for understanding the role of cryoconite in the glacier mass balance of the northern Tibetan Plateau.