In order to identify the effects of drought stress on protective enzyme activity and physiological properties, four mulberry varieties, i.e.,＇Nanye- 1＇, ＇Yunsang- 1＇, ＇Xinyizhilai＇ and ＇Husang-32＇ in the Panxi...In order to identify the effects of drought stress on protective enzyme activity and physiological properties, four mulberry varieties, i.e.,＇Nanye- 1＇, ＇Yunsang- 1＇, ＇Xinyizhilai＇ and ＇Husang-32＇ in the Panxi Region of Sichuan Province, China, were selected. The activity of superoxide dismutase （SOD）, peroxidase （POD） and catalase （CAT） in four mulberry varieties was determined. Soluble protein, soluble sugar, proline, net photosynthetic rate and transpiration rate of mulberry leaves were analyzed. The results show that during the early stages of drought stress, protective enzyme activities in four mulberry varieties continually increased. However, prolonged and intensified drought stress decreased their activities. After re-watering, they gradually returned to normal levels. Under drought stress and after re-watering, ＇Nanye-l＇ and ＇Yunsang-l＇ clearly showed smaller changes in soluble protein content than the ＇Xinyizhilai＇ and ＇Husang-32＇ varieties, whereas changes in their soluble sugar content were clearly greater than these last two varieties. When water deficit was protracted and intensified, ＇Nanye-1＇ and ＇Yunsang-1＇ still showed higher net photosynthetic, transpiration rates and water-use efficiency than ＇Xinyizhilai＇ and ＇Husang-32＇.展开更多
AIM： To investigate the possible mechanism of the protective effects of a bioactive fraction, Ganoderma lucidum proteoglycan （GLPG）isolated from Ganoderma luddum mycelia, against carbon tetrachloride-induced liver ...AIM： To investigate the possible mechanism of the protective effects of a bioactive fraction, Ganoderma lucidum proteoglycan （GLPG）isolated from Ganoderma luddum mycelia, against carbon tetrachloride-induced liver injury. METHODS： A liver injury model was induced by carbon tetrachloride. Cytotoxicity was measured by MTY assay. The activities of alanine aminotransferase （ALT） and aspartate aminotransferase （AST） were determined with an automatic multifunction-biochemical analyzer and the levels of superoxide dismutase （SOD） and TNF-α were determined following the instructions of SOD kit and TNF radioimmunoassay kit. Uver sections were stained with hematoxylin and eosin （H＆E） for histological evaluation and examined under light microscope. RESULTS： We found that GLPG can alleviate the L-02 liver cells injury induced by carbon tetrachloride （CCh） through the measurements of ALT and AST activities and the administration of GLPG to L-02 cells did not display any toxicity. Furthermore, histological analysis of mice liver injury induced by CCh with or without GLPG pretreatment indicated that GLPG can significantly suppress the toxicity induced by CCh in mice liver. We also found that GLPG reduced TNF-α level induced by CCh in the plasma of mice, whereas increased SOD activity in the rat serum. CONCLUSION： GLPG has hepatic protective activity against CCl4 induced injury both in vitro and in vivo. The possible antihepatotoxic mechanisms may be related to the suppression of TNF-α level and the free radical scavenging activity.展开更多
A systematic study was conducted to determine the effects of water stress on the activities of protective enzymes and lipid peroxidation in maize. The results showed that, under water stress, the activities of superox...A systematic study was conducted to determine the effects of water stress on the activities of protective enzymes and lipid peroxidation in maize. The results showed that, under water stress, the activities of superoxide dismutase （SOD）, catalase （CAT）, and peroxidase （POD） in leaves and roots increased sharply at prophase and metaphase growth stages, such as, male tetrad stage, but then declined towards the physiological maturity. The protective enzyme activities in roots were lower than those in leaves. The content of malondialdehyde （MDA） increased according to the severity of water stress. The content of MDA in roots was lower than that in leaves. The activities of protective enzymes and lipid peroxidation in roots were positively related to that in leaves with most of the correlation coefficients being significant. The content of soluble proteins in roots and leaves decreased with increasing drought stress. The ear characteristics deteriorated and the economic yields of maize decreased significantly under water stress. The main factors that caused reduction of yields were the decrease in the number of ear kernels and 100-kernel weight.展开更多
Two phenolic acids P-hydroxy benzoic acid and cinnamic acid were designated as four concentrations (0, 50 μmol/L, 100 μmol/L, 150 μmol/L) to investigate the effects of phenoic acids on the growth and the activities...Two phenolic acids P-hydroxy benzoic acid and cinnamic acid were designated as four concentrations (0, 50 μmol/L, 100 μmol/L, 150 μmol/L) to investigate the effects of phenoic acids on the growth and the activities of membrane protective enzymes of cucumber seedlings. The results showed that both phenolic acids inhibited the seedlings growth. The inhibitory effects were increased with the concentration of phenolic acids increasing and the time of treatment prolonging. Seedlings treated with A150 (P-hydroxy benzoic acid, 150 μmol/L), B50 (cinnamic acid, 50 μmol/L), B100 (cinnamic acid, 100 μmol/L), B150 (cinnamic acid, 150 μmol/L) showed significantly shorter in plant height , smaller in leaf area. and lighter in fresh weight. The inhibitory effect of cinnamic acid was comparatively stronger than that of P-hydroxy benzoic acid. For protective enzymes system, compared to control , the POD activity increased at all concentrations of P-hydroxy benzoic acid during the treatment but increased at first then decreased before increased again at last at all concentrations of cinnamic acid .In the case of CAT, its activity increased at first, then decreased, and increased again at lower concentrations of phenolic acids. However, at higher concentrations the activities decreased at first, then increased a little, decreased continuously at last. In addition, the treatments of phenolic acids led to an increase then a decreaseof SOD activity and an increase of MDA content in the seedlings. All above indicated the accumulating of free radicalsand destruction of protective enzymes at higher concentrations of phenolic acids.展开更多
Two-dimensional materials have been proved to be effective in improving the performance of anticorrosive coatings.However,most of the reported two-dimensional materials only have the ability to passively block corrosi...Two-dimensional materials have been proved to be effective in improving the performance of anticorrosive coatings.However,most of the reported two-dimensional materials only have the ability to passively block corrosive media and cannot effectively inhibit localized corrosion reactions at the metal/coating interface.Herein,we first synthesized a novel polyaniline(PANI)nanosheet with both barrier and passivation functions for metals.In addition,polydopamine(PDA)wrapped PANI nanosheets(PANI@PDA)were obtained by in situ self-polymerization reaction of dopamine on the PANI surface,which enhance its interfacial interaction with polymeric resin.The chemical structure,morphology and corrosion inhibition properties of the nanosheets were systematically analyzed.The incorporated PANI@PDA nanosheets in composite coating provide a longer penetration path for corrosive mediums.Secondly,the uniformly dispersed two-dimensional nanosheets induce the formation of passivation film on the metal substrate.The protective effect of PANI@PDA nanosheets on coatings was verified by electrochemical impedance spectroscopy(EIS).Results indicated that the prepared composite coating exhibited excellent corrosion resistance throughout the test cycle.This simple and effective modification strategy based on conductive polymers provides a new insight into the development of environmentally adaptive composite coatings with active and passive protection.展开更多
An active protection coating for pH-responsive was prepared.The hollow mesoporous silica microspheres(HMSNs)were loaded with 2-mercaptobenzothiazole(MBT),and then they were coated with chitosan(CS).The composite micro...An active protection coating for pH-responsive was prepared.The hollow mesoporous silica microspheres(HMSNs)were loaded with 2-mercaptobenzothiazole(MBT),and then they were coated with chitosan(CS).The composite microspheres were in the range of 650−750 nm in diameter.CS-HMSN-MBT coating had a faster repair rate under acidic conditions by synergistic effect between CS and MBT.The repair rate under alkaline conditions was slowed down.The active protection performance reached the strongest after 3 d immersion.The corrosion inhibitor release mechanism was optimized to extend the service life of the coating and to achieve long-term service of the copper substrate.展开更多
[Objective] The pattern of leaves senescence was studied to provide reference for the planting technology and breeding rice cultivars resistant to premature senescence. [Method] Six hybrid rice cultivars were cultivat...[Objective] The pattern of leaves senescence was studied to provide reference for the planting technology and breeding rice cultivars resistant to premature senescence. [Method] Six hybrid rice cultivars were cultivated under limited and conventional irrigation managements; after the heading of rice, the root activities, nitrogen content in leaves, chlorophyll content （SPAD value）, net photosynthetic rate and the activities of superoxide dismutase （SOD）, peroxidase （POD）, catalase （CAT） were determined. [Result] The rhythms in attenuation of xylem sap flow rate, leaf nitrogen content, chlorophyll content （SPAD value） and net photosynthetic rate of different rice cultivars were significantly different in attenuation starting time, attenuation frequency and attenuation range. Physiological indexes of different cultivars responded inconsistently to water shortage. Extremely significantly positive correlations were found between the decline rates of chlorophyll content and leaf nitrogen content and xylem sap flow rate of roots, the photosynthetic rate and chlorophyll content. The changes in activities of SOD, CAT and POD were different, and responded to water shortage differently in different cultivars. The change dynamic of leaf nitrogen content and chlorophyll content was positively related with the activity dynamic of SOD and CAT. The change dynamic of leaf nitrogen content and chlorophyll content was negatively related with the malondialdehyde （MDA） content. The difference in the attenuation rhythm of physiological indexes of leaves and response to water shortage of different hybrid rice cultivars were related to genotype difference. Increasing roots activities and protecting enzyme activities of leaves benefit to defer attenuation of chlorophyll content and nitrogen content of leaves and to keep stronger photosynthetic function. [Conclusion] The senescence resistance of rice is a combined result of genotype differences and physiological response to environment.展开更多
Firefighting protective clothing is a crucial protective equipment for firefighters to minimize skin burn and ensure safety firefighting operation and rescue mission.A recent increasing concern is to develop self-powe...Firefighting protective clothing is a crucial protective equipment for firefighters to minimize skin burn and ensure safety firefighting operation and rescue mission.A recent increasing concern is to develop self-powered fire warning materials that can be incorporated into the firefighting clothing to achieve active fire protection for firefighters before the protective clothing catches fire on fireground.However,it is still a challenge to facilely design and manufacture thermoelectric(TE)textile(TET)-based fire warning electronics with dynamic surface conformability and breathability.Here,we develop an alternate coaxial wet-spinning strategy to continuously produce alternating p/n-type TE aerogel fibers involving n-type Ti_(3)C_(2)T_(x)MXene and p-type MXene/SWCNT-COOH as core materials,and tough aramid nanofiber as protective shell,which simultaneously ensure the flexibility and high-efficiency TE power generation.With such alternating p/n-type TE fibers,TET-based self-powered fire warning sensors with high mechanical stability and wearability are successfully fabricated through stitching the alternating p-n segment TE fibers into aramid fabric.The results indicate that TET-based fire warning electronics containing 50 p-n pairs produce the open-circuit voltage of 7.5 mV with a power density of 119.79 nW cm-2 at a temperature difference of 300℃.The output voltage signal is then calculated as corresponding surface temperature of firefighting clothing based on a linear relationship between TE voltage and temperature.The fire alarm response time and flame-retardant properties are further displayed.Such self-powered fire warning electronics are true textiles that offer breathability and compatibility with body movement,demonstrating their potential application in firefighting clothing.展开更多
The development of smart coatings with potential for active anticorrosion and self-healing protection of metals is essential for long-term performance of metallic structures in aggressive chemical environments.Present...The development of smart coatings with potential for active anticorrosion and self-healing protection of metals is essential for long-term performance of metallic structures in aggressive chemical environments.Presently,emphasis has been placed on the development of advanced smart coatings for corrosion protection in different applications.Innovative multifunctional coatings with fascinating stimuliresponsive functionalities are considered“smart”.The stimuli-responsive functionalities of these smart coatings when properly harnessed result in a class of coatings with inherent autonomous control of corrosion.Fundamentally,when metals are exposed to aggressive environments,occurrences at the metalsolution interface cause environmental changes.These changes can be controlled when triggers from external environment set off active components of smart coating,thereby enhancing coating’s life and functionality.Common triggers include the availability of moisture,concentration of chloride ion,p H gradient,mechanical damage,impact,fatigue,light,redox activity and temperature.In this review,recent technological trends in active anticorrosion and self-healing coatings as functional routes for metal protection are summarized,stimuli responsiveness and mechanisms of inhibition are discussed,and recent multi-action protective systems are particularly focused on.展开更多
Zinc aluminium(Zn-Al)and lithium aluminium(Li-Al)–layered double hydroxides(LDH)coatings with incorporated inhibitors(Li-,Mo-and W-based)were successfully synthesized on AZ31 Mg alloy.Zn-Al LDH W and Li-Al LDH Li sho...Zinc aluminium(Zn-Al)and lithium aluminium(Li-Al)–layered double hydroxides(LDH)coatings with incorporated inhibitors(Li-,Mo-and W-based)were successfully synthesized on AZ31 Mg alloy.Zn-Al LDH W and Li-Al LDH Li showed the highest corrosion resistance and were selected for further evaluation.SEM cross-section examination revealed a bi-layer structure composed of an outer part with loose flakes and a denser inner layer.XRD,FTIR,and XPS analysis confirmed the incorporation of the inhibitors.Post-treatments with corrosion inhibitors containing solutions resulted in the selective dissolution of the most external layer of the LDH coating,reducing the surface roughness,hydrophilicity and paint adhesion of the layers.Active corrosion properties were confirmed by SVET evaluation for the Zn-Al LDH W coating.The proposed active corrosion mechanism involves the ion-exchange of aggressive Cl-ions,deposition of hydroxides and competitive adsorption of W-rich corrosion inhibitors.展开更多
In recent decades,the potential health hazards of microwave exposure have been attracting increasing attention.Our previous studies have demonstrated that microwave exposure impaired learning and memory in experimenta...In recent decades,the potential health hazards of microwave exposure have been attracting increasing attention.Our previous studies have demonstrated that microwave exposure impaired learning and memory in experimental animal models[1,2].展开更多
In the present research, the strain SLYY-3 was isolated from sediments of Jiaozhou Bay, Qingdao, China. The strain SLYY- 3, which produced a bacteriocin-like substance （BLS）, was characterized to be a strain of Baci...In the present research, the strain SLYY-3 was isolated from sediments of Jiaozhou Bay, Qingdao, China. The strain SLYY- 3, which produced a bacteriocin-like substance （BLS）, was characterized to be a strain of Bacillus subtillis by biochemical profiling and 16S rDNA sequence analysis. It is the first time to report that Bacillus subtilis from Jiaozhou Bay sediments could produce a BLS. The BLS of B. subtillis SLYY-3 exhibited strong inhibitory activity against gram-positive bacteria （including Staphylococcus aureus and B. subtillis） and some fimgi （including Penicillium glaucum, Aspergillus niger and Aspergillus flavus）. The antimicrobial activity was detected from culture in the exponential growth phase and reached its maximum when culture entered into stationary growth phase. It was thermo-tolerant even when being kept at 100~C for 60 min without losing any activity and stable over a wide pH range from 1.0 to 12.0 while being inactivated by proteolytic enzyme and trypsin, indicating the proteinaceous nature of the BLS. The BLS was purified by precipitation with hydrochloric acid （HC1） and gel filteration （Sephadex G-100）. SDS-PAGE analysis of the extracellular peptides of SLYY-3 revealed a bacteriocin-like protein with a molecular mass of 66 kDa. Altogether, these characteristics indicate the potential of the BLS for food industry as a protection against pathogenic and spoilage microorganisms.展开更多
In order to effectively protect the activity of Epigallocatechin gallate（EGCG）, we explored the protection mechanism of Konjac glucomannan（KGM） for EGCG by experiments and theory analyses. We synthesized KGM/EGCG ...In order to effectively protect the activity of Epigallocatechin gallate（EGCG）, we explored the protection mechanism of Konjac glucomannan（KGM） for EGCG by experiments and theory analyses. We synthesized KGM/EGCG nanofibers by using electrostatic spinning method. The microstructure of nanofibers was characterized by SEM, FTIR, TGA, XRD and Raman spectroscopic. The formation mechanism and the protection effects of KGM/EGCG nanofibers were also discussed. The results showed that the EGCG activity was protected due to the hydrogen bonds between-OH of EGCG and KGM, and EGCG was embedded in KGM nanofiber with bead style. The reducing force and DPPH scavenging ability data indicated that KGM/EGCG nanofibers have stronger antioxidant activity than the EGCG solution under the same condition. Hence, the mosaic topological structure of KGM can effectively extend the EGCG activity.展开更多
γ-amidobutyric acid (GABA) is a major inhibitory neurotransmitter in the central nervous system and mediates fast synaptic inhibition through GABAA and GABAC
The neuron protective activity of the chemical constituents from Rheum nanum and Rheum sublanceolatum in vitro was investigated using cultured embryonic mouse cortical cells exposed to oxygen-glucose deprivation. The ...The neuron protective activity of the chemical constituents from Rheum nanum and Rheum sublanceolatum in vitro was investigated using cultured embryonic mouse cortical cells exposed to oxygen-glucose deprivation. The protective effect was quantitatively evaluated by measuring the lactate dehydrogenase release rate. Most of the compounds reduce the lactate dehydrogenase release rate, including emodin, chrysophanol-8-O-β-D-glucopyranoside, 6-hydroxymusizin-8-O-β-D-glucopyranoside, gnetin C, torachrysone-8-O-β-D-glucopyranoside, and maesopsin, and all possess potent neuron protective activity. Chrysophanol and aloe-emodin exhibit neuron protection only at low concentrations. Emodin-8-O-β-D-glucopyranoside protects the neuron cells at high concentration. Aloe-emodin-8-O-β-D- glucopyranoside is inactive.展开更多
Mechanical vibration defect is the key factor leading to sudden failure of gas-insulated switchgear(GIS)equipment.It is important to realise effective prediction of the me-chanical vibration state development trend of...Mechanical vibration defect is the key factor leading to sudden failure of gas-insulated switchgear(GIS)equipment.It is important to realise effective prediction of the me-chanical vibration state development trend of GIS equipment in order to improve its active safety protection level.This paper carried out research on the accurate prediction method and experimental validation of the mechanical vibration state and its defect severity development trend for the GIS equipment.Firstly,the deep and shallow vibration feature parameters for different mechanical defect signals were jointly extracted by time-domain features and deep belief network methods.Secondly,a new prediction model,incorporating the attention mechanism and the bidirectional gated recurrent unit(BiGRU),was constructed with the deep and shallow vibration feature parameters as inputs.Finally,the prediction trend effectiveness was verified based on the real-type GIS mechanical simulation platform and the field operation GIS equipment.Results show that the deep and shallow vibration feature extraction method proposed in this paper can characterise the mechanical defect information more comprehensively.The new prediction method of the vibration state trend based on the attention-BiGRU model shows ideal accuracy,and the predicted vibration state development trend is highly consistent with the actual,with an average absolute error of 0.063.The root mean square error(ERMSE)value of the prediction method is<5%,which reduces the relative error value at least 37% compared with the traditional prediction models.This paper provides a valuable reference for the proactive defence of GIS mechanical failure.展开更多
This work produced a Mg Al-layered double hydroxide by hydrothermal treatment of a plasma electrolytic oxidation(PEO)coating on magnesium alloy AZ31 in an phosphate electrolyte,followed by an ion-exchange reaction in ...This work produced a Mg Al-layered double hydroxide by hydrothermal treatment of a plasma electrolytic oxidation(PEO)coating on magnesium alloy AZ31 in an phosphate electrolyte,followed by an ion-exchange reaction in 0.1 M phosphate solution.The coated specimens were scratched.Characterization,including utilization of the localized technique SIET,measured the pH and p Mg distributions and optical morphologies around the artificial defects during immersion in 0.05 M NaCl solution.In contrast with phosphate loaded PEO/LDHs,a stronger alkalinization area(with pH 11.4~12.3)appeared in the passive PEO specimens.Due to formation of insoluble Mg(OH)_(2)products,the p Mg map showed depletion of Mg^(2+)in this high p H area.Combined with optical morphologies and SEM images,the better self-healing ability toward defects for phosphate loaded PEO/LDHs was confirmed.展开更多
Corrosion activities and related accidents are significant issues for marine facilities,leading to considerable economic losses.Waterborne epoxy(EP)coating has been seen as one of the optimal options for corrosion pro...Corrosion activities and related accidents are significant issues for marine facilities,leading to considerable economic losses.Waterborne epoxy(EP)coating has been seen as one of the optimal options for corrosion protection due to its stable properties and eco-friendliness(0 g/L volatile organic compounds).Nevertheless,several intrinsic deficiencies require improvement,such as fragile mechanical properties and defects(macro and micro),resulting in the continuous deterioration of comprehensive coating performances.In this work,a novel nanocomposite coating with mechanical enhancement,intelligent self-reporting,and active protection is fabricated by integrating the functionalized and compatible graphene oxide/cerium based metal-organic framework multiscale structure(GO-CeMOF-P/M).Notably,the homogenous dispersion of GO-CeMOF-P/M and its chemical interaction with the polymer matrix effectively reduces the defects resulting from solution volatilizing and enhances the compactness,which boosts the tensile strength(32.1 MPa/8.5%)and dry adhesion force(5.8 MPa)of the coating.Additionally,the controllable responsiveness and release of multiscale nanocomposite within external environments endow intelligent active protection and self-reporting characteristics for the GO-CeMOF-P/M-EP coating,making it especially suitable for a variety of practical marine applications.Furthermore,following immersion of 80 d in the aggressive environment,Zf=0.01 Hz value of GO-CeMOF-P/M-EP coating is 1.2×10^(10)Ωcm^(2),which is 164.4 times larger than that of EP coating(7.3×10^(7)Ωcm^(2)),demonstrating remarkably strengthened anti-corrosion ability.Consequently,by offering an intriguing design strategy,the current work anticipates addressing the inherent deficiencies of EP coating and facilitating its practicality and feasibility in real sea environments.展开更多
Model-based control shows promising potential for engine performance improve-ment and future aero-propulsion requirements.In this paper,an auto-updating thrust variation mitigation(AuTVM)control approach using on-boar...Model-based control shows promising potential for engine performance improve-ment and future aero-propulsion requirements.In this paper,an auto-updating thrust variation mitigation(AuTVM)control approach using on-board model strategies is proposed for gas tur-bine aero-engines under in-service degradation effects,which aims at active thrust regulation and acceleration protection in a simultaneous way.The AuTVM control is integrated with an on-line block,based on a reliable on-board engine model,and an off-line part for the periodical update of control parameters via post-flight engine monitoring data.The core feature of the AuTVM control is a set of auto-updating loops within the on-line part,including thrust regu-lation loop,surge margin loop,turbine entry temperature loop,and the steady loop,whose con-trol parameters are periodically adjusted with increasingflight cycles.Meanwhile,an industrial sensor-based baseline controller and two tailored model-based controllers,i.e.,a thrust variation mitigation(TVM)controller withfixed gains and a self-enhancing active transient protection(SeATP)controller with pro-active transient protection and passive thrust control,are also developed as comparison bases.Numerical simulations for idle to full-power acceleration tests are carried on a validated aero-thermal turbofan engine model using publicly available degra-dation data.Simulation results demonstrate that both new engines and severely degraded en-gines regulated by the AuTVM controller show significant thrust response enhancement,compared to the baseline controller.Moreover,thrust variation at the maximum steady state of degraded engines,which exists within the SeATP controller and the baseline controller,is suppressed by the proposed AuTVM controller.Robustness analysis against degradation uncer-tainties and sensor accuracy confirms that the AuTVM controller owns a closer maximum steady-state thrust distribution to the desired value than those of the SeATP and the baseline controller while utilizing transient margins of controlled engines more effectively.Hence,the control performance of the AuTVM controller for in-service engines is guaranteed.展开更多
基金supported by the Key Research Program of the Education Department of Sichuan Province (Nos. 2003A–032, 072A105)
文摘In order to identify the effects of drought stress on protective enzyme activity and physiological properties, four mulberry varieties, i.e.,＇Nanye- 1＇, ＇Yunsang- 1＇, ＇Xinyizhilai＇ and ＇Husang-32＇ in the Panxi Region of Sichuan Province, China, were selected. The activity of superoxide dismutase （SOD）, peroxidase （POD） and catalase （CAT） in four mulberry varieties was determined. Soluble protein, soluble sugar, proline, net photosynthetic rate and transpiration rate of mulberry leaves were analyzed. The results show that during the early stages of drought stress, protective enzyme activities in four mulberry varieties continually increased. However, prolonged and intensified drought stress decreased their activities. After re-watering, they gradually returned to normal levels. Under drought stress and after re-watering, ＇Nanye-l＇ and ＇Yunsang-l＇ clearly showed smaller changes in soluble protein content than the ＇Xinyizhilai＇ and ＇Husang-32＇ varieties, whereas changes in their soluble sugar content were clearly greater than these last two varieties. When water deficit was protracted and intensified, ＇Nanye-1＇ and ＇Yunsang-1＇ still showed higher net photosynthetic, transpiration rates and water-use efficiency than ＇Xinyizhilai＇ and ＇Husang-32＇.
基金Supported by a grant from the Institute of Virology, College of Life Sciences, Wuhan University
文摘AIM： To investigate the possible mechanism of the protective effects of a bioactive fraction, Ganoderma lucidum proteoglycan （GLPG）isolated from Ganoderma luddum mycelia, against carbon tetrachloride-induced liver injury. METHODS： A liver injury model was induced by carbon tetrachloride. Cytotoxicity was measured by MTY assay. The activities of alanine aminotransferase （ALT） and aspartate aminotransferase （AST） were determined with an automatic multifunction-biochemical analyzer and the levels of superoxide dismutase （SOD） and TNF-α were determined following the instructions of SOD kit and TNF radioimmunoassay kit. Uver sections were stained with hematoxylin and eosin （H＆E） for histological evaluation and examined under light microscope. RESULTS： We found that GLPG can alleviate the L-02 liver cells injury induced by carbon tetrachloride （CCh） through the measurements of ALT and AST activities and the administration of GLPG to L-02 cells did not display any toxicity. Furthermore, histological analysis of mice liver injury induced by CCh with or without GLPG pretreatment indicated that GLPG can significantly suppress the toxicity induced by CCh in mice liver. We also found that GLPG reduced TNF-α level induced by CCh in the plasma of mice, whereas increased SOD activity in the rat serum. CONCLUSION： GLPG has hepatic protective activity against CCl4 induced injury both in vitro and in vivo. The possible antihepatotoxic mechanisms may be related to the suppression of TNF-α level and the free radical scavenging activity.
文摘A systematic study was conducted to determine the effects of water stress on the activities of protective enzymes and lipid peroxidation in maize. The results showed that, under water stress, the activities of superoxide dismutase （SOD）, catalase （CAT）, and peroxidase （POD） in leaves and roots increased sharply at prophase and metaphase growth stages, such as, male tetrad stage, but then declined towards the physiological maturity. The protective enzyme activities in roots were lower than those in leaves. The content of malondialdehyde （MDA） increased according to the severity of water stress. The content of MDA in roots was lower than that in leaves. The activities of protective enzymes and lipid peroxidation in roots were positively related to that in leaves with most of the correlation coefficients being significant. The content of soluble proteins in roots and leaves decreased with increasing drought stress. The ear characteristics deteriorated and the economic yields of maize decreased significantly under water stress. The main factors that caused reduction of yields were the decrease in the number of ear kernels and 100-kernel weight.
文摘Two phenolic acids P-hydroxy benzoic acid and cinnamic acid were designated as four concentrations (0, 50 μmol/L, 100 μmol/L, 150 μmol/L) to investigate the effects of phenoic acids on the growth and the activities of membrane protective enzymes of cucumber seedlings. The results showed that both phenolic acids inhibited the seedlings growth. The inhibitory effects were increased with the concentration of phenolic acids increasing and the time of treatment prolonging. Seedlings treated with A150 (P-hydroxy benzoic acid, 150 μmol/L), B50 (cinnamic acid, 50 μmol/L), B100 (cinnamic acid, 100 μmol/L), B150 (cinnamic acid, 150 μmol/L) showed significantly shorter in plant height , smaller in leaf area. and lighter in fresh weight. The inhibitory effect of cinnamic acid was comparatively stronger than that of P-hydroxy benzoic acid. For protective enzymes system, compared to control , the POD activity increased at all concentrations of P-hydroxy benzoic acid during the treatment but increased at first then decreased before increased again at last at all concentrations of cinnamic acid .In the case of CAT, its activity increased at first, then decreased, and increased again at lower concentrations of phenolic acids. However, at higher concentrations the activities decreased at first, then increased a little, decreased continuously at last. In addition, the treatments of phenolic acids led to an increase then a decreaseof SOD activity and an increase of MDA content in the seedlings. All above indicated the accumulating of free radicalsand destruction of protective enzymes at higher concentrations of phenolic acids.
基金fundings from the National Natural Science Foundation of China(nos.51971121 and 52002228)the National Natural Science Foundation of China-Shandong Joint Fund for Marine Science Research Centers(CN)(No.U2106216)the Qingdao Marine Science and Technology Innovation Project(No.22-3-3-hygg-27-hy).
文摘Two-dimensional materials have been proved to be effective in improving the performance of anticorrosive coatings.However,most of the reported two-dimensional materials only have the ability to passively block corrosive media and cannot effectively inhibit localized corrosion reactions at the metal/coating interface.Herein,we first synthesized a novel polyaniline(PANI)nanosheet with both barrier and passivation functions for metals.In addition,polydopamine(PDA)wrapped PANI nanosheets(PANI@PDA)were obtained by in situ self-polymerization reaction of dopamine on the PANI surface,which enhance its interfacial interaction with polymeric resin.The chemical structure,morphology and corrosion inhibition properties of the nanosheets were systematically analyzed.The incorporated PANI@PDA nanosheets in composite coating provide a longer penetration path for corrosive mediums.Secondly,the uniformly dispersed two-dimensional nanosheets induce the formation of passivation film on the metal substrate.The protective effect of PANI@PDA nanosheets on coatings was verified by electrochemical impedance spectroscopy(EIS).Results indicated that the prepared composite coating exhibited excellent corrosion resistance throughout the test cycle.This simple and effective modification strategy based on conductive polymers provides a new insight into the development of environmentally adaptive composite coatings with active and passive protection.
基金Project(2023YFC2907304)supported by the National Key R&D Program Projects,ChinaProject(ZR2021ME087)supported by the Natural Science Foundation of Shandong Province,China+1 种基金Project(2022KLMM305)supported by the Shandong Provincial Key Laboratory of Mining Machinery Engineering School Enterprise Joint Fund,ChinaProject(2023CXPT062)supported by the Shandong Key Research and Development Program(Competitive Innovation Platform),China。
文摘An active protection coating for pH-responsive was prepared.The hollow mesoporous silica microspheres(HMSNs)were loaded with 2-mercaptobenzothiazole(MBT),and then they were coated with chitosan(CS).The composite microspheres were in the range of 650−750 nm in diameter.CS-HMSN-MBT coating had a faster repair rate under acidic conditions by synergistic effect between CS and MBT.The repair rate under alkaline conditions was slowed down.The active protection performance reached the strongest after 3 d immersion.The corrosion inhibitor release mechanism was optimized to extend the service life of the coating and to achieve long-term service of the copper substrate.
基金Supported by National Natural Science Foundation of China(30860137)the Fund from the Education Department of Jiangxi Province(GJJ09168)~~
文摘[Objective] The pattern of leaves senescence was studied to provide reference for the planting technology and breeding rice cultivars resistant to premature senescence. [Method] Six hybrid rice cultivars were cultivated under limited and conventional irrigation managements; after the heading of rice, the root activities, nitrogen content in leaves, chlorophyll content （SPAD value）, net photosynthetic rate and the activities of superoxide dismutase （SOD）, peroxidase （POD）, catalase （CAT） were determined. [Result] The rhythms in attenuation of xylem sap flow rate, leaf nitrogen content, chlorophyll content （SPAD value） and net photosynthetic rate of different rice cultivars were significantly different in attenuation starting time, attenuation frequency and attenuation range. Physiological indexes of different cultivars responded inconsistently to water shortage. Extremely significantly positive correlations were found between the decline rates of chlorophyll content and leaf nitrogen content and xylem sap flow rate of roots, the photosynthetic rate and chlorophyll content. The changes in activities of SOD, CAT and POD were different, and responded to water shortage differently in different cultivars. The change dynamic of leaf nitrogen content and chlorophyll content was positively related with the activity dynamic of SOD and CAT. The change dynamic of leaf nitrogen content and chlorophyll content was negatively related with the malondialdehyde （MDA） content. The difference in the attenuation rhythm of physiological indexes of leaves and response to water shortage of different hybrid rice cultivars were related to genotype difference. Increasing roots activities and protecting enzyme activities of leaves benefit to defer attenuation of chlorophyll content and nitrogen content of leaves and to keep stronger photosynthetic function. [Conclusion] The senescence resistance of rice is a combined result of genotype differences and physiological response to environment.
基金This work was financially supported by the Opening Project of National Local Joint Laboratory for Advanced Textile Processing and Clean Production(FX2022006)Guiding Project of Natural Science Foundation of Hubei province(2022CFC072)+2 种基金Guiding Project of Scientific Research Plan of Education Department of Hubei Province(B2022081)Shenghong Key Scientific Research Project of Emergency Support and Public Safety Fiber Materials and Products(2022-rw0101)Science and Technology Guidance Program of China National Textile and Apparel Council(2022002).
文摘Firefighting protective clothing is a crucial protective equipment for firefighters to minimize skin burn and ensure safety firefighting operation and rescue mission.A recent increasing concern is to develop self-powered fire warning materials that can be incorporated into the firefighting clothing to achieve active fire protection for firefighters before the protective clothing catches fire on fireground.However,it is still a challenge to facilely design and manufacture thermoelectric(TE)textile(TET)-based fire warning electronics with dynamic surface conformability and breathability.Here,we develop an alternate coaxial wet-spinning strategy to continuously produce alternating p/n-type TE aerogel fibers involving n-type Ti_(3)C_(2)T_(x)MXene and p-type MXene/SWCNT-COOH as core materials,and tough aramid nanofiber as protective shell,which simultaneously ensure the flexibility and high-efficiency TE power generation.With such alternating p/n-type TE fibers,TET-based self-powered fire warning sensors with high mechanical stability and wearability are successfully fabricated through stitching the alternating p-n segment TE fibers into aramid fabric.The results indicate that TET-based fire warning electronics containing 50 p-n pairs produce the open-circuit voltage of 7.5 mV with a power density of 119.79 nW cm-2 at a temperature difference of 300℃.The output voltage signal is then calculated as corresponding surface temperature of firefighting clothing based on a linear relationship between TE voltage and temperature.The fire alarm response time and flame-retardant properties are further displayed.Such self-powered fire warning electronics are true textiles that offer breathability and compatibility with body movement,demonstrating their potential application in firefighting clothing.
基金financial support from the National Natural Science Foundation of China(Nos.52171089 and 51571202)Ling Chuang Research Project of China National Nuclear Corporation。
文摘The development of smart coatings with potential for active anticorrosion and self-healing protection of metals is essential for long-term performance of metallic structures in aggressive chemical environments.Presently,emphasis has been placed on the development of advanced smart coatings for corrosion protection in different applications.Innovative multifunctional coatings with fascinating stimuliresponsive functionalities are considered“smart”.The stimuli-responsive functionalities of these smart coatings when properly harnessed result in a class of coatings with inherent autonomous control of corrosion.Fundamentally,when metals are exposed to aggressive environments,occurrences at the metalsolution interface cause environmental changes.These changes can be controlled when triggers from external environment set off active components of smart coating,thereby enhancing coating’s life and functionality.Common triggers include the availability of moisture,concentration of chloride ion,p H gradient,mechanical damage,impact,fatigue,light,redox activity and temperature.In this review,recent technological trends in active anticorrosion and self-healing coatings as functional routes for metal protection are summarized,stimuli responsiveness and mechanisms of inhibition are discussed,and recent multi-action protective systems are particularly focused on.
基金the support of the RTI2018-096391-B-C33 FEDER/Ministerio de Ciencia e Innovación-Agencia Estatal de InvestigaciónS2018/NMT-4411 Regional Government of Madrid+2 种基金EU Structural and Social Funds and PID2021-124341OBC22(MCIU/AEI/FEDER,UE)the support of RYC-201721843,Ministerio de Ciencia e Innovaciónsupported by the Royal Academy of Engineering through the RAEng Research Fellowship and by EPSRC(EP/V026097/1)。
文摘Zinc aluminium(Zn-Al)and lithium aluminium(Li-Al)–layered double hydroxides(LDH)coatings with incorporated inhibitors(Li-,Mo-and W-based)were successfully synthesized on AZ31 Mg alloy.Zn-Al LDH W and Li-Al LDH Li showed the highest corrosion resistance and were selected for further evaluation.SEM cross-section examination revealed a bi-layer structure composed of an outer part with loose flakes and a denser inner layer.XRD,FTIR,and XPS analysis confirmed the incorporation of the inhibitors.Post-treatments with corrosion inhibitors containing solutions resulted in the selective dissolution of the most external layer of the LDH coating,reducing the surface roughness,hydrophilicity and paint adhesion of the layers.Active corrosion properties were confirmed by SVET evaluation for the Zn-Al LDH W coating.The proposed active corrosion mechanism involves the ion-exchange of aggressive Cl-ions,deposition of hydroxides and competitive adsorption of W-rich corrosion inhibitors.
基金supported by National Science Foundation of China[No.81172620]。
文摘In recent decades,the potential health hazards of microwave exposure have been attracting increasing attention.Our previous studies have demonstrated that microwave exposure impaired learning and memory in experimental animal models[1,2].
基金supported by the National Science and Technology Support Program (No. 2011BAD14B04)Project of Shandong Province Higher Educational Science and Technology Program (J14LE59)+1 种基金Applied & Basic Research Foundation of Qingdao (No. 12-1-4-3(3)-jch)Science & Technology Project of AQSIQ (No. 2012IK176)
文摘In the present research, the strain SLYY-3 was isolated from sediments of Jiaozhou Bay, Qingdao, China. The strain SLYY- 3, which produced a bacteriocin-like substance （BLS）, was characterized to be a strain of Bacillus subtillis by biochemical profiling and 16S rDNA sequence analysis. It is the first time to report that Bacillus subtilis from Jiaozhou Bay sediments could produce a BLS. The BLS of B. subtillis SLYY-3 exhibited strong inhibitory activity against gram-positive bacteria （including Staphylococcus aureus and B. subtillis） and some fimgi （including Penicillium glaucum, Aspergillus niger and Aspergillus flavus）. The antimicrobial activity was detected from culture in the exponential growth phase and reached its maximum when culture entered into stationary growth phase. It was thermo-tolerant even when being kept at 100~C for 60 min without losing any activity and stable over a wide pH range from 1.0 to 12.0 while being inactivated by proteolytic enzyme and trypsin, indicating the proteinaceous nature of the BLS. The BLS was purified by precipitation with hydrochloric acid （HC1） and gel filteration （Sephadex G-100）. SDS-PAGE analysis of the extracellular peptides of SLYY-3 revealed a bacteriocin-like protein with a molecular mass of 66 kDa. Altogether, these characteristics indicate the potential of the BLS for food industry as a protection against pathogenic and spoilage microorganisms.
基金supported by the National Natural Science Foundation of China(31471704,31772045)
文摘In order to effectively protect the activity of Epigallocatechin gallate（EGCG）, we explored the protection mechanism of Konjac glucomannan（KGM） for EGCG by experiments and theory analyses. We synthesized KGM/EGCG nanofibers by using electrostatic spinning method. The microstructure of nanofibers was characterized by SEM, FTIR, TGA, XRD and Raman spectroscopic. The formation mechanism and the protection effects of KGM/EGCG nanofibers were also discussed. The results showed that the EGCG activity was protected due to the hydrogen bonds between-OH of EGCG and KGM, and EGCG was embedded in KGM nanofiber with bead style. The reducing force and DPPH scavenging ability data indicated that KGM/EGCG nanofibers have stronger antioxidant activity than the EGCG solution under the same condition. Hence, the mosaic topological structure of KGM can effectively extend the EGCG activity.
文摘γ-amidobutyric acid (GABA) is a major inhibitory neurotransmitter in the central nervous system and mediates fast synaptic inhibition through GABAA and GABAC
基金Supported by the National Natural Science Foundation of China (No. 39470849)
文摘The neuron protective activity of the chemical constituents from Rheum nanum and Rheum sublanceolatum in vitro was investigated using cultured embryonic mouse cortical cells exposed to oxygen-glucose deprivation. The protective effect was quantitatively evaluated by measuring the lactate dehydrogenase release rate. Most of the compounds reduce the lactate dehydrogenase release rate, including emodin, chrysophanol-8-O-β-D-glucopyranoside, 6-hydroxymusizin-8-O-β-D-glucopyranoside, gnetin C, torachrysone-8-O-β-D-glucopyranoside, and maesopsin, and all possess potent neuron protective activity. Chrysophanol and aloe-emodin exhibit neuron protection only at low concentrations. Emodin-8-O-β-D-glucopyranoside protects the neuron cells at high concentration. Aloe-emodin-8-O-β-D- glucopyranoside is inactive.
基金National Key R&D Program of China,Grant/Award Numbers:2022YFB2403700,2022YFB2403705Natural Science Foundation of Chongqing,Grant/Award Number:CSTB2022NSCQ-MSX1247。
文摘Mechanical vibration defect is the key factor leading to sudden failure of gas-insulated switchgear(GIS)equipment.It is important to realise effective prediction of the me-chanical vibration state development trend of GIS equipment in order to improve its active safety protection level.This paper carried out research on the accurate prediction method and experimental validation of the mechanical vibration state and its defect severity development trend for the GIS equipment.Firstly,the deep and shallow vibration feature parameters for different mechanical defect signals were jointly extracted by time-domain features and deep belief network methods.Secondly,a new prediction model,incorporating the attention mechanism and the bidirectional gated recurrent unit(BiGRU),was constructed with the deep and shallow vibration feature parameters as inputs.Finally,the prediction trend effectiveness was verified based on the real-type GIS mechanical simulation platform and the field operation GIS equipment.Results show that the deep and shallow vibration feature extraction method proposed in this paper can characterise the mechanical defect information more comprehensively.The new prediction method of the vibration state trend based on the attention-BiGRU model shows ideal accuracy,and the predicted vibration state development trend is highly consistent with the actual,with an average absolute error of 0.063.The root mean square error(ERMSE)value of the prediction method is<5%,which reduces the relative error value at least 37% compared with the traditional prediction models.This paper provides a valuable reference for the proactive defence of GIS mechanical failure.
基金the International Cooperation in Science and Technology Innovation between Governments,National Key Research and Development Program of China(No.2018YFE0116200)the National Natural Science Foundation of China(51971040)the Fundamental Research Funds for the Central Universities(2020CDJQY-A007)。
文摘This work produced a Mg Al-layered double hydroxide by hydrothermal treatment of a plasma electrolytic oxidation(PEO)coating on magnesium alloy AZ31 in an phosphate electrolyte,followed by an ion-exchange reaction in 0.1 M phosphate solution.The coated specimens were scratched.Characterization,including utilization of the localized technique SIET,measured the pH and p Mg distributions and optical morphologies around the artificial defects during immersion in 0.05 M NaCl solution.In contrast with phosphate loaded PEO/LDHs,a stronger alkalinization area(with pH 11.4~12.3)appeared in the passive PEO specimens.Due to formation of insoluble Mg(OH)_(2)products,the p Mg map showed depletion of Mg^(2+)in this high p H area.Combined with optical morphologies and SEM images,the better self-healing ability toward defects for phosphate loaded PEO/LDHs was confirmed.
基金financially supported by the National Natural Science Foundation of China(Nos.52371088,52071347,and U20A20233)Guangdong Basic and Applied Basic Research Foundation(No.2023A1515240007)Shenzhen Science and Technology Program(No.KJZD20230923114819041).
文摘Corrosion activities and related accidents are significant issues for marine facilities,leading to considerable economic losses.Waterborne epoxy(EP)coating has been seen as one of the optimal options for corrosion protection due to its stable properties and eco-friendliness(0 g/L volatile organic compounds).Nevertheless,several intrinsic deficiencies require improvement,such as fragile mechanical properties and defects(macro and micro),resulting in the continuous deterioration of comprehensive coating performances.In this work,a novel nanocomposite coating with mechanical enhancement,intelligent self-reporting,and active protection is fabricated by integrating the functionalized and compatible graphene oxide/cerium based metal-organic framework multiscale structure(GO-CeMOF-P/M).Notably,the homogenous dispersion of GO-CeMOF-P/M and its chemical interaction with the polymer matrix effectively reduces the defects resulting from solution volatilizing and enhances the compactness,which boosts the tensile strength(32.1 MPa/8.5%)and dry adhesion force(5.8 MPa)of the coating.Additionally,the controllable responsiveness and release of multiscale nanocomposite within external environments endow intelligent active protection and self-reporting characteristics for the GO-CeMOF-P/M-EP coating,making it especially suitable for a variety of practical marine applications.Furthermore,following immersion of 80 d in the aggressive environment,Zf=0.01 Hz value of GO-CeMOF-P/M-EP coating is 1.2×10^(10)Ωcm^(2),which is 164.4 times larger than that of EP coating(7.3×10^(7)Ωcm^(2)),demonstrating remarkably strengthened anti-corrosion ability.Consequently,by offering an intriguing design strategy,the current work anticipates addressing the inherent deficiencies of EP coating and facilitating its practicality and feasibility in real sea environments.
基金supported by China National Postdoctoral Program for Innovative Talents (Grant No.:BX20220373)the Fundamental Research Funds for the Central Universities (Grant No.:YWF-23-Q-1067)Young Elite Scientists Sponsorship Program by BAST (Grant No.:BYESS2023081).
文摘Model-based control shows promising potential for engine performance improve-ment and future aero-propulsion requirements.In this paper,an auto-updating thrust variation mitigation(AuTVM)control approach using on-board model strategies is proposed for gas tur-bine aero-engines under in-service degradation effects,which aims at active thrust regulation and acceleration protection in a simultaneous way.The AuTVM control is integrated with an on-line block,based on a reliable on-board engine model,and an off-line part for the periodical update of control parameters via post-flight engine monitoring data.The core feature of the AuTVM control is a set of auto-updating loops within the on-line part,including thrust regu-lation loop,surge margin loop,turbine entry temperature loop,and the steady loop,whose con-trol parameters are periodically adjusted with increasingflight cycles.Meanwhile,an industrial sensor-based baseline controller and two tailored model-based controllers,i.e.,a thrust variation mitigation(TVM)controller withfixed gains and a self-enhancing active transient protection(SeATP)controller with pro-active transient protection and passive thrust control,are also developed as comparison bases.Numerical simulations for idle to full-power acceleration tests are carried on a validated aero-thermal turbofan engine model using publicly available degra-dation data.Simulation results demonstrate that both new engines and severely degraded en-gines regulated by the AuTVM controller show significant thrust response enhancement,compared to the baseline controller.Moreover,thrust variation at the maximum steady state of degraded engines,which exists within the SeATP controller and the baseline controller,is suppressed by the proposed AuTVM controller.Robustness analysis against degradation uncer-tainties and sensor accuracy confirms that the AuTVM controller owns a closer maximum steady-state thrust distribution to the desired value than those of the SeATP and the baseline controller while utilizing transient margins of controlled engines more effectively.Hence,the control performance of the AuTVM controller for in-service engines is guaranteed.
