Dietary fat supplementation relieves cold temperature-induced energy stress through AMPK-mediated mitochondrial homeostasis in pigs

Background Cold stress has negative effects on the growth and health of mammals, and has become a factor restricting livestock development at high latitudes and on plateaus. The gut-liver axis is central to energy metabolism, and the mechanisms by which it regulates host energy metabolism at cold temperatures have rarely been illustrated. In this study, we evaluated the status of glycolipid metabolism and oxidative stress in pigs based on the gut-liver axis and propose that AMP-activated protein kinase(AMPK) is a key target for alleviating energy stress at cold temperatures by dietary fat supplementation.Results Dietary fat supplementation alleviated the negative effects of cold temperatures on growth performance and digestive enzymes, while hormonal homeostasis was also restored. Moreover, cold temperature exposure increased glucose transport in the jejunum. In contrast, we observed abnormalities in lipid metabolism, which was characterized by the accumulation of bile acids in the ileum and plasma. In addition, the results of the ileal metabolomic analysis were consistent with the energy metabolism measurements in the jejunum, and dietary fat supplementation increased the activity of the mitochondrial respiratory chain and lipid metabolism. As the central nexus of energy metabolism, the state of glycolipid metabolism and oxidative stress in the liver are inconsistent with that in the small intestine. Specifically, we found that cold temperature exposure increased glucose transport in the liver, which fully validates the idea that hormones can act on the liver to regulate glucose output. Additionally, dietary fat supplementation inhibited glucose transport and glycolysis, but increased gluconeogenesis, bile acid cycling, and lipid metabolism. Sustained activation of AMPK, which an energy receptor and regulator, leads to oxidative stress and apoptosis in the liver;dietary fat supplementation alleviates energy stress by reducing AMPK phosphorylation.Conclusions Cold stress reduced the growth performance and aggravated glycolipid metabolism disorders and oxidative stress damage in pigs. Dietary fat supplementation improved growth performance and alleviated cold temperature-induced energy stress through AMPK-mediated mitochondrial homeostasis. In this study, we high-light the importance of AMPK in dietary fat supplementation-mediated alleviation of host energy stress in response to environmental changes.

A Dynamic Multi-ary Query Tree Protocol for Passive RFID Anti-collision

In this paper,a dynamic multi-ary query tree(DMQT)anti-collision protocol for Radio Frequency Identification(RFID)systems is proposed for large scale passive RFID tag identification.The proposed DMQT protocol is based on an iterative process between the reader and tags which identifies the position of collision bits through map commands and dynamically encodes them to optimize slots allocation through query commands.In this way,the DMQT completely eliminates empty slots and greatly reduces collision slots,which in turn reduces the identification time and energy costs.In addition and differently to other known protocols,the DMQT does not need to estimate the number of tags,reducing the protocol implementation complexity and eliminating the uncertainty caused by the estimation algorithm.A numerical analysis shows that DMQT has better performance than other algorithms for a number of tags larger than 300.Meanwhile,when the number of tags is 2000 and the tag identity(ID)length is 128 bits,the total identification time is 2.58 s and the average energy cost for a tag identification is 1.2 mJ,which are 16.9%and 10.4%less than those of state-of-the-art algorithms,respectively.In addition,a DMQT extension based on ACK command has also been presented to deal with capture effect and avoid missing identification.

A flexible Hf_(0.5)Zr_(0.5)O_(2) thin film with highly robust ferroelectricity

Flexible hafnia-based ferroelectric memories are arousing much interest with the ever-growing demands for nonvolatile data storage in wearable electronic devices.Here,high-quality flexible Hf_(0.5)Zr_(0.5)O_(2)membranes with robust ferroelectricity were fabricated on inorganic pliable mica substrates via an atomic layer deposition technique.The flexible Hf_(0.5)Zr_(0.5)O_(2) thin membranes with a thickness of∼8 nm exhibit a high remanent polarization of∼16μC/cm^(2),which possess very robust polarization switching endurance(>10^(10) cycles,two orders of magnitude better than reported flexible HfO_(2)-based films)and superior retention ability(expected>10 years).In particular,stable ferroelectric polarization as well as excellent endurance and retention performance show negligible degradations under 6 mm radius bending conditions or after 10^(4) bending cycles with a 6 mm bending radius.These results mark a crucial step in the development of flexible hafnium oxide-based ferroelectric memories for wearable electronic devices.

Glucose supplementation improves intestinal amino acid transport and muscle amino acid pool in pigs during chronic cold exposure

Mammals in northern regions chronically suffer from low temperatures during autumn-winter seasons.The aim of this study was to investigate the response of intestinal amino acid transport and the amino acid pool in muscle to chronic cold exposure via Min pig models(cold adaptation)and Yorkshire pig models(non-cold adaptation).Furthermore,this study explored the beneficial effects of glucose supplementation on small intestinal amino acid transport and amino acid pool in muscle of cold-exposed Yorkshire pigs.Min pigs(Exp.1)and Yorkshire pigs(Exp.2)were divided into a control group(17℃,n=6)and chronic cold exposure group(7℃,n=6),respectively.Twelve Yorkshire pigs(Exp.3)were divided into a cold control group and cold glucose supplementation group(8℃).The results showed that chronic cold exposure inhibited peptide transporter protein 1(PepT1)and excitatory amino acid transporter 3(EAAT3)expression in ileal mucosa and cationic amino acid transporter-1(CAT-1)in the jejunal mucosa of Yorkshire pigs(P<0.05).In contrast,CAT-1,PepT1 and EAAT3 expression was enhanced in the duodenal mucosa of Min pigs(P<0.05).Branched amino acids(BCAA)in the muscle of Yorkshire pigs were consumed by chronic cold exposure,accompanied by increased muscle RING-finger protein-1(MuRF1)and muscle atrophy F-box(atrogin-1)expression(P<0.05).More importantly,reduced concentrations of dystrophin were detected in the muscle of Yorkshire pigs(P<0.05).However,glycine concentration in the muscle of Min pigs was raised(P<0.05).In the absence of interaction between chronic cold exposure and glucose supplementation,glucose supplementation improved CAT-1 expression in the jejunal mucosa and PepT1 expression in the ileal mucosa of cold-exposed Yorkshire pigs(P<0.05).It also improved BCAA and inhibited MuRF1 and atrogin-1 expression in muscle(P<0.05).Moreover,dystrophin concentration was improved by glucose supplementation(P<0.05).In summary,chronic cold exposure inhibits amino acid absorption in the small intestine,depletes BCAA and promotes protein degradation in muscle.Glucose supplementation ameliorates the negative effects of chronic cold exposure on amino acid transport and the amino acid pool in muscle.

Dispersion–tribological property relationship in mineral oils containing 2D layered α-zirconium phosphate nanoplatelets

Inorganic nanomaterials exhibit superior friction-reduction and anti-wear properties in oils. In this study, 2D layered α-zirconium phosphate (α-ZrP) nanosheets intercalated with different amines have been synthesized to study their dispersion stabilities in lubricating oil and tribological applications. The intercalated amines should be sufficiently long and lipophilic to provide stabilization to α-ZrP nanosheets in mineral oil. The results of tribological tests illustrate that with the addition of well-dispersed nanosheets, the coefficient of friction (COF) and pin volume loss reduce by ~47% and 75%, respectively. The excellent dispersion stability enables the nanosheets to flow into the contact area at the beginning, and thereby protect the rubbing surface. A reduction in the van der Waals forces between the adjacent layers induced by the intercalated amines transforms the friction between adjacent layers from pin disk to sliding, leading to a decrease in the COF under hydrodynamic lubrication. The study provides a new method to enhance the tribological properties via tuning the dispersion stabilities of nanomaterials in oils.

A flexible BiFeO_(3)-based ferroelectric tunnel junction memristor for neuromorphic computing

Ferroelectric tunnel junctions(FTJs)as the artificial synaptic devices have been considered promising for constructing brain-inspired neuromorphic computing systems.However,the memristive synapses based on the flexible FTJs have been rarely studied.Here,we report a flexible FTJ memristor grown on a mica substrate,which consists of an ultrathin ferroelectric barrier of BiFeO_(3),a semiconducting layer of ZnO,and an electrode of SrRuO_(3).The obtained flexible FTJ memristor exhibits stable voltage-tuned multistates,and the resistive switchings are robust after 10^(3) bending cycles.The capability of the FTJ as a flexible synaptic device is demonstrated by the functionality of the spike-timing-dependent plasticity with bending,and the accurate conductance manipulation with small nonlinearity(-0.24)and low cycle-to-cycle variation(1.77%)is also realized.Especially,artificial neural network simulations based on experimental device behaviors reveal that the high recognition accuracies up to 92.8%and 86.2%are obtained for handwritten digits and images,respectively,which are close to the performances for ideal memristors.This work highlights the potential applications of FTJ as flexible electronics for data storage and processing.

Continuous and fast magneto-ionic control of magnetism in Ta/Co/ BiFeO_(3)/SrRuO_(3) multiferroic heterostructure

Room temperature electric field controlled magnetism is extremely promising for the next-generation high-performance spintronic devices.Here,based on the ferroelectric switching driven oxygen ion migration in the Ta/Co/BiFeO_(3)/SrRuO_(3) heterostructures,the magnetic moment,magnetic coercive field,exchange bias field,and junction resistance are reversibly manipulated by tuning the ferroelectric polarization of the BiFeO_(3) layer.All these phenomena are consistently explained by the oxygen ion migration induced CoOx/Co redox effect,which is evidenced by the synchrotron X-ray absorption spectroscopy measurements.Interestingly,owing to the controllable ferroelectric switching dynamics of the BiFeO_(3) thin film,the magnetic coercive field of the Co thin film can be continuously and precisely tuned by controlling the ferroelectric polarization of the BiFeO_(3) thin film,and the manipulating speed of the voltage control of magnetism can be fast to 100 ns.This nonvolatile,stable,reversible,fast,and reproducible voltage control of magnetism shows great potential for designing low-power and high-speed spintronics.

Improved energy storage performance of nanocomposites with Bi_(4.2)K_(0.8)Fe_(2)O_(9+δ) nanobelts

Modern electronics and electric power grids require high performance polymer-based dielectric nanocomposites.To realize large-scale applications,the energy density of nanocomposites needs to be further increased.Here,we demonstrate a remarkable improvement in energy density of poly(vinylidene fluoride)(PVDF)matrix upon the incorporation of high-k Bi_(4.2)K_(0.8)Fe_(2)O_(9+δ)(BKFO)nanobelts.High aspect ratio BKFO nanobelts can enhance the Young's moduli of the nanocomposites and increase the path tortuosity of electrical trees,which are favorable for increasing the breakdown strength of the system.Thus,the dielectric constant and breakdown strength increase simultaneously at a low volume fraction(0.35 vol%)of BKFO nanobelts,and an ultrahigh recoverable energy density of 25.4 J/cm^(3) is achieved.These results provide a strategy to develop high performance flexible high-energy-density devices.