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Distributed energy resources (DERs) and microgrids have seen tremendous growth and research activities in recent years. Flexible DERs and asynchronous microgrids (ASMG) can have many system-level benefits over fixed DERs and conventional microgrids. The key enabler for flexible DERs and ASMG is a power converter based power conditioning system (PCS) as the interface between DERs/microgrids and the medium voltage (MV) distribution grid. High voltage (HV, >3.3 kV) silicon carbide (SiC) based MV converter is now a promising solution for the PCS. This article presents development and testing of a 10 kV SiC MOSFET based MV PCS for 13.8 kV ASMG. MV PCS converter design addressing high dv/dt issue generated by fast switching of the 10 kV SiC MOSFET is presented. The developed PCS is successfully tested at 25 kV dc 13.8 kV ac voltages and 100 kVA power. Grid support functions are also demonstrated with the developed PCS prototype and hardware tests beds, validating HV SiC converter benefits for ASMG. Published version This work was supported by the U.S. Department of Energy (DOE) PowerAmerica at North Carolina State University. This work made use of the Engineering Research Center Shared Facilities supported by the Engineering Research Center Program of the NSF and DOE under NSF award number EEC-1041877 and the CURENT Industry Partnership Program.

Tetranychus urticae Koch is a worldwide pest mite which can cause continuous damage to multiple plants even in hot environment such as greenhouse due to its strong endurance to high temperature. In order to clarify the physiological mechanisms of T. urticae in response to short-term heat stress, four high temperatures (36, 39, 42, and 45°C), three short-term heat durations (2, 4, and 6 h) were conducted to test the effects on the protein content of T. urticae and the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and total antioxidant capacity (T-AOC), respectively. The results showed that protein content, antioxidant enzymes activity, and T-AOC in T. urticae were significantly affected by both the high temperature and duration after treatment, meanwhile, they showed same trends of increased at 25–39℃, then decreased at 39–42℃ except for CAT activity. The highest values of SOD activity, POD activity and T-AOC were all obtained at 39℃-4h, and that of CAT activity was obtained at 39℃-2h. The higher levels of T-AOC serve an important signal demonstrating that T. urticae has other antioxidant mechanisms except for antioxidant enzymes. Those results suggested that heat stress induces oxidative stress, and antioxidant enzymes played important role in reducing oxidative damage in T. urticae. which provided a basis for further research on the molecular mechanisms of thermostability and ecological adaptability of T. urticae.

This paper focuses on the dynamic tracking control of ammunition manipulator system. A standard state space model for the ammunition manipulator electro-hydraulic system (AMEHS) with inherent nonlinearities and uncertainties considered was established. To simultaneously suppress the violation of tracking error constraints and the complexity of differential explosion, a barrier Lyapunov functions-based dynamic surface control (BLF-DSC) method was proposed for the position tracking control of the ammunition manipulator. Theoretical analysis prove the stability of the closed-loop overall system and the tracking error converges to a prescribed neighborhood asymptotically. The effectiveness and dynamic tracking performance of the proposed control strategy is validated via simulation and experimental results.

The strong adhesion of thermally conductive silicone encapsulants on highly integrated electronic devices can avoid external damages and lead to an improved long-term reliability, which is critical for their commercial application. However, due to their low surface energy and chemical reactivity, the self-adhesive ability of silicone encapsulants to substrates need to be explored further. Here, we developed epoxy and alkoxy groups-bifunctionalized tetramethylcyclotetrasiloxane (D4H-MSEP) and boron-modified polydimethylsiloxane (PDMS-B), which were synthesized and utilized as synergistic adhesion promoters to provide two-component addition-cured liquid silicone rubber (LSR) with a good self-adhesion ability for applications in electronic packaging at moderate temperatures. The chemical structures of D4H-MSEP and PDMS-B were characterized by Fourier transform infrared spectroscopy. The mass percentage of PDMS-B to D4H-MSEP, the adhesion promoters content and the curing temperature on the adhesion strength of LSR towards substrates were systematically investigated. In detail, the LSR with 2.0 wt% D4H-MSEP and 0.6 wt% PDMS-B exhibited a lap-shear strength of 1.12 MPa towards Al plates when curing at 80 °C, and the cohesive failure was also observed. The LSR presented a thermal conductivity of 1.59 W m−1 K−1 and good fluidity, which provided a sufficient heat dissipation ability and fluidity for potting applications with 85.7 wt% loading of spherical α-Al2O3. Importantly, 85 °C and 85% relative humidity durability testing demonstrated LSR with a good encapsulation capacity in long-term processes. This strategy endows LSR with a good self-adhesive ability at moderate temperatures, making it a promising material requiring long-term reliability in the encapsulation of temperature-sensitive electronic devices.

Firms compete intensely in sponsored search. Their bidding strategies hinge on understanding who competes with whom, how they compete, and how consumers react to competing advertisements. In this context, we investigate how firm competition impacts consumers’ click-through behaviors in search advertising from a strategic group perspective. Using search results from Google and consumers’ clickstream data, we found strong negative externality for competitors within the same strategic group relative to competitors across strategic groups: firms reap fewer click-throughs when an advertisement of another firm from the same strategic group is also displayed in search results, relative to when other displayed advertisers are not from the same group. This indicates that when competitors from the same strategic group are likely to appear in the results of a sponsored search auction, the focal firm would be better off avoiding head-to-head competition in the auction. However, we did not find empirical evidence of such firm behaviors, suggesting myopia or the inability of firms to avoid such competition. We also show that when multiple firms from the same strategic group appear in search results, the closer the focal firm is located to such competing firms, the more click-throughs the firm accrues. This suggests that firms should stay close to their within-group competitors when they compete in the same search auction. Further, our empirical results indicate that firms are indeed doing so. Using another set of data from Google AdWords reports, we show that our findings are also robust to multi-keyword bidding scenarios. These findings represent the first attempt to understand the impact of strategic groups in search advertising and provide interesting implications for advertisers and search engines.

Aflatoxins in moldy peanuts are seriously toxic to humans. These kernels need to be screened in the production process. Hyperspectral imaging techniques can be used to identify moldy peanuts. However, the changes in spectral information and texture information caused by the difference in moisture content in peanuts will affect the identification accuracy. To reduce and eliminate the influence of this factor, a data augmentation method based on interpolation was proposed to improve the generalization ability and robustness of the model. Firstly, the near-infrared hyperspectral images of 5 varieties, 4 classes, and 3 moisture content gradients with 39,119 kernels were collected. Then, the data augmentation method called the difference of spectral mean (DSM) was constructed. K-nearest neighbors (KNN), support vector machines (SVM), and MobileViT-xs models were used to verify the effectiveness of the data augmentation method on data with two gradients and three gradients. The experimental results show that the data augmentation can effectively reduce the influence of the difference in moisture content on the model identification accuracy. The DSM method has the highest accuracy improvement in 5 varieties of peanut datasets. In particular, the accuracy of KNN, SVM, and MobileViT-xs using the data of two gradients was improved by 3.55%, 4.42%, and 5.9%, respectively. Furthermore, this study provides a new method for improving the identification accuracy of moldy peanuts and also provides a reference basis for the screening of related foods such as corn, orange, and mango.

A polydimethylsiloxane armed with epoxy, alkoxy and acrylate groups was synthesized from silanol terminated-PDMS and epoxy and acrylate groups functionalized silane coupling agents, and utilized as the adhesion promoter (AP) to prepare addition-cured liquid silicone rubber that exhibited self-adhesion ability (SA-LSR) with biocompatible thermoplastic polyurethanes (TPU) sheets. The structural characteristics of AP were characterized by Fourier transform infrared (FTIR) spectroscopy, which demonstrated the strong adhesion to polyester-based TPU sheets due to a sufficient amount of acrylate groups, epoxy groups and silanol groups obtained by the hydrolysis of alkoxy groups. In detail, the peel-off strength of SA-LSR and TPU joints reached up to 7.63 N mm−1 after the optimization of adhesion promoter including type and content, and curing condition including time and temperature. The cohesive failure was achieved during the sample breakage process. Moreover, the SA-LSR showed a good storage stability under proper storage conditions. This design strategy provided the feasibility to combine the advantages of addition-cured liquid silicone rubber and plastics with low melting points, promoting the potential application range of those silicone-based materials.

To the Editor Opioid therapy is the first-line pharmacological approach for moderate-to-severe pain after surgery, but the potential overprescribing of opioids after surgery may contribute to opioid-related adverse events.[1][1] Given the lack of clinical evidence regarding the consumption patterns

An asynchronous microgrid (ASMG) with silicon carbide (SiC) MOSFET-based power conditioning system (PCS) is an attractive option for future microgrids, which can potentially improve microgrid dynamic performance and grid power quality. To support future microgrids’ needs for higher power, scaling PCS power via paralleling multiple modules or converters is a potential solution. In this paper, a strategy for scalable ASMG PCS operation is proposed. MMC-based PCSs are implemented to demonstrate the proposed strategy, including MMC paralleling operation analysis and corresponding control functions. Experimental results are provided to demonstrate the scalable PCS operation at 25 kV rated voltage.

Medium voltage (MV) asynchronous microgrids have numerous unique benefits over regular synchronous MV ac microgrids. This paper focuses on a MV transformer less asynchronous microgrids power conditioning system (PCS) using 10 kV SiC MOSFETs. The benefits of a 10 kV SiC MOSFET based PCS include simplified topology, higher control bandwidth, and hence more advanced control functions, although it is still challenging to apply 10 kV SiC MOSFETs with their associated much faster switching speed in MV systems. A modular design approach is adopted in the design and implementation of the PCS as well as its controller. The sophisticated grid functions of the asynchronous microgrid PCS are supported by a hierarchical modular control system. A 100 kVA back-to-back transformer less PCS for a 13.8 kV MV grid is developed and tested at rated voltage and power.

Asynchronous microgrid (ASMG) is a microgrid concept where the ac microgrid is connected to a utility grid through a power conditioning system (PCS). The development of high voltage (HV, >3.3 kV) silicon carbide (SiC) MOSFET technology promotes the implementation of ASMG PCS converters. However, the system-level benefits from SiC MOSFETs have not been well studied for this application. This paper discusses ASMG system stability enhancement resulting from HV SiC MOSFET-based PCS converters. HV SiC MOSFET-based PCS converters can achieve high control frequency, which can benefit the potential harmonic instability caused by the digital control delay. A detailed theoretical analysis is provided, and experimental results for the stability enhancement capability are demonstrated on a converter-based hardware testbed (HTB).

This paper provides an analysis of the desat protection for high voltage (>3.3 kV) SiC MOSFETs from the perspective of noise immunity. The high positive dv/dt with long voltage rise time generated by high voltage SiC MOSFETs is identified as a major threat to noise immunity of the desat protection circuitry. The impact of numerous influencing factors is analyzed, such as parasitic inductance, damping resistance, and clamping impedance. In some cases, small parasitic capacitances (

A supra-amphiphilic polymer (SAP) with controlled molecular structures is constructed, in this work, via self-complementary hydrogen bonding of guanosine groups between a hydrophilic block, poly(N-isopropylacrylamide), and a hydrophobic block, poly(ε-caprolactone). By simply changing the mixing ratio of the guanosine-capped hydrophilic and hydrophobic blocks, a series of SAPs with tailored nanostructures are constructed, which can further self-assemble into different nano-aggregates in solution, including spheres, vesicles and large vesicle micelles. The thermo-induced phase transition of the hydrophilic block induces the fusion and aggregation of the nanoparticles into irregular particles upon heating, which further transform to large compound vesicles after cooling.

A novel block copolymer is fabricated by orthogonally coupling two end-functionalized polymers, glucose-capped methoxypoly(ethylene glycol) (mPEG2k-diol) and phenylboronic acid-capped poly(e-caprolactone) (PBA-PCL), with dual boronate ester and B N/B O dynamic covalent interactions. Due to their synergetic effect, this block copolymer can self-assemble into micelles in aqueous solution with high stability. More importantly, micellar disassembly can be only triggered in the presence of both signal inputs, acid and salt, displaying an “AND” logic-gate responsive behavior.

To investigate whether dendritic superstructures can be formed from random copolymers, the morphological evolution of a random copolymer, poly(p-dioxanone-co-butylene-co-succinate) (PPBS), is tracked at different crystallization temperatures by optical microscopy. The crystal morphology is regulated by controlling the molecular structure of PPBS as well as the crystallization temperatures, that is, from rounded spherulite for the homopolymer counterpart to dendrites for the copolymer with high p-dioxanone (PDO) content and crystallization temperature. Different from previous works on dendritic crystals, interestingly, film thickness shows no obvious effect on the formation of dendrites. While we find that the crystal growth rate is seriously frustrated by the random structures of PPBS copolyester. Besides, small-angle X-ray scattering (SAXS) analysis indicated that the inter-lamellar region of PPBS copolyester is highly affected by the crystallization temperature. The PDO content, random structure, and high crystallization temperature were believed to be the main factors for the crystals transition from well-rounded spherulite to dendritic crystals.

HCHO removal from indoor air was usually slow and inefficient due to the low concentration but persistent release, inadequate oxidation and less efficient catalysts at room temperature. PEC (photo-electro-catalysis) can better remove pollutant than PC (photocatalysis) or EC (electro-catalysis), but was rarely used directly in indoor air purification, because often aqueous electrolyte was not considered in indoor air purification reactor. Theoretically, removing HCHO in indoor air by PEC is possible, the question is how to integrate gas phase reaction with electric field and electrolyte. In this article, using copper anode in a thin film liquid electrolyte and high activity Pt/TiO2-ZnO cathode, efficient HCHO removal was realized by photo-electro-catalytic oxidation. The nano catalyst was prepared by sol-gel method and loaded on stainless steel mesh as cathode. Its structure, morphology and photocatalytic properties were characterized. The effect of Pt loading and/or external resistances on the removal efficiencies were investigated. Within 120 min of reaction time, 74% HCHO (0.16 mg/m3, in 5.56 10−3 m3 air volume) was removed using 36 cm2 cathode loaded with 4.16 10−3 mg/cm2 catalyst, while only 42% and 53% was removed respectively in PC and EC using the same catalyst and reactor.

Objective: To study effect of joint distraction osteogenesis combined with platelet-rich plasma injections on traumatic ankle arthritis (TAA). Methods: 106 patients with TAA admitted to our hospital (from January 2018 to January 2020) were recruited as the study cohort and randomly divided into a surgical group and a combined group. The surgical group was treated with simple joint retraction surgery, and the combined group was treated with platelet-rich plasma injections in addition to the surgery administered to the operation group. After 6 months of treatment, the clinical efficacy of the two groups was evaluated, and the changes in the ankle joint function, the serum related factors, and the quality of life before and at six months after the treatment were observed. The incidences of adverse reactions (ARS) in the two groups were counted to evaluate the treatment safety. Results: The total effective rate was 98.11% in the combined group and 77.36% in the operation group. The overall curative effect of the combined group was better than it was in the operation group (P0.05). Conclusion: Arthroplasty with platelet-rich plasma injections can improve joint function recovery, inhibit the inflammatory factor expression levels, and enhance TAA patients’ quality of life.

Background: Two published meta-analyses have investigated the effects of the number of injections of platelet rich plasma (PRP) on clinical outcomes in knee osteoarthritis patients, however conflicting findings were generated. Methods: We will systematically search PubMed, Embase, and China National Knowledgement Infrastructure (CNKI) to capture additional eligible studies. After screening citations, extracting essential data, assessing the risk of bias, we will use RevMan software and Open BUGS to perform head-to-head and network meta-analysis of pain alleviation and improvement of joint functionality, respectively. Discussion: Knee joint osteoarthritis (KOA) is the main cause of joint degeneration in elderly, which seriously reduces patients quality of life. Although intra-articular PRP has been extensively prescribed to treat KOA, a definitive conclusion about the appropriate number of injections has not yet been generated in published meta-analyses. The present updated network meta-analysis will comprehensively answer this question. Ethics and dissemination: We will communicate our findings through participating in academic conferences or submiting it to be considered for publication in peer reviewed scholar journal. INPLASY registration number: We registered this protocol in International Plateform of Registered Systematic Review and Meta-Analysis Protocols (INPLASY) platform and obtained an identifier of INPLASY2020110043 (https://inplasy.com/inplasy-2020-11-0043/).

The behavior of 10 kV SiC MOSFETs during a flashover fault condition is investigated comprehensively. A larger turn-off gate resistance R g,off is recommended for 10 kV SiC MOSFETs without Kelvin source to avoid very asymmetrical gate resistance, while a small R g,off is recommended for 10 kV SiC MOSFETs with Kelvin source. Guidelines regarding gate loop inductance and selecting an external capacitor across gate and source terminal are also provided. 10 kV SiC MOSFETs have much higher energy loss under flashover fault compared to typical short circuit faults. The required response time for short circuit protection to safely clear flashover fault should be at least 350 ns shorter than the response time designed to clear conventional short circuit faults.

Asynchronous microgrid with power condition system (PCS) converter is a potential future application area of medium voltage converters. However, there has been only limited research focusing on actual implementation of PCS converters. This paper describes the controller development of a 13.8 kV, silicon carbide (SiC) MOSFET-based dc/ac four-wire modular multi-level converter (MMC) for an asynchronous microgrid considering grid requirements. Control architecture and detailed central and phase controller functions are discussed. Experimental results under balanced and unbalanced load conditions are demonstrated.

A test scheme is designed to qualify MMC submodules based on 10 kV SiC MOSFETs comprehensively, including thermal design, insulation design, and operation under high dv/dt. In the test scheme, the essential step is the continuous test realized with the proposed ac-dc continuous test circuit with two MMC submodules in series. With the designed modulation scheme, two cascaded submodules are leveraged to generate high dv/dt. The submodule under test has to continuously withstand 2X normal dv/dt of 10 kV SiC MOSFETs, which could occur during the MMC converter operation. Higher dv/dt can also be generated to fully test the submodule. An open loop voltage balancing method is adopted to simplify the continuous test setup. Simulation and experimental results are provided to validate the proposed test scheme.

Suffering weak mechanical properties, hydrogels are generally limited for high load-bearing applications. Herein, chitosan and poly(acrylic acid) (PAA) are employed as double networks (DN), and metal-coordination and chain entanglement are exploited as dual crosslinks to develop fully physically crosslinked DN hydrogels. In spite of the non-covalent crosslinking, the hydrogel exhibits impressive tensile properties (3.7 ± 0.12 MPa) and toughness (1200 ± 50% of elongation at break and 2.8 × 103 J m−2 of fracture energy). In addition, good fatigue resistance and self-recovery performance are achieved for the hydrogel because of their supramolecular nature. Notably, the DN hydrogel display good self-healing property with recovered fracture stress and strain of 1.4 MPa and ∼700%, respectively. The results indicate that the supramolecular design proposed in this work can bring more benefits for wide applications of hydrogel.

To increase power rating, parallel-connected converters are widely used in power systems. However, it brings challenge to output harmonic current control. For active power filter, the harmonic current compensation performance worsens. A virtual resistor has significant effect on the amplitude and phase of the output current. Based on the analysis of current control loop with a virtual resistor, an enhanced current control method is proposed. The optimal value of a virtual resistor is used to stabilize the amplitude of the output harmonic current. The phase control of a filter capacitor harmonic voltage is used to regulate the phase of the output harmonic current. Finally, simulation and experimental results verify the correctness of theoretical analysis and effectiveness of the method. Load harmonic current compensation capability is guaranteed.

Recently, charge transfer (CT) interactions have received attention for the fabrication of supramolecular architectures due to their inherent compatibilities, directional nature and solvent tolerance. In this study, we report a shape-memory dynamic network constructed by the CT interaction between π-electron-rich naphthalene embedded in poly(ethylene glycol) (PEG-Np) and π-electron-poor six-arm methyl-viologen-ended poly(ethylene glycol) (6PEG-MV), which was verified by ultraviolet–visible spectroscopy (UV–vis), fluorescence spectra and swelling tests. Interestingly, the mechanical properties of this CT complex were dramatically enhanced compared with the control without CT interaction. Moreover, the excellent shape-memory effect (SME) was realized due to the good crystallization of the PEG segment and stable netpoints based on the CT interaction. In addition, as we expected, this supramolecular polymer network is self-healable and reprocessable.

Microbe-mediated soil nitrification and denitrification processes affect the variations in soil N2O fluxes. Researchers are concerned about how the abundances of nitrifiers and denitrifiers and the N2O fluxes from temperate semi-arid grassland soil vary as nitrogen (N) and water inputs vary. In this study, we report the results from a field experiment that was set up in a temperate semi-arid grassland area in northern China in May 2017. In August 2018, we collected samples to investigate how a range of physical, chemical and biological characteristics of soil, including the pH, moisture, dissolved organic carbon content (DOC) and available N content, N2O fluxes, and the abundances of ammonia oxidizers and denitrifiers in the soil, changed after N (4 g N·m−2·year−1 NH4NO3) and water (112.5 mm·year−1) were added over a period of 1 year. We analyzed the abundances of AOA amoA, AOB amoA, nirS, nirK and nosZ using quantitative PCR. We found that the soil N2O emissions were negatively affected by the water additions, but were not affected by the N additions. We also found that the AOA amoA and nosZ genes responded positively to the N additions. Watering had a positive effect on the nirS gene abundance, while N additions and water together intensified the effect of only water on the nirS gene abundance. The nirS gene abundance, soil pH, and DOC content explained 46.1%, 20.1% and 12.0% of the variations in the soil N2O fluxes, respectively. These results provide improved insights into how microorganisms affect N cycling, and may be used to help predict how soil N2O fluxes might change in the future, as N deposition and precipitation change.

In this work, we present a mild one-step enzymatic-catalyzed copolymerization of diethyl succinate, 1,4-butanediol and p-dioxanone (PDO) to synthesize poly(p-dioxanone-co-butylene-co-succinate) copolyesters. Their chemical structure, triad distributions, and molecular weight of the copolyesters are characterized by 1H NMR, 13C NMR and GPC. All copolyesters have narrow molecular weight polydispersity (1.3–1.5) and higher molecular weight (Mw) values (23700–33200 g mol−1), which are well controlled by varying the amount of PDO units from 9 to 30 mol%. NMR, DSC, and XRD results show that copolyesters are semicrystalline random copolyesters and thermal properties depended on their composition. Furthermore, the degradation rate of the poly(p-dioxanone-co-butylene-co-succinate) are enhanced compared to PBS.

The repetitive control (RC) strategy is widely used in AC power systems because of its high performance in tracking period signal and suppressing steady-state error. However, the dynamic response of RC is determined by the fundamental period delay T 0 existing in the internal model. In the current study, a (nk ± i)-order harmonic RC structure is proposed to improve dynamic performance. The proposed structure has less data memory and can improve the tracking speed by n/2 times. T 0 proves the effectiveness of the (nk ± i)-order RC strategy. The simulation and experiments of (6k ± 1)-order and (4k ± 1)-order RC strategy used in the voltage source inverter is conducted in this study to control the harmonic current source, which shows the validity and advantages of the proposed structure.

This paper presents a small-signal modeling method for modular multilevel converter (MMC) based on harmonic state-space (HSS) method. This modeling method could achieve high accuracy since it considers both dynamics and interactions of the internal harmonics (sub-module capacitor voltage ripples and arm circulating currents). Then eigenvalue analysis is applied to estimate the stability of MMC based on the presented model. Finally, the small-signal model is validated by comparing the step response with the simulation built in Simulink /MATLAB. And the influence of controller parameters on system stability is illustrated, which would improve the efficiency of system control designing.

To observe the effect of microRNA-155 (miR-155) on the inflammatory response of rat alveolar macrophages induced by lipopolysaccharide (LPS).The alveolar macrophages NR8383 of rat were cultured in vitro, the macrophages in logarithmic growth phase were harvested to conduct experiment. (1) The 1 mg/L LPS was used to stimulate the rat alveolar macrophages for 3, 6, 12, and 24 hours, a phosphate buffer solution (PBS) control group was also set up. Enzyme linked immunosorbent assay (ELISA) was used to detect the dynamic changes of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in the supernatant, and real-time quantitative reverse transcription-polymerase chain reaction (RT-qPCR) was used to detect the dynamics expression of miR-155 in the cells, which confirmed the optimal time for LPS stimulation was 12 hours. (2) Carboxyfluorescein (FAM) labeled mimic (FAM mimic) and inhibitor (FAM inhibitor) were used to transfect the alveolar macrophage, and the transfection effect was observed under inverted fluorescence microscope 6 hours later to confirm the optimal transfection concentration of mimic was 20 nmol/L, and the optimal transfection concentration of inhibitor was 100 nmol/L. miR-155 mimic and miR-155 inhibitor were transfected to alveolar macrophages respectively at the optimal transfection concentration for 24 hours, and 1 mg/L LPS was used to stimulate the cells for 12 hours. A mimic negative control + LPS group and an inhibitor negative control + LPS group were set up. The expressions of IL-1β and TNF-α in the supernatant were determined by ELISA to observe the regulation of miR-155 on inflammatory response of alveolar macrophages.(1) After stimulation of 1 mg/L LPS on alveolar macrophages, the contents of IL-1β and TNF-α in the supernatant and the expression of miR-155 in the cells were increased gradually with time prolongation, IL-1β and TNF-α contents peaked at 12 hours, and the expression of miR-155 peaked at 24 hours [as compared with PBS control group, IL-1β (ng/L): 910.43±36.09 vs. 22.66±7.84, TNF-α (ng/L): 3 138.39±394.10 vs. 233.92±8.84, miR-155 (2In LPS induced inflammatory response of alveolar macrophages, miR-155 plays an obvious inhibitory role.

An adaptive sliding mode control approach is proposed for the precision control of the electro-hydraulic position servo system of the elevation-balancing machine of artillery platform. Adaptive algorithm is used to estimate uncertain parameters of the system and a simple discontinuous projection mapping is applied to ensure the boundedness of the uncertain estimated parameters, which can reduce the influence of parameter uncertainties. Switching functions is regulated by adaptive algorithm and the chattering problem is avoided. Simulation results show that adaptive sliding mode control algorithm tracks the desired trajectory rapidly with reasonable accuracy and steady-state errors.

Miktoarm star copolymers, which are in the simplest form of branching, are particularly of interest to biomedical applications. Nevertheless, their synthesis is facing troubles of seeking inner cores with heterogeneous functional groups as well as tedious protection and deprotection. Herein, ethyl-β- d -glucopyranoside, a sugar molecule containing homogeneous groups, was directly employed as a core to synthesize an amphiphilic miktoarm star copolymer via a chemoenzymatic approach without complicated decoration and protection of the core. Because of the high regioselectivity originated from enzymatic catalysis, the resultant copolymers with well-regulated molecular architecture were synthesized, which can self-assemble into highly-stable nanoaggregates in aqueous media. The copolymers were nontoxic in preliminary in vitro cytotoxicity assays and able to carry doxorubicin into tumor cells, indicating their promising application as a new biocompatible platform for drug delivery.

Background As one of the important management practices of grassland ecosystems, grazing has fundamental effects on soil properties, vegetation, and soil microbes. Grazing can thus alter soil respiration (Rs) and the soil carbon cycle, yet its impacts and mechanisms remain unclear. Methods To explore the response of soil carbon flux and temperature sensitivity to different grazing systems, Rs, soil temperature (ST), and soil moisture (SM) were observed from December 2014 to September 2015 in a typical steppe of Inner Mongolia under three grazing systems: year-long grazing, rest-rotation grazing, and grazing exclusion. In addition, plant aboveground and root biomass, soil microbial biomass and community composition, and soil nutrients were measured during the pilot period. Results Soil respiration was significantly different among the three grazing systems. The average Rs was highest under rest-rotation grazing (1.26 μmol·m−2·s−1), followed by grazing exclusion (0.98 μmol·m−2·s−1) and year-long grazing (0.94 μmol·m−2·s−1). Rs was closely associated with ST, SM, potential substrate and root, and soil microbe activity. The effects of grazing among two grazing systems had generality, but were different due to grazing intensity. The root biomass was stimulated by grazing, and the rest-rotation grazing system resulted in the highest Rs. Grazing led to decreases in aboveground and microbial biomass as well as the loss of soil total nitrogen and total phosphorus from the steppe ecosystem, which explained the negative effect of grazing on Rs in the year-long grazing system compared to the grazing exclusion system. The temperature sensitivity of Rs (Q10) was higher in the rest-rotation and year-long grazing systems, likely due to the higher temperature sensitivity of rhizosphere respiration and higher “rhizosphere priming effect” in the promoted root biomass. The structural equation model analysis showed that while grazing inhibited Rs by reducing soil aeration porosity, ground biomass and SM, it increased Q10 but had a lower effect than other factors. A better understanding of the effects of grazing on soil respiration has important practical implications.

Due to the profound impact of nitrogen (N) input on soil systems, linking the activity and composition of soil microbial communities to soil organic carbon (SOC) is crucial to reveal the microbial-driven mechanisms underlying SOC decomposition by nitrogen fertilization. A long-term nitrogen fertilization experiment with 6 urea fertilizer gradients (0, 2, 4, 8, 16, and 32 g N m−2 yr−1) was conducted on a temperate grassland. The soil basic characteristics, microbial community DNA sequences, five soil enzymes including C, N, and phosphorus cycling, and soil C fractions were measured after 14 years of N addition. N fertilization significantly modified both the bacterial and fungal community composition, with larger variations at higher N levels. N fertilization increased the proportion of copiotrophic bacteria and saprotrophic fungi. Specific enzyme activities standardized by microbial biomass carbon among N fertilizing gradients demonstrated that the potential of labile C acquisition was stable, but the potential of N and P acquisition and recalcitrant C degradation were increased. Recalcitrant soil C fractions including alkyl C and aromatic C significantly differed among N levels, despite the stable SOC concentration. The variations of bacterial phyla and fungal trophic guilds were both associated with specific enzyme activities; meanwhile, fungal phyla were more related to soil C fractions, as the Basidiomycota abundance echoed the proportion of aromatic C at 4–16 g N m−2 yr−1. In conclusion, this study indicates that the changes in microbial community composition by N fertilization can have far-reaching impacts on SOC turnover and nutrient acquisition.

Inverter with output LCL filter is widely used in power system. It has better switching frequency harmonic suppression effect, meanwhile it has resonance problem. Virtual resistor damping can suppress the resonance, but it affects the current control character, particularly for harmonic current. This paper develops the detailed models of the inverter with virtual resistor damping for output harmonic current control. Based on the analysis of current control loop with virtual resistor, the transfer function of current loop is obtained. Moreover, with the optimal value of virtual resistor, the performance of inverter is similar to 2nd order low pass filter. To control the output current equals to reference current, reference regulation method is proposed. At last, simulation and experimental results verify the correctness of theatrical analysis and effectiveness of the method.

Although microRNA-132 (miR-132) has been shown to be involved in the inflammatory regulation, its role in sepsis-induced lung injury is unknown. We hypothesized that miR-132 attenuated lipopolysaccharide (LPS)-induced inflammation of alveolar macrophages by targeting acetylcholinesterase (AChE) and enhancing the acetylcholine (ACh)-mediated cholinergic anti-inflammatory response.The LPS-treated rat alveolar macrophage cell line NR8383 was used as the inflammatory model. To assess the effect of miR-132, alveolar macrophages were transfected with miR-132 mimic or inhibitor.We found that miR-132 was upregulated in LPS-stimulated alveolar macrophages. Induction of AChE mRNA showed an inverse pattern with respect to AChE protein and activity, suggesting posttranscriptional regulation of AChE. Utilizing miR-132 mimic transfection, we found that overexpression of miR-132 enhanced the ACh-mediated cholinergic anti-inflammatory reaction by targeting AChE mRNA in LPS-treated alveolar macrophages. Blockage of miR-132 using miR-132 inhibitor reversed the Ach action upon LPS-induced release of inflammatory mediators and reduction in AchE protein/activity. Moreover, in the presence of ACh, upregulation of miR-132 suppressed LPS-induced nuclear translocation of NF-κB and production of STAT3 and phosphorylated STAT3, while downregulation of miR-132 enhanced the nuclear translocation of NF-κB.We propose that miR-132 functions as a negative regulator of the inflammatory response in alveolar macrophages by potentiating the cholinergic anti-inflammatory pathway, and represents a potential therapeutic leverage point in modulating inflammatory responses.