To investigate how the physicochemical properties and NH3‐selective catalytic reduction(NH3‐SCR)performance of supported ceria‐based catalysts are influenced as a function of support type,a series of CeO2/SiO2,CeO2...To investigate how the physicochemical properties and NH3‐selective catalytic reduction(NH3‐SCR)performance of supported ceria‐based catalysts are influenced as a function of support type,a series of CeO2/SiO2,CeO2/γ‐Al2O3,CeO2/ZrO2,and CeO2/TiO2catalysts were prepared.The physicochemical properties were probed by means of X‐ray diffraction,Raman spectroscopy,Brunauer‐Emmett‐Teller surface area measurements,X‐ray photoelectron spectroscopy,H2‐temperature programmed reduction,and NH3‐temperature programmed desorption.Furthermore,the supported ceria‐based catalysts'catalytic performance and H2O+SO2tolerance were evaluated by the NH3‐SCR model reaction.The results indicate that out of the supported ceria‐based catalysts studied,the CeO2/γ‐Al2O3catalyst exhibits the highest catalytic activity as a result of having a high relative Ce3+/Ce4+ratio,optimum reduction behavior,and the largest total acid site concentration.Finally,the CeO2/γ‐Al2O3catalyst also presents excellent H2O+SO2tolerance during the NH3‐SCR process.展开更多
Seed germination and seedling establishment are important for the reproductive success of plants,but seeds and seedlings typically encounter constantly changing environmental conditions.By inhibiting seed germination ...Seed germination and seedling establishment are important for the reproductive success of plants,but seeds and seedlings typically encounter constantly changing environmental conditions.By inhibiting seed germination and post-germinative growth through the PYR1/PYL/RCAR ABA receptors and PP2C co-receptors,the phytohormone abscisic acid(ABA)prevents premature germination and seedling growth under unfavorable conditions.However,little is known about how the ABA-mediated inhibition of seed germination and seedling establishment is thwarted.Here,we report that ABA Signaling Terminator(ABT),a WD40 protein,efficiently switches off ABA signaling and is critical for seed germination and seedling establishment.ABT is induced by ABA in a PYR1/PYL/RCAR-PP2C-dependent manner.Overexpression of ABT promotes seed germination and seedling greening in the presence of ABA,whereas knockout of ABT has the opposite effect.We found that ABT interacts with the PYR1/PYL/RCAR and PP2C proteins,interferes with the interaction between PYR1/PYL4 and ABI1/ABI2,and hampers the inhibition of ABI1/ABI2 by ABA-bound PYR1/PYL4,thereby terminating ABA signaling.Taken together,our results reveal a core mechanism of ABA signaling termination that is critical for seed germination and seedling establishment in Arabidopsis.展开更多
BACKGROUND： Pharmacological research has shown that cactus polysaccharide （CP） has anti-oxidant, anti-inflammatory, anti-tumor, anti-aging, and immune-stimulating activities. It may also provide protective effects ...BACKGROUND： Pharmacological research has shown that cactus polysaccharide （CP） has anti-oxidant, anti-inflammatory, anti-tumor, anti-aging, and immune-stimulating activities. It may also provide protective effects against oxidative stress injuries in the rat brain. OBJECTIVE： To validate the effects of CP on H2O2-induced oxidative stress injuries in the rat cerebral cortex and hippocampal slices 30 minutes prior to injury, as well as 30 minutes and 2.5 hours after injury. DESIGN： A randomized controlled experiment. SETTINGS： Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology; Department of Pharmacology, College of Medical Science, Yangtze University. MATERIALS： A total of 50 male Sprague Dawley （SD） rats, normal grade and weighing 200 300 g, were provided by the Laboratory Animal Center of Tongji Medical College, Huazhong University of Science and Technology. The protocol was performed in accordance with ethical guidelines for the use and care of animals. Cactus polysaccharide, a dried needle crystal, was extracted from Opuntia milpa alta at the Chemistry and Environment Engineering School of Yangtze University. The following chemicals and instruments were used： 2,3,5-triphenyl tetrazolium chloride （Sigma, St Louis, Missouri, USA）; lactate dehydrogenase （LDH）, superoxide dismutase （SOD）, glutathione （GSH）, and total antioxidant competence （T-AOC） assays （Jiancheng-Bioeng Institute, Nanjing）; McIllwain tissue chopper （Mickle Laboratory Engineering, USA）; and ELISA reader and Magellan software （TECAN, Austria）. METHODS： This experiment was performed at the Department of Pharmacology, Medical College of Yangtze University, between March and June 2006. All rats were sacrificed after anesthesia. The cerebral cortex and hippocampus were dissected. Several cerebral cortex and hippocampus slices were selected as controls, while other sections were co-incubated with H2O2 for 30 minutes to induce an oxidative stress injury.展开更多
Extractive distillation(ED) is one of the most promising approaches for the separation of the azeotropic or closeboiling mixtures in the chemical industry. The purpose of this paper is to provide a broad overview of t...Extractive distillation(ED) is one of the most promising approaches for the separation of the azeotropic or closeboiling mixtures in the chemical industry. The purpose of this paper is to provide a broad overview of the recent development of key aspects in the ED process involving conceptual design, solvent selection, and separation strategies. To obtain the minimum entrainer feed flow rate and reflux ratio for the ED process, the conceptual design of azeotropic mixture separation based on a topological analysis via thermodynamic feasibility insights involving residue curve maps, univolatility lines, and unidistribution curves is presented. The method is applicable to arbitrary multicomponent mixtures and allows direct screening of design alternatives. The determination of a suitable solvent is one of the key steps to ensure an effective and economical ED process. Candidate entrainers can be obtained from heuristics or literature studies while computer aided molecular design(CAMD) has superiority in efficiency and reliability. To achieve optimized extractive distillation systems, a brief review of evaluation method for both entrainer design and selection through CAMD is presented. Extractive distillation can be operated either in continuous extractive distillation(CED) or batch extractive distillation(BED), and both modes have been well-studied depending on the advantages in flexibility and low capital costs. To improve the energy efficiency, several configurations and technological alternatives can be used for both CED and BED depending on strategies and main azeotropic feeds. The challenge and chance of the further ED development involving screening the best potential solvents and exploring the energy-intensive separation strategies are discussed aiming at promoting the industrial application of this environmentally friendly separation technique.展开更多
Effect of cerium （Ce^3＋） on growth and photosynthesis in rape seedlings exposed to two levels of ultraviolet-B radiation （UV-B, 280 - 320 nm） was studied with hydroponics under laboratory conditions. The growth o...Effect of cerium （Ce^3＋） on growth and photosynthesis in rape seedlings exposed to two levels of ultraviolet-B radiation （UV-B, 280 - 320 nm） was studied with hydroponics under laboratory conditions. The growth of rape seedlings exposed to two levels of UV-B irradiation （0.15 and 0.35 W· m^-2/T2） was both heavily restrained. The aboveground growth indices including stem （plant） height, leaf number, leaf area, leaf fresh/dry weight and stem fresh/dry weight were obviously decreased by 13.2% - 44.1% （T1） and 21 .4% - 49.3% （T2）. Compared to CK, and except active absorption area of roots, the belowground indices main root length, root volume and fresh/dry weight by 14.1% -35.6% （T1） and 20.3% - 42.6% （T2）, respectively. For Ce ＋ UV-B treatments, the aboveground and belowground growth indices were decreased by 4.1% - 23.6%, 5.2% -23.3% （Ce＋T1） and 10.8% -28.4%, 7.0% -27.8% （Ce ＋T2）, lower than those of UV-B treatments mentioned above. These results show that Ce has protective effect on plant against injury of UV-B radiation. Furthermore, the protective effect of Ce on seedlings exposed to T1 level of UV-B radiation is superior to T2 level. Chlorophyll content, net photosynthesis rate, transpiration rate, stomatal conductance and water use efficiency in UV-B treatments decrease dramatically, whereas intercellular CO2 concentration increases. Although these indices in Ce ＋ UV-B treatments decrease compared with those of CK, the decrease in Ce ＋ UV-B treatments are lower than those in UV-B treatment. This phenomenon indicates that the ecophysiological protective effect of Ce is based on improving photosynthesis in plants. The dynamic curves of photosynthesis indices show that the course of light-repair is shortened and the injury to rape seedlings by UV-B radiation stress is alleviated by Ce.展开更多
Formaldehyde, as one of the simplest reactive carbonyl species（RCS）, is regarded as a potential carcinogen and a sick house syndrome gas. Recent studies have shown that abnormally high levels of formaldehyde may res...Formaldehyde, as one of the simplest reactive carbonyl species（RCS）, is regarded as a potential carcinogen and a sick house syndrome gas. Recent studies have shown that abnormally high levels of formaldehyde may result in cognitive decline and spatial memory deficits, asthmatic symptoms,Alzheimer＇s disease, and cancer. Due to the harmfulness of high levels of formaldehyde in nature and humans, it is of great significance to further elucidate the roles and functions of formaldehyde by a noninvasive detection approach. Fluorescence imaging has become a powerful and popular tool in monitoring bio-species owing to their high sensitivity and selectivity, excellent spatiotemporal resolution and non-invasion nature. Therefore, fluorescent probes are widely applied to track and detect formaldehyde in vitro and in vivo which have attracted more and more interest recently. This review focuses on various strategies to design the fluorescent probes for detecting formaldehyde based on different recognition groups.展开更多
The contents ofMg, Al, Si, Ti, Cr, Mn, Fe, Co, Cu, Ga, As, Se, Cd, Sb, Pb and Bi in high purity nickel were determined by high resolution inductively coupled plasma mass spectrometry （HR-ICP-MS）. The sample was diss...The contents ofMg, Al, Si, Ti, Cr, Mn, Fe, Co, Cu, Ga, As, Se, Cd, Sb, Pb and Bi in high purity nickel were determined by high resolution inductively coupled plasma mass spectrometry （HR-ICP-MS）. The sample was dissolved in HNO3 and HCI by microwave digestion. Most of the spectral interferences could be avoided by measuring in the high resolution mode. The matrix effects because of the presence of excess HC1 and nickel were evaluated. Correction for matrix effects was made using Sc, Rh and T1 as internal standards. The optimum conditions for the determination were tested and discussed. The detection limits range from 0.012 to 1.76 ~tg/g depending on the type of elements. The applicability of the proposed method is also validated by the analysis of high purity nickel reference material （NIST SRM 671）. The relative standard deviation （RSD） is less than 3.3%. Results for determination of trace elements in high purity nickel were presented.展开更多
This paper aims to study characteristics and biodiversity of the Torreya fargesii community in the Jinfo Mountains to provide baseline information related to the protection of T. fargesii. The results indicated that a...This paper aims to study characteristics and biodiversity of the Torreya fargesii community in the Jinfo Mountains to provide baseline information related to the protection of T. fargesii. The results indicated that among the 5 plots(100 m2 each) set along an altitudinal gradient, 176 species of vascular plants, 136 genera and 64 families were recorded. These included 7 species of pteridophytes, 6 genera and 4 families, 3 species of gymnosperms, 3 genera and 2 families, and 166 species of angiosperms, 127 genera and 58 families. The community physiognomy was mainly dominated by phanerophytes with medium-sized herbaceous and simple leaves. The proportions of phanerophytes among the fl oristic spectrum, frequency spectrum and vegetational spectrum are 68.75%, 73.13% and 67.48% respectively. The vertical structure can be divided into the shrub and herb layers in this community. The dominant species in shrub layer were T. fargesii, Zanthoxylum ovalifolium, Rubus coreanus, Kerria japonica, Cotoneaster horizontalis etc.. The dominant herbs included Miscanthus sinensis, Carex gibba, Artemisia lactifl ora, Pteridium aquilinum var. latiusculum, Pilea notata, Aster ageratoides etc.. Species richness(S) and the Simpson(D), Shannon-Wiener(H') and Pielou evenness(Jsw) indices of shrub layer species richness are higher than those of the herb layer; the distribution of the species in the community is obviously uneven. The species richness and diversity indices increase with the rising altitude.展开更多
The hydroponic culture experiments of soybean bean seedlings were conducted to investigate the effect of lanthanum （La） on nitrogen metabolism under two different levels of elevated UV-B radiation （UV-B, 280-320 nm...The hydroponic culture experiments of soybean bean seedlings were conducted to investigate the effect of lanthanum （La） on nitrogen metabolism under two different levels of elevated UV-B radiation （UV-B, 280-320 nm）. The whole process of nitrogen metabolism involves uptake and transport of nitrate, nitrate assimilation, ammonium assimilation, amino acid biosynthesis, and protein synthesis. Compared with the control, UV-B radiation with the intensity of low level 0.15 W/m^2 and high level 0.45 W/m^2 significantly affected the whole nitrogen metabolism in soybean seedlings （p 〈 0.05）. It restricted uptake and transport of NO3^-, inhibited activity of some key nitrogen-metabolism-related enzymes, such as： nitrate reductase （NR） to the nitrate reduction, glutamine systhetase （GS） and glutamine synthase （GOGAT） to the ammonia assimilation, while it increased the content of free amino acids and decreased that of soluble protein as well. The damage effect of high level of UV-B radiation on nitrogen metabolism was greater than that of low level. And UV-B radiation promoted the activity of the anti-adversity enzyme glutamate dehydrogenase （GDH）, which reduced the toxicity of excess ammonia in plant. After pretreatment with the optimum concentration of La （20 mg/L）, La could increase the activity of NR, GS, GOGAT, and GDH, and ammonia assimilation, but decrease nitrate and ammonia accumulation. In conclusion, La could relieve the damage effect of UV-B radiation on plant by regulating nitrogen metabolism process, and its alleviating effect under low level was better than that under the high one.展开更多
Mg-Sn-Y alloys with different Sn contents(wt%)were assessed as anode candidates for Mg-air batteries.The relationship between microstructure(including the second phase,grain size,and texture)and discharge properties o...Mg-Sn-Y alloys with different Sn contents(wt%)were assessed as anode candidates for Mg-air batteries.The relationship between microstructure(including the second phase,grain size,and texture)and discharge properties of the Mg-Sn-Y alloys was examined using microstructure observation,electrochemical measurements,and galvanostatic discharge tests.The Mg-0.7Sn-1.4Y alloy had a high steady discharge voltage of 1.5225 V and a high anodic efficiency of 46.6% at 2.5 mA·cm^(-2).These good properties were related to its microstructure:small grain size of 3.8μm,uniform distribution of small second phase particles of 0.6μm,and a high content(vol%)of(1120)/(1010)orientated grains.The scanning Kelvin probe force microscopy(SKPFM)indicated that the Sn_(3)Y_(5) and MgSnY phases were effective cathodes causing micro-galvanic corrosion which promoted the dissolution of Mg matrix during the discharge process.展开更多
The effect of La on flavonoids, chlorophyll contents, and phenylalanine ammonia-lyase （PAL） activity in soybean seedlings under supplementary ultraviolet-B radiation （UV-B, 280 - 320 nm） was studied. The results s...The effect of La on flavonoids, chlorophyll contents, and phenylalanine ammonia-lyase （PAL） activity in soybean seedlings under supplementary ultraviolet-B radiation （UV-B, 280 - 320 nm） was studied. The results show that PAL activity, contents of flavonoids and chlorophyll in the plants pretreated with La （20 mg·L^- 1 ） are higher than those in CK. UV-B radiation could result in an increase in flavonoid content and PAL activity, associated with a decrease in chlorophyll content. However, the increase in the range of PAL activity and flavonoid content in UV-B treatment are lesser than those in the La treatment. The changes of flavonoid contents and PAL activity in La ＋ UV-B treatment are similar to those in UV-B treatment, and the increase in their range is higher than those in UV-B treatment. This shows that La can enhance the resistance of soybean seedling to UV-B radiation and alleviate the damage of UV-B radiation by increasing flavonoid content, chlorophyll content, and PAL activity.展开更多
The aim of this paper is to develop some basic theories of stochastic functional differential equations (SFDEs) under the local Lipschitz condition in continuous functions space C. Firstly, we establish a global exist...The aim of this paper is to develop some basic theories of stochastic functional differential equations (SFDEs) under the local Lipschitz condition in continuous functions space C. Firstly, we establish a global existence-uniqueness lemma for the SFDEs under the global Lipschitz condition in C without the linear growth condition. Then, under the local Lipschitz condition in C, we show that the non-continuable solution of SFDEs still exists if the drift coefficient and diffusion coefficient are square-integrable with respect to t when the state variable equals zero. And the solution of the considered equation must either explode at the end of the maximum existing interval or exist globally. Furthermore, some more general sufficient conditions for the global existence-uniqueness are obtained. Our conditions obtained in this paper are much weaker than some existing results. For example, we need neither the linear growth condition nor the continuous condition on the time t. Two examples are provided to show the effectiveness of the theoretical results.展开更多
In pH 4.2-5.0 Britton-Robinson buffer solution medium, fluoroquinolone antibiotics (FLQs), such as ciprofloxacin (CIP), norfloxacin (NOR), ofloxacin (OF), levofloxacin (LEV), lomefloxacin (LOM), and sparfloxacin (SPA)...In pH 4.2-5.0 Britton-Robinson buffer solution medium, fluoroquinolone antibiotics (FLQs), such as ciprofloxacin (CIP), norfloxacin (NOR), ofloxacin (OF), levofloxacin (LEV), lomefloxacin (LOM), and sparfloxacin (SPA), react with Cu (II) to form chelate cations, which further bind with erythrosine to form the ion association complexes. They can result in the changes of the absorption spectra. Simultane- ously, erythrosine fades obviously and the maximum fading wavelength is located at 526 nm. The fad- ing reactions have high sensitivities. Thus, new spectrophotometries of determination for these drugs are developed. The ion-association reactions result in the quenching of fluorescence, which also have high sensitivities. The detection limits for six antibiotics are in the range of 7.1-12.2 μg·L?1. Furthermore, the reactions can result in the enhancement of resonance Rayleigh scattering (RRS). The maximum scattering peaks of six ion-association complexes are located at 566 nm, and there are two small RRS peaks at 333 nm and 287 nm. The detection limits for fluoroquinolone antibiotics are in the range of 1.70 -3.10 μg·L?1 for RRS method. Among the above three methods, the RRS method has the highest sen- sitivity. In this work, we investigated the spectral characteristics of the absorption, fluorescence and RRS, the optimum conditions of the reactions, and the properties of the analytical chemistry. In addi- tion, the mechanism of reactions were discussed by density function theory (DFT) and AM1 methods.展开更多
Development of efficient heterostructured photocatalysts that respond to visible light remains a considerable challenge.We herein show the synthesis of ZnIn2S4/carbon quantum dot hybrid photocatalysts with flowerlike ...Development of efficient heterostructured photocatalysts that respond to visible light remains a considerable challenge.We herein show the synthesis of ZnIn2S4/carbon quantum dot hybrid photocatalysts with flowerlike microspheres via a facile solvothermal method.The ZnIn2S4/carbon quantum dot flowerlike microspheres display enhanced photocatalytic and photoelectrochemical activity compared with that of pure ZnIn2S4.With a content of only 0.5 wt%carbon quantum dots,93%of Cr(VI)is reduced under visible‐light irradiation at 40 min.As a co‐catalyst,the carbon quantum dots improve the light absorption and lengthen the lifetime of charge carriers,consequently enhancing the photocatalytic and photoelectrochemical activity.展开更多
Based on the genetic clustering from 42 microsatellite （SSR） markers with a combination of their geographic origin and germplasm characteristics, 124 maize landraces from Wuling Mountain region in China were used fo...Based on the genetic clustering from 42 microsatellite （SSR） markers with a combination of their geographic origin and germplasm characteristics, 124 maize landraces from Wuling Mountain region in China were used for constructing a core collection. Four evaluating parameters for maize landrace core collection, including mean difference percentage （MD）, variance difference percentage （VD）, coincidence rate of range （CR）, and variable rate of coefficient of variation （VR）, were assessed With 20 quantitative traits. It was shown that genetic relationships among landraces in Wuling Mountain region had the tendency to associate with their geographic origins. The 124 landraces were clustered into 18 subgroups when the coefficient of genetic similarity （GS） is 0.28. Eighteen landraces, each of which was from one subgroup, were applied to construct the core collection with a sampling percentage of 15%. Comparison of the initial and core collection indicated that there existed no significant differences in most quantitative traits. An average of 6.3 and 6.5 alleles were detected in the initial and core collection, respectively. Mean polymorphism information content in the core collection （0.75） was higher than that in the initial one （0.72）. MD was lesser than 20% and CR was more than 80%. The results showed that the sampling strategy would be feasible for constructing the core collection that well represents the genetic diversity of the initial one.展开更多
The Yangtze River is the mother river of China.To promote the aquatic ecosystem protection of the great river,the Project of Yangtze Fisheries Resources and Environment Investigation(2017-2021)supported by the Ministr...The Yangtze River is the mother river of China.To promote the aquatic ecosystem protection of the great river,the Project of Yangtze Fisheries Resources and Environment Investigation(2017-2021)supported by the Ministry of Agriculture and Rural Affairs,P.R.China carried out by 24 institutes and universities that located in the Yangtze River basin surveys the status of(1)fish species composition and spatial distribution,(2)current fish abundance,(3)endangered fishes,(4)Yangtze finless porpoise,(5)aquatic eco-environments,(6)water-level fluctuation areas,(7)capture fisheries and recreational fisheries of the Yangtze River mainstream and 10 of its main tributaries,including Yalong River,Heng River,Min River(including Dadu River),Chishui River,Tuo River,Jialing River,Wu River,Han River,Dongting Lake and Poyang Lake.The results showed that there were 443 fish species(belonging to 163 genus,37 families,and 18 orders)before 2017,but only 323 fish species(including 15 new recorded exotic species)were recorded in the project of 2017-2021.Among them,Cyprinus carpio,Carassius auratus,Hypophthalmichthys molitrix,Pelteobagrus fulvidraco,Coilia brachygnathus,Silurus asotus,Saurogobio dabryi,Ctenopharyngodon idellus,Pelteobagrus nitidus,Hemiculter leucisculus,Siniperca chuatsi,Coreius heterodon,Culter alburnus,Parabramis pekinensis,and Aristichthys nobilis were the dominant species across the whole Yangtze River system.It is estimated that there were 886 million individuals weighing 124.8 million kg,merely equivalent to 27.3%of the resources in 1950s,30.9%of the resources in 1960s,or 58.7%of the resources in 1980s.In the new list of protected fishes that recorded in the Yangtze River system,only 15 of 29 were collected in this project of 2017-2021.Psephurus gladius has been affirmed to be Extinct by International Union for Conservation of Nature(IUCN).The wild individuals of Tenualosa reevesii and Luciobrama macrocephalus have disappeared for many years and maybe have been extinct already.Acipenser dabryanus has been affirmed to展开更多
In this paper, we consider lower order rectangular finite element methods for the singularly perturbed Stokes problem. The model problem reduces to a linear Stokes problem when the perturbation parameter is large and ...In this paper, we consider lower order rectangular finite element methods for the singularly perturbed Stokes problem. The model problem reduces to a linear Stokes problem when the perturbation parameter is large and degenerates to a mixed formulation of Poisson＇s equation as the perturbation parameter tends to zero. We propose two 2D and two 3D nonconforming rectangular finite elements, and derive robust discretization error estimates. Numerical experiments are carried out to verify the theoretical results.展开更多
This study explored the effects of butylated hydroxytoluene(BHT) and ethoxyquin(EQ) and ethyl ether extracts, ethyl acetate extracts(EAE), acetone extracts, ethanol extracts and aqueous extracts of Ginkgo biloba leave...This study explored the effects of butylated hydroxytoluene(BHT) and ethoxyquin(EQ) and ethyl ether extracts, ethyl acetate extracts(EAE), acetone extracts, ethanol extracts and aqueous extracts of Ginkgo biloba leaves(EGbs) on lipid oxidation in a linoleic acid emulsion, fish flesh and fish feed and in hydroxyl radical(·OH)-treated carp erythrocytes. The linoleic acid, fish flesh and fish feed were incubated with BHT,EQ and EGbs at 45℃ for 8 d, respectively, except for the control group. The lipid oxidation in the linoleic acid emulsion, fish flesh and fish feed was then measured by the ferric thiocyanate method or thiobarbituric acid method. The carp erythrocytes were treated with BHT, EQ. or EGbs in the presence of40 μmol/L FeSO_4 and 20 μmol/L H_2 O_2 at 37℃ for 6 h,except for the control group. Oxidative stress and apoptosis parameters in carp erythrocytes were then evaluated by the commercial kit. The results showed that BHT, EQ and EGbs inhibited lipid oxidation in the linoleic acid emulsion, fish flesh and fish feed and·OH-induced phosphatidylserine exposure and DNA fragmentation(the biomarkers of apoptosis) in carp erythrocytes. Furthermore, BHT, EQ and EGbs decreased the generation of reactive oxygen species(ROS),inhibited the oxidation of cellular components and restored the activities of enzymatic antioxidants in·OH-treated carp erythrocytes. Of all examined EGbs, EAE showed the strongest effects. The effects of EAE on lipid oxidation in the linoleic acid emulsion and on superoxide anion and malonaldehyde levels,catalase activity and apoptosis in. OH-treated carp erythrocytes were equivalent to or stronger than those of BHT. Moreover, these results indicated that the inhibition order of EGbs on the generation of ROS and oxidation of cellular components in fish erythrocytes approximately agreed with that for the food and feed materials tested above. And, the antioxidative and anti-apoptotic effects of EGbs were positively correlated with their flavonoid content. Taken together, these results r展开更多
Cell wall invertase(CWIN)are known to play important roles in seed development.However,most reports to date have focused on a single gene family member,and have mainly investigated CWIN functions during the filling st...Cell wall invertase(CWIN)are known to play important roles in seed development.However,most reports to date have focused on a single gene family member,and have mainly investigated CWIN functions during the filling stage of seed development.In this study,we found significant lower levels of CWIN protein and activity associated with seed abortion in the Litchi chinensis cultivar“Nuomici.”We identified five litchi CWIN genes and observed that the expression of LcCWIN5 was limited to the flower tissues and decreased sharply with fruit development.Silencing of LcCWIN5 expression before 28 DAA(cell division stage)resulted in perturbed liquid endosperm development,smaller seeds,and higher seed abortion rate,while silencing after 28 DAA(filling stage)had no effect on seed development.In contrast,LcCWIN2 was mostly expressed in the funicle and seed coat,and increased with fruit development.Decreased LcCWIN2 expression and CWIN activity during early seed filling coincided with smaller seeds in the cultivar“Feizixiao.”Silencing of LcCWIN2 caused a reduction in the seed size without inducing seed abortion.We propose that CWIN activity in seed maternal tissues during cell division stage is likely due to LcCWIN5 expression,which regulates early seed development.On the other hand,CWIN activity during the filling stage is due to the expression of LcCWIN2,which may promote carbon import by creating a sucrose gradient.Comparable LcCWIN5 expression,but much lower CWIN activity,detected in the funicle of“Nuomici”is consistent with post-translational regulation.展开更多
The effect of lanthanum （Ⅲ） on reactive oxygen metabolism of soybean seedlings under elevated ultraviolet-B radiation（UV-B：280~320 nm）at 0.15 and 0.45 W·cm-2 levels respectively was studied through hydropon...The effect of lanthanum （Ⅲ） on reactive oxygen metabolism of soybean seedlings under elevated ultraviolet-B radiation（UV-B：280~320 nm）at 0.15 and 0.45 W·cm-2 levels respectively was studied through hydroponics in the laboratory.Plasmolemma permeability and contents of malonadialdehyde（MDA）,hydrogen peroxide（H2O2）,and proline gradually increased during the imposition of UV-B radiation and subsequently decreased during recovery from UV-B stress.The dynamic tendency of catalase（CAT）activity was similar to that of the above four indices.The activity of peroxidase（POD）initially increased,then remained at a high level,and finally dropped steeply when soybean seedlings were exposed to a low dosage of UV-B radiation.However,POD activity rose throughout and declined slightly on the eleventh day when soybean seedlings were stressed by a high dosage.With the addition of La （Ⅲ） of 20 mg·L-1,the rising tendency of plasmolemma permeability and contents of MDA,H2O2,and proline were slowed down during the stress period,whereas the declining speed was accelerated during the recovery period.The activities of CAT and POD were higher than those without La （Ⅲ） in all experiments.It suggested that the regulative effect of La （Ⅲ） on antioxidant enzymes such as CAT and POD could strengthen their capacities to scavenge reactive oxygen species（ROS）,decrease contents of MDA and proline,and maintain normal plasmolemma permeability.Further more,the protective potential of La （Ⅲ） was better under low UV-B radiation than under a high one.展开更多
基金supported by the National Natural Science Foundation of China (21507130)the Chongqing Science and Technology Commission (cstc2016jcyjA 0070,cstc2014pt-gc20002,cstc2014yykfC 20003,cstckjcxljrc13)the Open Project Program of Chongqing Key Laboratory of Ca-talysis and Functional Organic Molecules from Chongqing Technology and Business University (1456029)~~
文摘To investigate how the physicochemical properties and NH3‐selective catalytic reduction(NH3‐SCR)performance of supported ceria‐based catalysts are influenced as a function of support type,a series of CeO2/SiO2,CeO2/γ‐Al2O3,CeO2/ZrO2,and CeO2/TiO2catalysts were prepared.The physicochemical properties were probed by means of X‐ray diffraction,Raman spectroscopy,Brunauer‐Emmett‐Teller surface area measurements,X‐ray photoelectron spectroscopy,H2‐temperature programmed reduction,and NH3‐temperature programmed desorption.Furthermore,the supported ceria‐based catalysts'catalytic performance and H2O+SO2tolerance were evaluated by the NH3‐SCR model reaction.The results indicate that out of the supported ceria‐based catalysts studied,the CeO2/γ‐Al2O3catalyst exhibits the highest catalytic activity as a result of having a high relative Ce3+/Ce4+ratio,optimum reduction behavior,and the largest total acid site concentration.Finally,the CeO2/γ‐Al2O3catalyst also presents excellent H2O+SO2tolerance during the NH3‐SCR process.
基金supported by the National Key Research and Development Program of China(2016YFA0500503)the Fundamental Research Funds for the Central Universities(2662018PY075)+1 种基金the National Natural Science Foundation of China(31730066,91540112)the Huazhong Agricultural University's Scientific and Technological Self-innovation Foundation(2015RC014).
文摘Seed germination and seedling establishment are important for the reproductive success of plants,but seeds and seedlings typically encounter constantly changing environmental conditions.By inhibiting seed germination and post-germinative growth through the PYR1/PYL/RCAR ABA receptors and PP2C co-receptors,the phytohormone abscisic acid(ABA)prevents premature germination and seedling growth under unfavorable conditions.However,little is known about how the ABA-mediated inhibition of seed germination and seedling establishment is thwarted.Here,we report that ABA Signaling Terminator(ABT),a WD40 protein,efficiently switches off ABA signaling and is critical for seed germination and seedling establishment.ABT is induced by ABA in a PYR1/PYL/RCAR-PP2C-dependent manner.Overexpression of ABT promotes seed germination and seedling greening in the presence of ABA,whereas knockout of ABT has the opposite effect.We found that ABT interacts with the PYR1/PYL/RCAR and PP2C proteins,interferes with the interaction between PYR1/PYL4 and ABI1/ABI2,and hampers the inhibition of ABI1/ABI2 by ABA-bound PYR1/PYL4,thereby terminating ABA signaling.Taken together,our results reveal a core mechanism of ABA signaling termination that is critical for seed germination and seedling establishment in Arabidopsis.
基金the Science Foundation of Hubei Provincial Department of Education, No. Q200712004
文摘BACKGROUND： Pharmacological research has shown that cactus polysaccharide （CP） has anti-oxidant, anti-inflammatory, anti-tumor, anti-aging, and immune-stimulating activities. It may also provide protective effects against oxidative stress injuries in the rat brain. OBJECTIVE： To validate the effects of CP on H2O2-induced oxidative stress injuries in the rat cerebral cortex and hippocampal slices 30 minutes prior to injury, as well as 30 minutes and 2.5 hours after injury. DESIGN： A randomized controlled experiment. SETTINGS： Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology; Department of Pharmacology, College of Medical Science, Yangtze University. MATERIALS： A total of 50 male Sprague Dawley （SD） rats, normal grade and weighing 200 300 g, were provided by the Laboratory Animal Center of Tongji Medical College, Huazhong University of Science and Technology. The protocol was performed in accordance with ethical guidelines for the use and care of animals. Cactus polysaccharide, a dried needle crystal, was extracted from Opuntia milpa alta at the Chemistry and Environment Engineering School of Yangtze University. The following chemicals and instruments were used： 2,3,5-triphenyl tetrazolium chloride （Sigma, St Louis, Missouri, USA）; lactate dehydrogenase （LDH）, superoxide dismutase （SOD）, glutathione （GSH）, and total antioxidant competence （T-AOC） assays （Jiancheng-Bioeng Institute, Nanjing）; McIllwain tissue chopper （Mickle Laboratory Engineering, USA）; and ELISA reader and Magellan software （TECAN, Austria）. METHODS： This experiment was performed at the Department of Pharmacology, Medical College of Yangtze University, between March and June 2006. All rats were sacrificed after anesthesia. The cerebral cortex and hippocampus were dissected. Several cerebral cortex and hippocampus slices were selected as controls, while other sections were co-incubated with H2O2 for 30 minutes to induce an oxidative stress injury.
基金Supported by the National Natural Science Foundation of China(No.21878028,21606026)the Fundamental Research Funds for the Central Universities(No.106112017CDJQJ228809)+2 种基金Chongqing Technological Innovation and Application Demonstration for Social and Livelihood development(No.cstc2018jscx-msyb X0336)Chongqing Research Program of Basic Research and Frontier Technology(No.CSTC2016JCYJA0474)Hundred Talents Program of Chongqing University
文摘Extractive distillation(ED) is one of the most promising approaches for the separation of the azeotropic or closeboiling mixtures in the chemical industry. The purpose of this paper is to provide a broad overview of the recent development of key aspects in the ED process involving conceptual design, solvent selection, and separation strategies. To obtain the minimum entrainer feed flow rate and reflux ratio for the ED process, the conceptual design of azeotropic mixture separation based on a topological analysis via thermodynamic feasibility insights involving residue curve maps, univolatility lines, and unidistribution curves is presented. The method is applicable to arbitrary multicomponent mixtures and allows direct screening of design alternatives. The determination of a suitable solvent is one of the key steps to ensure an effective and economical ED process. Candidate entrainers can be obtained from heuristics or literature studies while computer aided molecular design(CAMD) has superiority in efficiency and reliability. To achieve optimized extractive distillation systems, a brief review of evaluation method for both entrainer design and selection through CAMD is presented. Extractive distillation can be operated either in continuous extractive distillation(CED) or batch extractive distillation(BED), and both modes have been well-studied depending on the advantages in flexibility and low capital costs. To improve the energy efficiency, several configurations and technological alternatives can be used for both CED and BED depending on strategies and main azeotropic feeds. The challenge and chance of the further ED development involving screening the best potential solvents and exploring the energy-intensive separation strategies are discussed aiming at promoting the industrial application of this environmentally friendly separation technique.
文摘Effect of cerium （Ce^3＋） on growth and photosynthesis in rape seedlings exposed to two levels of ultraviolet-B radiation （UV-B, 280 - 320 nm） was studied with hydroponics under laboratory conditions. The growth of rape seedlings exposed to two levels of UV-B irradiation （0.15 and 0.35 W· m^-2/T2） was both heavily restrained. The aboveground growth indices including stem （plant） height, leaf number, leaf area, leaf fresh/dry weight and stem fresh/dry weight were obviously decreased by 13.2% - 44.1% （T1） and 21 .4% - 49.3% （T2）. Compared to CK, and except active absorption area of roots, the belowground indices main root length, root volume and fresh/dry weight by 14.1% -35.6% （T1） and 20.3% - 42.6% （T2）, respectively. For Ce ＋ UV-B treatments, the aboveground and belowground growth indices were decreased by 4.1% - 23.6%, 5.2% -23.3% （Ce＋T1） and 10.8% -28.4%, 7.0% -27.8% （Ce ＋T2）, lower than those of UV-B treatments mentioned above. These results show that Ce has protective effect on plant against injury of UV-B radiation. Furthermore, the protective effect of Ce on seedlings exposed to T1 level of UV-B radiation is superior to T2 level. Chlorophyll content, net photosynthesis rate, transpiration rate, stomatal conductance and water use efficiency in UV-B treatments decrease dramatically, whereas intercellular CO2 concentration increases. Although these indices in Ce ＋ UV-B treatments decrease compared with those of CK, the decrease in Ce ＋ UV-B treatments are lower than those in UV-B treatment. This phenomenon indicates that the ecophysiological protective effect of Ce is based on improving photosynthesis in plants. The dynamic curves of photosynthesis indices show that the course of light-repair is shortened and the injury to rape seedlings by UV-B radiation stress is alleviated by Ce.
基金support from National Natural Science Foundation of China (Nos. 21676113, 21402057, 21472059, 81671803) Youth Chen-Guang Project of Wuhan(2016070204010098)+2 种基金 the 111 Project B17019the Ministry-Province Jointly Constructed Base for State Key Lab-Shenzhen Key Laboratory of Chemical Biology, Shenzhensupported by self-determined research funds of CCNU from the colleges’ basic research and operation of MOE (No. CCNU16A02004)
文摘Formaldehyde, as one of the simplest reactive carbonyl species（RCS）, is regarded as a potential carcinogen and a sick house syndrome gas. Recent studies have shown that abnormally high levels of formaldehyde may result in cognitive decline and spatial memory deficits, asthmatic symptoms,Alzheimer＇s disease, and cancer. Due to the harmfulness of high levels of formaldehyde in nature and humans, it is of great significance to further elucidate the roles and functions of formaldehyde by a noninvasive detection approach. Fluorescence imaging has become a powerful and popular tool in monitoring bio-species owing to their high sensitivity and selectivity, excellent spatiotemporal resolution and non-invasion nature. Therefore, fluorescent probes are widely applied to track and detect formaldehyde in vitro and in vivo which have attracted more and more interest recently. This review focuses on various strategies to design the fluorescent probes for detecting formaldehyde based on different recognition groups.
基金Project(21075138) supported by the National Natural Science Foundation of ChinaProject(cstc2011jjA0780) supported by Natural Science Foundation of Chongqing City,ChinaProject(KJ121311) supported by Educational Commission of Chongqing City of China
文摘The contents ofMg, Al, Si, Ti, Cr, Mn, Fe, Co, Cu, Ga, As, Se, Cd, Sb, Pb and Bi in high purity nickel were determined by high resolution inductively coupled plasma mass spectrometry （HR-ICP-MS）. The sample was dissolved in HNO3 and HCI by microwave digestion. Most of the spectral interferences could be avoided by measuring in the high resolution mode. The matrix effects because of the presence of excess HC1 and nickel were evaluated. Correction for matrix effects was made using Sc, Rh and T1 as internal standards. The optimum conditions for the determination were tested and discussed. The detection limits range from 0.012 to 1.76 ~tg/g depending on the type of elements. The applicability of the proposed method is also validated by the analysis of high purity nickel reference material （NIST SRM 671）. The relative standard deviation （RSD） is less than 3.3%. Results for determination of trace elements in high purity nickel were presented.
基金Supported by National Natural Science Foundation of China(31470568)Project of Scientifi c Research Innovation Team of Yangtze Normal University(2014XJTD06)
文摘This paper aims to study characteristics and biodiversity of the Torreya fargesii community in the Jinfo Mountains to provide baseline information related to the protection of T. fargesii. The results indicated that among the 5 plots(100 m2 each) set along an altitudinal gradient, 176 species of vascular plants, 136 genera and 64 families were recorded. These included 7 species of pteridophytes, 6 genera and 4 families, 3 species of gymnosperms, 3 genera and 2 families, and 166 species of angiosperms, 127 genera and 58 families. The community physiognomy was mainly dominated by phanerophytes with medium-sized herbaceous and simple leaves. The proportions of phanerophytes among the fl oristic spectrum, frequency spectrum and vegetational spectrum are 68.75%, 73.13% and 67.48% respectively. The vertical structure can be divided into the shrub and herb layers in this community. The dominant species in shrub layer were T. fargesii, Zanthoxylum ovalifolium, Rubus coreanus, Kerria japonica, Cotoneaster horizontalis etc.. The dominant herbs included Miscanthus sinensis, Carex gibba, Artemisia lactifl ora, Pteridium aquilinum var. latiusculum, Pilea notata, Aster ageratoides etc.. Species richness(S) and the Simpson(D), Shannon-Wiener(H') and Pielou evenness(Jsw) indices of shrub layer species richness are higher than those of the herb layer; the distribution of the species in the community is obviously uneven. The species richness and diversity indices increase with the rising altitude.
基金Project supported by the National Natural Science Foundation of China(No.30570323)Foundation of State Developing and Reforming Committee(No.IFZ20051210)
文摘The hydroponic culture experiments of soybean bean seedlings were conducted to investigate the effect of lanthanum （La） on nitrogen metabolism under two different levels of elevated UV-B radiation （UV-B, 280-320 nm）. The whole process of nitrogen metabolism involves uptake and transport of nitrate, nitrate assimilation, ammonium assimilation, amino acid biosynthesis, and protein synthesis. Compared with the control, UV-B radiation with the intensity of low level 0.15 W/m^2 and high level 0.45 W/m^2 significantly affected the whole nitrogen metabolism in soybean seedlings （p 〈 0.05）. It restricted uptake and transport of NO3^-, inhibited activity of some key nitrogen-metabolism-related enzymes, such as： nitrate reductase （NR） to the nitrate reduction, glutamine systhetase （GS） and glutamine synthase （GOGAT） to the ammonia assimilation, while it increased the content of free amino acids and decreased that of soluble protein as well. The damage effect of high level of UV-B radiation on nitrogen metabolism was greater than that of low level. And UV-B radiation promoted the activity of the anti-adversity enzyme glutamate dehydrogenase （GDH）, which reduced the toxicity of excess ammonia in plant. After pretreatment with the optimum concentration of La （20 mg/L）, La could increase the activity of NR, GS, GOGAT, and GDH, and ammonia assimilation, but decrease nitrate and ammonia accumulation. In conclusion, La could relieve the damage effect of UV-B radiation on plant by regulating nitrogen metabolism process, and its alleviating effect under low level was better than that under the high one.
文摘Mg-Sn-Y alloys with different Sn contents(wt%)were assessed as anode candidates for Mg-air batteries.The relationship between microstructure(including the second phase,grain size,and texture)and discharge properties of the Mg-Sn-Y alloys was examined using microstructure observation,electrochemical measurements,and galvanostatic discharge tests.The Mg-0.7Sn-1.4Y alloy had a high steady discharge voltage of 1.5225 V and a high anodic efficiency of 46.6% at 2.5 mA·cm^(-2).These good properties were related to its microstructure:small grain size of 3.8μm,uniform distribution of small second phase particles of 0.6μm,and a high content(vol%)of(1120)/(1010)orientated grains.The scanning Kelvin probe force microscopy(SKPFM)indicated that the Sn_(3)Y_(5) and MgSnY phases were effective cathodes causing micro-galvanic corrosion which promoted the dissolution of Mg matrix during the discharge process.
基金Project supported by the National Natural Science Foundation of China (20471030)the Foundation of State PlanningCommittee (IFZ20051210)
文摘The effect of La on flavonoids, chlorophyll contents, and phenylalanine ammonia-lyase （PAL） activity in soybean seedlings under supplementary ultraviolet-B radiation （UV-B, 280 - 320 nm） was studied. The results show that PAL activity, contents of flavonoids and chlorophyll in the plants pretreated with La （20 mg·L^- 1 ） are higher than those in CK. UV-B radiation could result in an increase in flavonoid content and PAL activity, associated with a decrease in chlorophyll content. However, the increase in the range of PAL activity and flavonoid content in UV-B treatment are lesser than those in the La treatment. The changes of flavonoid contents and PAL activity in La ＋ UV-B treatment are similar to those in UV-B treatment, and the increase in their range is higher than those in UV-B treatment. This shows that La can enhance the resistance of soybean seedling to UV-B radiation and alleviate the damage of UV-B radiation by increasing flavonoid content, chlorophyll content, and PAL activity.
基金supported by National Natural Science Foundation of China (Grant Nos.11271270, 11201320 and 11101298)Youth Foundation of Sichuan University (Grant No. 2011SCU11111)
文摘The aim of this paper is to develop some basic theories of stochastic functional differential equations (SFDEs) under the local Lipschitz condition in continuous functions space C. Firstly, we establish a global existence-uniqueness lemma for the SFDEs under the global Lipschitz condition in C without the linear growth condition. Then, under the local Lipschitz condition in C, we show that the non-continuable solution of SFDEs still exists if the drift coefficient and diffusion coefficient are square-integrable with respect to t when the state variable equals zero. And the solution of the considered equation must either explode at the end of the maximum existing interval or exist globally. Furthermore, some more general sufficient conditions for the global existence-uniqueness are obtained. Our conditions obtained in this paper are much weaker than some existing results. For example, we need neither the linear growth condition nor the continuous condition on the time t. Two examples are provided to show the effectiveness of the theoretical results.
基金Supported by the National Natural Science Foundation of China (Grant No. 20475045)
文摘In pH 4.2-5.0 Britton-Robinson buffer solution medium, fluoroquinolone antibiotics (FLQs), such as ciprofloxacin (CIP), norfloxacin (NOR), ofloxacin (OF), levofloxacin (LEV), lomefloxacin (LOM), and sparfloxacin (SPA), react with Cu (II) to form chelate cations, which further bind with erythrosine to form the ion association complexes. They can result in the changes of the absorption spectra. Simultane- ously, erythrosine fades obviously and the maximum fading wavelength is located at 526 nm. The fad- ing reactions have high sensitivities. Thus, new spectrophotometries of determination for these drugs are developed. The ion-association reactions result in the quenching of fluorescence, which also have high sensitivities. The detection limits for six antibiotics are in the range of 7.1-12.2 μg·L?1. Furthermore, the reactions can result in the enhancement of resonance Rayleigh scattering (RRS). The maximum scattering peaks of six ion-association complexes are located at 566 nm, and there are two small RRS peaks at 333 nm and 287 nm. The detection limits for fluoroquinolone antibiotics are in the range of 1.70 -3.10 μg·L?1 for RRS method. Among the above three methods, the RRS method has the highest sen- sitivity. In this work, we investigated the spectral characteristics of the absorption, fluorescence and RRS, the optimum conditions of the reactions, and the properties of the analytical chemistry. In addi- tion, the mechanism of reactions were discussed by density function theory (DFT) and AM1 methods.
文摘Development of efficient heterostructured photocatalysts that respond to visible light remains a considerable challenge.We herein show the synthesis of ZnIn2S4/carbon quantum dot hybrid photocatalysts with flowerlike microspheres via a facile solvothermal method.The ZnIn2S4/carbon quantum dot flowerlike microspheres display enhanced photocatalytic and photoelectrochemical activity compared with that of pure ZnIn2S4.With a content of only 0.5 wt%carbon quantum dots,93%of Cr(VI)is reduced under visible‐light irradiation at 40 min.As a co‐catalyst,the carbon quantum dots improve the light absorption and lengthen the lifetime of charge carriers,consequently enhancing the photocatalytic and photoelectrochemical activity.
基金the National High Tech-nology Research and Development Program of China(863 Program, 2004BA525B04)Program for Changjiang Scholars and Innovative Research Team in University of China (IRTO453)
文摘Based on the genetic clustering from 42 microsatellite （SSR） markers with a combination of their geographic origin and germplasm characteristics, 124 maize landraces from Wuling Mountain region in China were used for constructing a core collection. Four evaluating parameters for maize landrace core collection, including mean difference percentage （MD）, variance difference percentage （VD）, coincidence rate of range （CR）, and variable rate of coefficient of variation （VR）, were assessed With 20 quantitative traits. It was shown that genetic relationships among landraces in Wuling Mountain region had the tendency to associate with their geographic origins. The 124 landraces were clustered into 18 subgroups when the coefficient of genetic similarity （GS） is 0.28. Eighteen landraces, each of which was from one subgroup, were applied to construct the core collection with a sampling percentage of 15%. Comparison of the initial and core collection indicated that there existed no significant differences in most quantitative traits. An average of 6.3 and 6.5 alleles were detected in the initial and core collection, respectively. Mean polymorphism information content in the core collection （0.75） was higher than that in the initial one （0.72）. MD was lesser than 20% and CR was more than 80%. The results showed that the sampling strategy would be feasible for constructing the core collection that well represents the genetic diversity of the initial one.
文摘The Yangtze River is the mother river of China.To promote the aquatic ecosystem protection of the great river,the Project of Yangtze Fisheries Resources and Environment Investigation(2017-2021)supported by the Ministry of Agriculture and Rural Affairs,P.R.China carried out by 24 institutes and universities that located in the Yangtze River basin surveys the status of(1)fish species composition and spatial distribution,(2)current fish abundance,(3)endangered fishes,(4)Yangtze finless porpoise,(5)aquatic eco-environments,(6)water-level fluctuation areas,(7)capture fisheries and recreational fisheries of the Yangtze River mainstream and 10 of its main tributaries,including Yalong River,Heng River,Min River(including Dadu River),Chishui River,Tuo River,Jialing River,Wu River,Han River,Dongting Lake and Poyang Lake.The results showed that there were 443 fish species(belonging to 163 genus,37 families,and 18 orders)before 2017,but only 323 fish species(including 15 new recorded exotic species)were recorded in the project of 2017-2021.Among them,Cyprinus carpio,Carassius auratus,Hypophthalmichthys molitrix,Pelteobagrus fulvidraco,Coilia brachygnathus,Silurus asotus,Saurogobio dabryi,Ctenopharyngodon idellus,Pelteobagrus nitidus,Hemiculter leucisculus,Siniperca chuatsi,Coreius heterodon,Culter alburnus,Parabramis pekinensis,and Aristichthys nobilis were the dominant species across the whole Yangtze River system.It is estimated that there were 886 million individuals weighing 124.8 million kg,merely equivalent to 27.3%of the resources in 1950s,30.9%of the resources in 1960s,or 58.7%of the resources in 1980s.In the new list of protected fishes that recorded in the Yangtze River system,only 15 of 29 were collected in this project of 2017-2021.Psephurus gladius has been affirmed to be Extinct by International Union for Conservation of Nature(IUCN).The wild individuals of Tenualosa reevesii and Luciobrama macrocephalus have disappeared for many years and maybe have been extinct already.Acipenser dabryanus has been affirmed to
基金supported by the Natural Science Foundation of China (10771150)the National Basic Research Program of China (2005CB321701)the Program for New Century Excellent Talents in University (NCET-07-0584)
文摘In this paper, we consider lower order rectangular finite element methods for the singularly perturbed Stokes problem. The model problem reduces to a linear Stokes problem when the perturbation parameter is large and degenerates to a mixed formulation of Poisson＇s equation as the perturbation parameter tends to zero. We propose two 2D and two 3D nonconforming rectangular finite elements, and derive robust discretization error estimates. Numerical experiments are carried out to verify the theoretical results.
基金financially supported by the Doctoral Research Fund of Neijiang Normal University(14B07)
文摘This study explored the effects of butylated hydroxytoluene(BHT) and ethoxyquin(EQ) and ethyl ether extracts, ethyl acetate extracts(EAE), acetone extracts, ethanol extracts and aqueous extracts of Ginkgo biloba leaves(EGbs) on lipid oxidation in a linoleic acid emulsion, fish flesh and fish feed and in hydroxyl radical(·OH)-treated carp erythrocytes. The linoleic acid, fish flesh and fish feed were incubated with BHT,EQ and EGbs at 45℃ for 8 d, respectively, except for the control group. The lipid oxidation in the linoleic acid emulsion, fish flesh and fish feed was then measured by the ferric thiocyanate method or thiobarbituric acid method. The carp erythrocytes were treated with BHT, EQ. or EGbs in the presence of40 μmol/L FeSO_4 and 20 μmol/L H_2 O_2 at 37℃ for 6 h,except for the control group. Oxidative stress and apoptosis parameters in carp erythrocytes were then evaluated by the commercial kit. The results showed that BHT, EQ and EGbs inhibited lipid oxidation in the linoleic acid emulsion, fish flesh and fish feed and·OH-induced phosphatidylserine exposure and DNA fragmentation(the biomarkers of apoptosis) in carp erythrocytes. Furthermore, BHT, EQ and EGbs decreased the generation of reactive oxygen species(ROS),inhibited the oxidation of cellular components and restored the activities of enzymatic antioxidants in·OH-treated carp erythrocytes. Of all examined EGbs, EAE showed the strongest effects. The effects of EAE on lipid oxidation in the linoleic acid emulsion and on superoxide anion and malonaldehyde levels,catalase activity and apoptosis in. OH-treated carp erythrocytes were equivalent to or stronger than those of BHT. Moreover, these results indicated that the inhibition order of EGbs on the generation of ROS and oxidation of cellular components in fish erythrocytes approximately agreed with that for the food and feed materials tested above. And, the antioxidative and anti-apoptotic effects of EGbs were positively correlated with their flavonoid content. Taken together, these results r
基金This study was supported by the National Natural Science Fund of China(project No.31501734)the China Litchi and Longan Industry Technology Research System(project No.CARS-33-11).
文摘Cell wall invertase(CWIN)are known to play important roles in seed development.However,most reports to date have focused on a single gene family member,and have mainly investigated CWIN functions during the filling stage of seed development.In this study,we found significant lower levels of CWIN protein and activity associated with seed abortion in the Litchi chinensis cultivar“Nuomici.”We identified five litchi CWIN genes and observed that the expression of LcCWIN5 was limited to the flower tissues and decreased sharply with fruit development.Silencing of LcCWIN5 expression before 28 DAA(cell division stage)resulted in perturbed liquid endosperm development,smaller seeds,and higher seed abortion rate,while silencing after 28 DAA(filling stage)had no effect on seed development.In contrast,LcCWIN2 was mostly expressed in the funicle and seed coat,and increased with fruit development.Decreased LcCWIN2 expression and CWIN activity during early seed filling coincided with smaller seeds in the cultivar“Feizixiao.”Silencing of LcCWIN2 caused a reduction in the seed size without inducing seed abortion.We propose that CWIN activity in seed maternal tissues during cell division stage is likely due to LcCWIN5 expression,which regulates early seed development.On the other hand,CWIN activity during the filling stage is due to the expression of LcCWIN2,which may promote carbon import by creating a sucrose gradient.Comparable LcCWIN5 expression,but much lower CWIN activity,detected in the funicle of“Nuomici”is consistent with post-translational regulation.
基金Project supported by the National Natural Science Foundation of China(30570323)the Foundation of State Developingand Reforming Committee(IFZ20051210)
文摘The effect of lanthanum （Ⅲ） on reactive oxygen metabolism of soybean seedlings under elevated ultraviolet-B radiation（UV-B：280~320 nm）at 0.15 and 0.45 W·cm-2 levels respectively was studied through hydroponics in the laboratory.Plasmolemma permeability and contents of malonadialdehyde（MDA）,hydrogen peroxide（H2O2）,and proline gradually increased during the imposition of UV-B radiation and subsequently decreased during recovery from UV-B stress.The dynamic tendency of catalase（CAT）activity was similar to that of the above four indices.The activity of peroxidase（POD）initially increased,then remained at a high level,and finally dropped steeply when soybean seedlings were exposed to a low dosage of UV-B radiation.However,POD activity rose throughout and declined slightly on the eleventh day when soybean seedlings were stressed by a high dosage.With the addition of La （Ⅲ） of 20 mg·L-1,the rising tendency of plasmolemma permeability and contents of MDA,H2O2,and proline were slowed down during the stress period,whereas the declining speed was accelerated during the recovery period.The activities of CAT and POD were higher than those without La （Ⅲ） in all experiments.It suggested that the regulative effect of La （Ⅲ） on antioxidant enzymes such as CAT and POD could strengthen their capacities to scavenge reactive oxygen species（ROS）,decrease contents of MDA and proline,and maintain normal plasmolemma permeability.Further more,the protective potential of La （Ⅲ） was better under low UV-B radiation than under a high one.
