Online systemic energy management strategy of fuel cell system with efficiency enhancement

Temperature plays a crucial role in efficiency improvement and lifespan extension of the fuel cell system which encourages energy management strategy (EMS) taking thermal into consideration. However, sluggish thermal response prevents the fuel cell performance from tracking the optimal states during scenarios with significant power variations, which was disregarded in the previous works. To solve this issue, an online hydrogen consumption minimization guarantee strategy (HCMG) including thermal management is proposed which is divided into two parts: 1) primary power distribution strategy, where a model predictive control (MPC) based EMS is employed herein to distribute power between fuel cell and battery with the objectives of minimizing hydrogen consumption as well as maintaining the state of charge (SOC), and 2) HCMG, where a modified MPC based method is exploited herein to track the reference power and optimal temperature with minimum hydrogen consumption by adjusting both the duty cycle of fan and fuel cell current. The presented approach ascertains hydrogen consumption reduction for 3.448% even under relatively extensive power changes, during which the temperature cannot reach the optimal value in a brief time. The real-time simulation results show the effectiveness of the proposed technique compared with previous EMS methods under various driving cycles

Research Progress on the molecular mechanism of the Utilization of Human Milk Oligosaccharides in Bifidobacterium longum subsp. infantis and Its probiotic effect

Human milk is the most important source of nutrition in early infancy, which can meet all the nutritional needs in the first 6 months after birth. It contains many bioactive substances that can regulate the intestinal flora, promote the development of the immune system, and enhance the intestinal barrier. Human milk oligosaccharides (HMOs) are one of the active substances in human milk. They cannot be directly digested and absorbed by infants, but can be used as a prebiotic to stimulate the establishment and evolution of the gut microbiota. Bifidobacterium longum subsp. infantis is a dominant microorganism in the gut of breastfed infants, which has almost all gene clusters required for metabolizing the major HMOs, and its interaction with HMOs plays a key role in the early intestinal health of infants. This review summarizes the composition and structure of HMOs, describes the utilization of HMOs by B. longum subsp. infantis and summarizes the beneficial effects B. longum subsp. infantis exerts in infants by metabolizing HMOs, which will lay the foundation for exploring the interaction mechanism between HMOs and the gut microbiota, as well as its role in infant intestinal development and maturation

Growth of carbon nanostructures on carbonized electrospun nanofibers with palladium nanoparticles

This paper studies the mechanism of the formation of carbon nanostructures on carbon nanofibers with Pd nanoparticles by using different carbon sources. The carbon nanofibers with Pd nanoparticles were produced by carbonizing electrospun polyacrylonitrile (PAN) nanofibers including Pd(Ac)2. Such PAN-based carbon nanofibers were then used as substrates to grow hierarchical carbon nanostructures. Toluene, pyridine and chlorobenzine were employed as carbon sources for the carbon nanostructures. With the Pd nanoparticles embedded in the carbonized PAN nanofibers acting as catalysts, molecules of toluene, pyridine or chlorobenzine were decomposed into carbon species which were dissolved into the Pd nanoparticles and consequently grew into straight carbon nanotubes, Y-shaped carbon nanotubes or carbon nano-ribbons on the carbon nanofiber substrates. X-ray diffraction analysis and transmission electron microscopy (TEM) were utilized to capture the mechanism of formation of Pd nanoparticles, regular carbon nanotubes, Y-shaped carbon nanotubes and carbon nano-ribbons. It was observed that the Y-shaped carbon nanotubes and carbon nano-ribbons were formed on carbonized PAN nanofibers containing Pd-nanoparticle catalyst, and the carbon sources played a crucial role in the formation of different hierarchical carbon nanostructures

Large-Scale Cloning and Comparative Analysis of TaNAC Genes in Response to Stripe Rust and Powdery Mildew in Wheat (Triticum aestivum L.)

The NAM, ATAF1/2, and CUC2 (NAC) transcription factors (TFs) constitute the largest plant-specific TF superfamily, and play important roles in various physiological processes, including stress responses. Stripe rust and powdery mildew are the most damaging of the fungal diseases that afflict wheat (Triticum aestivum L.). However, studies on Triticum aestivum NAC (TaNAC)s’ role in resistance to the two diseases are still limited, especially in an overall comparative analysis of TaNACs responding or not to fungal stress. In the present study, 186 TaNAC transcripts were obtained from the resistant hexaploid wheat line N9134 under fungal stress, and 180 new transcripts were submitted to GenBank. Statistical results show that 35.1% (54/154) of TaNAC genes responded to stripe rust and powdery mildew in the seedling stage. “Abnormal” coding transcripts of differentially expressed (DE)-TaNAC genes in wheat responding to fungal stress were found in a significantly higher proportion (24/117 vs. 8/69, p = 0.0098) than in non-DE-NACs. This hinted that the alternative splicing of TaNAC genes was active in transcriptional or post-transcriptional regulation during plant-pathogen interactions. Full-length NAC proteins were classified into nine groups via phylogenetic analysis. Multiple-sequence alignment revealed diversity in the C-terminal structural organization, but the differentially expressed gene (DEG)-encoding proteins enriched in Subgroups VI and VII were conserved, with WV[L/V]CR amino acid residues in Motif 7 following the NAM domain. Our data that showed TaNAC TFs responded to fungal disease, which was affected by expression levels and by the regulation of multifarious transcript variants. These data for TaNAC responses to stripe rust and/or powdery mildew and their numerous structural variants provide a good resource for NAC function–mechanism analysis in the context of biotic-stress tolerance in wheat

Towards intelligent and integrated architecture for hydrogen fuel cell system: challenges and approaches

The hydrogen fuel cell is rapidly attracting research interest for its potential in power generation and electrified transportation. The fuel cell stack (FCS) is a complex system comprising multiple coupled subsystems, and in order to maximize the utilization of an FCS, the system-level design and control can be optimized through modeling, data-based analytics and monitoring. To this end, a systematic overview of the system architecture and control of hydrogen fuel cells is provided in this review, with focus on integration and intelligence. Firstly, the fuel cell subsystems, namely the cathode, anode and cooling loops are reviewed, where their respective control methods and impact on FCS performance are discussed. DC/DC converters are another core component of FCS, and we present an overview of fuel cell DC/DC converter topologies and integrated control of DC/DC converter and air compressor. Finally, the system-level integration of fuel cells in power systems is surveyed. In the conclusions, we discuss the challenges and perspectives concerning the integrated architecture and intelligent control for FCS, including cohesive dynamic models, data-based approaches, and integrated hardware architecture

Adipose-derived stem cells ameliorate radiation-induced lung injury by activating the DDAH1/ADMA/eNOS signaling pathway

Background: Ionizing radiation-induced lung injury is caused by the initial inflammatory reaction and leads to advanced fibrosis of lung tissue. Adipose-derived stem cells (ASCs) are a type of mesenchymal stem cell that can differentiate into various functional cell types with broad application prospects in the treatment of tissue damage. The purpose of this study was to explore the protective effect of ASCs against radiation-induced lung injury and to provide a novel basis for prevention and treatment of radiation-induced lung injury. Materials and methods: Fifty mice were randomly divided into a control group (Ctrl), radiation exposure group (IR), radiation exposure plus ASC treatment group (IR + ASC), radiation exposure plus L-257 group (IR + L-257), and radiation exposure plus ASC treatment and L-257 group (IR + ASC + L-257). Mice in IR, IR + ASC, and IR + ASC + L-257 groups were exposed to a single whole-body dose of 5 Gy X-rays (160 kV/25 mA, 1.25 Gy/min). Within 2 h after irradiation, mice in IR + ASC and IR + ASC + L-257 groups were injected with 5 × 106 ASCs via the tail vein. Mice in IR + L-257 and IR + ASC + L-257 groups were intraperitoneally injected with 30 mg/kg L-257 in 0.5 mL saline. Results: The mice in the IR group exhibited lung hemorrhage, edema, pulmonary fibrosis, and inflammatory cell infiltration, increased release of proinflammatory cytokines, elevation of oxidative stress and apoptosis, and inhibition of the dimethylarginine dimethylamino hydratase 1 (DDAH1)/ADMA/eNOS signaling pathway. ASC treatment alleviated radiation-induced oxidative stress, apoptosis, and inflammation, and restored the DDAH1/ADMA/eNOS signaling pathway. However, L-257 pretreatment offset the protective effect of ASCs against lung inflammation, oxidative stress, and apoptosis. Conclusions: These data suggest that ASCs ameliorate radiation-induced lung injury, and the mechanism may be mediated through the DDAH1/ADMA/eNOS signaling pathway

A Sensitive Pyrimethanil Sensor Based on Electrospun TiC/C Film

Titanium carbide (TiC) is a very significant transition metal carbide that displays excellent stability and electrical conductivity. The electrocatalytic activity of TiC is similar to noble metals but is much less expensive. Herein, carbon nanofibers (CNFs)-supported TiC nanoparticles (NPs) film (TiC/C) is prepared by electrospinning and carbothermal processes. Well-dispersed TiC NPs are embedded tightly into the CNFs frameworks. The electrochemical oxidation of pyrimethanil (PMT) at the TiC/C-modified electrode displays enhanced redox properties, and the electrode surface is controlled simultaneously both by diffusion and adsorption processes. When TiC/C is applied for PMT determination, the as-fabricated sensor shows good sensing performance, displaying a wide linear range (0.1–600 μM, R2 = 0.998), low detection limit (33 nM, S/N = 3), and good reproducibility with satisfied anti-interference ability. In addition, TiC/C shows long-term stability and good application in natural samples. The facile synthetic method with good sensing performance makes TiC/C promising as novel electrode materials to fabricate efficient sensors

Towards intelligent and integrated architecture for hydrogen fuel cell system: challenges and approaches

The hydrogen fuel cell is rapidly attracting research interest for its potential in power generation and electrified transportation. The fuel cell stack (FCS) is a complex system comprising multiple coupled subsystems, and in order to maximize the utilization of an FCS, the system-level design and control can be optimized through modeling, data-based analytics and monitoring. To this end, a systematic overview of the system architecture and control of hydrogen fuel cells is provided in this review, with focus on integration and intelligence. Firstly, the fuel cell subsystems, namely the cathode, anode and cooling loops are reviewed, where their respective control methods and impact on FCS performance are discussed. DC/DC converters are another core component of FCS, and we present an overview of fuel cell DC/DC converter topologies and integrated control of DC/DC converter and air compressor. Finally, the system-level integration of fuel cells in power systems is surveyed. In the conclusions, we discuss the challenges and perspectives concerning the integrated architecture and intelligent control for FCS, including cohesive dynamic models, data-based approaches, and integrated hardware architecture

Structural Characterization and Functional Analysis of Mevalonate Kinase from <i>Tribolium castaneum</i> (Red Flour Beetle)

Mevalonate kinase (MevK) is an important enzyme in the mevalonate pathway that catalyzes the phosphorylation of mevalonate into phosphomevalonate and is involved in juvenile hormone biosynthesis. Herein, we present a structure model of MevK from the red flour beetle Tribolium castaneum (TcMevK), which adopts a compact α/β conformation that can be divided into two parts: an N-terminal domain and a C-terminal domain. A narrow, deep cavity accommodating the substrate and cofactor was observed at the junction between the two domains of TcMevK. Computational simulation combined with site-directed mutagenesis and biochemical analyses allowed us to define the binding mode of TcMevK to cofactors and substrates. Moreover, TcMevK showed optimal enzyme activity at pH 8.0 and an optimal temperature of 40 °C for mevalonate as the substrate. The expression profiles and RNA interference of TcMevK indicated its critical role in controlling juvenile hormone biosynthesis, as well as its participation in the production of other terpenoids in T. castaneum. These findings improve our understanding of the structural and biochemical features of insect Mevk and provide a structural basis for the design of MevK inhibitors

Pd_<i>x</i>Co_<i>y</i> Nanoparticle/Carbon Nanofiber Composites with Enhanced Electrocatalytic Properties

Novel bimetallic Pd_<i>x</i>Co_<i>y</i> alloy nanoparticle (NP)/carbon nanofiber (CNF) composites with superior electrocatalytic performances were successfully prepared by electrospinning Pd and Co precursors, i.e., Pd­(acac)₂ and Co­(acac)₂, in polyacrylonitrile followed by a thermal treatment. Uniform dispersion of Pd_<i>x</i>Co_<i>y</i> nanoparticles in carbon nanofibers was achieved. Chemical composition and size of the resulting Pd_<i>x</i>Co_<i>y</i> NPs, which showed a substantial effect on the electrocatalytic properties of Pd_<i>x</i>Co_<i>y</i>/CNF nanocomposites, can be readily controlled by adjusting the feed ratio of metal precursors. In comparison with commercial Pd/C and other state-of-the-art Pd- or Pt-based catalysts, Pd_<i>x</i>Co_<i>y</i>/CNF nanocomposites prepared in this study exhibited much higher electrocatalytic activity and stability in formic acid and methanol oxidation reactions. This improved electrocatalytic performance is very attractive for fuel cell applications and can be attributed to the unique bimetallic Pd–Co alloy formation, a modified electronic structure of Pd in Pd_<i>x</i>Co_<i>y</i>, as well as uniform dispersion and firm embedment of Pd_<i>x</i>Co_<i>y</i> NPs in CNF