Robust T_c in element molybdenum up to 160 GPa

Element superconductors with the single atoms provide clean and fundamental platforms for studying superconductivity.Although elements with d electrons are usually not favored by conventional BCS,the record superconducting critical temperature(T_(c))in element scandium(S_(c))has further ignited the intensive attention on transition metals.The element molybdenum(M_o)with a half-full d-orbital is studied in our work,which fills the gap in the study of Mo under high pressure and investigates the pressure dependence of superconductivity.In this work,we exhibit a robust superconductivity of Mo in the pressure range of 5 GPa to 160 GPa via high-pressure electrical transport measurements,the T_(c) varies at a rate of0.013 K/GPa to 8.56 K at 160 GPa.Moreover,the superconductivity is evidenced by the T_(c) shifting to lower temperature under applied magnetic fields,and the upper critical magnetic fields are extrapolated by the WHH equation and GL equation;the results indicate that the maximum upper critical magnetic field is estimated to be 8.24 T at 137 GPa.We further investigate the superconducting mechanism of Mo,the theoretical calculations indicate that the superconductivity can be attributed to the strong coupling between the electrons from the partially filled d band and the phonons from the frequency zone of 200-400 cm^(-1).

Th22 cells are associated with hepatocellular carcinoma development and progression

Objective： IL-22-producing CD4＋ T helper cells （Th22 cells） have been identified as major inducers of tissue inflammation and immune responses. Currently, no previous study explored the role of Th22 cells in the pathogenesis of hepatocellular carcinoma （HCC）. The study aimed to determine the biological function of Th22 cells and its effector IL-22 in HCC patients. Methods： Forty-five HCC patients and 19 healthy controls were recruited and their peripheral blood was collected. The flesh HCC tissues, adjacent HCC tissues and ten normal liver tissues were also collected. Flow cytometry analysis was used to determine the frequencies of circulating Th22 cells and Thl7 cells. Serum IL-22 levels were tested by enzyme-linked immtmosorbent assay （ELISA）. Immunohistochemical staining and real-time polymerase chain reaction （PCR） were used to detect IL-22 protein and mRNA in tissues specimens, respectively. Results： Circulating Th22 cells, Thl7 cells and serum IL-22 levels were significantly elevated in HCC patients compared with those of healthy controls （P〈0.001）. Th22 cells were showed to be positively correlated with IL-22 in HCC patients （P〈0.05）, but not in healthy controls. No significant differences were found in HCC patients with HBeAg positivity or negativity in term of Th22 cells and serum IL-22 levels. The expression of IL-22 protein and mRNA was highest in HCC tissues, followed by adjacent HCC tissues and normal liver tissues. Furthermore, Th22 cells, serum IL-22 levels and IL-22 mRNA were elevated at stage III-IV compared with stage I-II of HCC （P〈0.05）. Conclusions： Elevation of circulating Th22 cells and IL-22 may be implicated in the pathogenesis of HCC, and potentially be cellular targets for therapeutic intervention.

Dietary isoleucine improved flesh quality,muscle antioxidant capacity,and muscle growth associated with AKT/TOR/S6K1 and AKT/FOXO3a signaling in hybrid bagrid catfish(Pelteobagrus vachelli♀×Leiocassis longirostris♂)

Background:Muscle is the complex and heterogeneous tissue,which comprises the primary edible part of the trunk of fish and mammals.Previous studies have shown that dietary isoleucine(Ile)exerts beneficial effects on growth in aquatic animals.However,there were limited studies regarding the benefits of Ile on fish muscle and their effects on flesh quality and muscle growth.Thus,this study was conducted to explore whether dietary Ile had affected flesh quality and muscle growth in hybrid bagrid catfish(Pelteobagrus vachelli♀×Leiocassis longirostris♂).Methods:A total of 630 hybrid fish,with an initial average body weight of 33.11±0.09 g,were randomly allotted into seven experimental groups with three replicates each,and respectively fed seven diets with 5.0,7.5,10.0,12.5,15.0,17.5,and 20.0 g Ile/kg diets for 8 weeks.Results:In the present study,we demonstrated that Ile significantly:(1)increased muscle protein and lipid contents and the frequency distribution of myofibers with≤20μm and≥50μm of diameter;(2)improved pH value,shear force,cathepsin B and L activities,hydroxyproline content,resilience,cohesiveness,and decreased cooking loss,lactate content,hardness,springiness,gumminess,and chewiness;(3)decreased reactive oxygen species(ROS),malondialdehyde(MDA),and protein carbonyl(PC)contents,GCLC and Keap1 mRNA levels,and up-regulated CuZnSOD,CAT,GPX1a,GST,and Nrf2 mRNA levels;(4)up-regulated the insulin-like growth factor 1,2(IGF-1,IGF-2),insulin-like growth factor 1 receptor(IGF-1R),proliferating cell nuclear antigen(PCNA),Myf5,Myod,Myog,Mrf4,and MyHC mRNA levels,and decreased MSTN mRNAlevel;(5)increased muscle protein deposition by activating AKT-TOR-S6K1 and AKT-FOXO3a signaling pathways.Conclusion:These results revealed that dietary Ile improved flesh quality,which might be due to increasing nutritional content,physicochemical,texture parameters,and antioxidant ability;promoting muscle growth by affecting myocytes hyperplasia and hypertrophy,and muscle protein deposition associated with protein synthesis and degradation signaling pathways.Finally,the quadratic regression analysis of chewiness,ROS,and protein contents against dietary Ile levels suggested that the optimal dietary Ile levels for hybrid bagrid catfish was estimated to be 14.19,12.36,and 12.78 g/kg diet,corresponding to 36.59,31.87,and 32.96 g/kg dietary protein,respectively.

Chemical composition and phytotoxic activity of the volatile oil of invasive Xanthium italicum Moretti from Xinjiang,China

Aerial parts of Xanthium italicum in an air tight container greatly inhibited root elongation of radish, implying that this invasive plant could release biologically active volatile organic compounds （VOCs） into the environment to affect other plants＇ growth. This phenomenon was further studied by evaluating the phytotoxic effects of X. italicum essential oil against two dicot plants, amaranth （Amaranthus mangostanus L.） and lettuce （Lectuca sativa L.）, and two monocot plants, wheat （Triticum aestivum Linn） and ryegrass （Lolium multiforum）, and analyzing the chemical composition of the oil. Among the 4 test species, amaranth was the most sensitive plant, 0.5μl/mL essential oil application resulted in a 50% reduction on root elongation, and 2.5 μl/mL essential oil almost completely inhibited its seedling growth. Wheat was the least sensitive species, whose root growth was reduced to 36% of control by 5 μl/mL essential oil. The essential oil exerted moderate inhibitory effect on both lettuce and ryegrass. Compared to a commercial herbicide-Harness, X. italicum oil exhibited stronger phytotoxicity on amaranth, lettuce and wheat, but weaker activity on ryegrass. The chemical composition of the essential oil isolated by hydrodistillation from the aerial parts of X. italicum Moretti was analyzed by GC/MS. Thirty two compounds were identified, representing 94.89% of total oil, which was found to be rich in monoterpene hydrocarbons （60.71%）. The main constituents of the oil were limonene （51.61%）, germacrene B （6.98%）, 6-cadinol （5.94%）, β-pinene （5.23%）, α-caryophyllene （5.1%） and bornyl acetate （3.15%）. Bioassay revealed the dominant constituent-limonene, was unlikely the responsible phytotoxic compound due to its low biological activity; rather, there might be other oil constituent（s） that either act alone, or work together, and possibly assisted by synergistic effect, to display the phytotoxic activity. Our results suggested that X. italicum might produce allelopathic VOCs to facilitate its invasion success. This is the first report on the phytotoxic activity and the chemical composition of the essential oil of X. itaficum Moretti from China.

Development and Evaluation of a Loop-mediated Isothermal Amplification(LAMP) Assay for Rapid Detection of Chinese Giant Salamander Ranavirus

Loop-mediated isothermal ampliifcation （LAMP） is a novel nucleic acid diagnostic method that can amplify rapidly a target template under isothermal conditions. In this study, a LAMP assay for rapid detection of Chinese giant salamander ranavirus（CGSRV） was developed from culture isolates and clinical samples. The LAMP assay was developed by designing one set of four speciifc primers, targeting the major capsid protein （MCP） gene of CGSRV. Reaction time and temperature were optimal for 40 min at 62°C. The developed LAMP assay is speciifc and highly sensitive for CGSRV detection, the detection limit could reach about 5 copies of cloned viral genomic fragments. The sensitivity of the LAMP assay was about 1000 and 10-fold higher than that of both conventional and nested PCR, respectively. The LAMP ampliifcation produces a typical ladder-like pattern of products on an agarose gel that can be visually inspected after addition of ethidium bromide. The LAMP assay was evaluated further with clinical samples, and the results indicated the suitability and simplicity of the test as a rapid diagnostic tool for the detection of CGSRV.

Pathological Changes in Andrias davidianus Infected with Chinese Giant Salamander Ranavirus

Chinese giant salamander ranavirus （CGSRV） is an emerging pathogen in captive populations of the Chinese giant salamander （Andrias davidianus）. We processed 140 morbid Chinese giant salamanders from seven captive breeding populations over five years, and describe the disease associated with CGSRV infection. The most common gross signs were significant swelling of the legs and coelomic cavity, erythema of the legs and ventrum in juveniles; cutaneous erosions and ulcerations in adults, particularly the limbs and the head; and marked petechial or ecchymotic hemorrhages of the internal organs, particularly the liver, spleen and kidney. Histological examination showed degeneration, necrosis, and inflammation in many organs, particularly in the organs where hemorrhage was observed. There was evidence of eosinophilic inclusion bodies in degenerated and necrotic cells. We identified virus particles and empty capsids without viral nucleoid in the inclusion bodies using electron microscopy. Virus particles were hexagonal or round shape, and appeared in paracrystalline arrays, aggregates, or singly. All enveloped viral particles were 140-160 nm. Polymerase chain reaction followed by sequencing verified that the virus particles were CGSRV. These results collectively support that CGSRV was the etiologic agent responsible for these mass die-offs of the Chinese giant salamander. The pathology described herein will be useful in diagnosing cases of ranaviral disease caused by CGSRV, and provide evidence that this pathogen is a significant threat to the Chinese giant salamander.

Change of 3 Kinds of Enzyme Activity and Soluble Sugar in 3 Chinese Cabbage Varieties with Different Resistance Level During the Process of Plasmodiophora brassicae Infecting Their Roots

There are different levels of resistance in Chinese cabbage varieties against clubroot.The content of catalase(CAT),peroxidase(POD),phenylalanin ammonia-lyase(PAL),Super Oxide Dismutase(SOD)and soluble sugar activities of 3cultivars with different clubroot-resistant levelswere detected after inoculation in this study.The results suggest that the changing rates of CAT,PAL and SOD contents of resistance cultivars after inoculation were higher than those of susceptible cultivars(Baigengbaiye>Zaobaicaitai>Huangjinxiaobaicai);the POD activities of resistance cultivars reached a peak on an earlier day than those of susceptible cultivars;the increasing rate of soluble sugar of susceptible cultivars was higher than that of the resistance cultivars,and ended with two peaks.Therefore,the four enzymes(CAT,POD,PAL and SOD)and soluble sugar may be used as physiological and biochemical reference indexes for the resistance identification to clubroot after inoculation with P.brassicae.

Phosphine-free synthesis of FeTe2 nanoparticles and self-assembly into tree-like nanoarchitectures

Manipulating the self-assembly of transition metal telluride nanocrystals(NCs) creates opportunities for exploring new properties and device applications. Iron ditelluride(FeTe2) has recently emerged as a new class of magnetic semiconductor with three-dimensional(3D) magnetic ordering and narrow band gap structure, yet the self-assembly of FeTe2 NCs has not been achieved. Herein, the tree-like FeTe2 nanoarchitectures with orthorhombic crystal structure have been successfully synthesized by hot-injection solvent thermal approach using phosphine-free Te precursor. The morphology, size, and crystal structure have been investigated using transmission electron microscopy(TEM), high-resolution TEM(HRTEM),and powder x-ray diffraction(XRD). We study the formation process of tree-like FeTe2 NCs according to trace the change of the sample morphology with the reaction time. It was found that the FeTe2 nanoparticles show oriented aggregation and self-assembly behavior with the increase of reaction time, which is attributed to size-dependent magnetism properties of the samples. The magnetic interaction is thought to be the driving force of nanoparticle self-organization.

Structural stability and vibrational characteristics of CaB6 under high pressure

In situ Raman spectroscopy and x-ray diffraction measurements are used to explore the structural stability of CaB6 at high pressures and room temperature. The results show no evidence of structural phase transitions up to at least 40 GPa.The obtained equation of state with smooth pressure dependencies yields a zero-pressure isothermal bulk modulus B0=170(5) GPa, which agrees well with the previous measurements. The frequency shifts for A1g, Eg, and T2g vibrational modes of polycrystalline CaB6 are obtained with pressure uploading. As the pressure increases, all the vibration modes have smooth monotonic pressure dependence. The Gr¨uneisen parameter of Eg modes is the largest, indicating its largest dependence on the volume of a crystal lattice.

Velocity and Stability of Condensed Polymorphic SiH4: A High-Temperature High-Pressure Brillouin Investigation

Silane(SiH4)is a promising hydrogen-rich compound for pursing high temperature superconducting.Previous high pressure measurements of Raman,x-ray diffraction and theoretical studies on SiH4 mainly focused on its polymorphic structures above 50 GPa,while the structure and the stability under lower pressure range are still unclear.Here we report an investigation of condensed SiH4 by Brillouin scattering measurements at high temperature up to 407 K and high pressure up to 18 GPa.Brillouin scattering frequencies of fluid SiH4 under compression are obtained under isothermal conditions of 300 K,359 K and 407 K.The SiH4 becomes unstable with increasing temperature and subsequently decomposes into silicon and H2.We find that compression at room temperature induces two velocity anomalies corresponding to a fluid-solid state transition and a phaseⅣto phase V transition,respectively.Brillouin scattering spectra has been a powerful tool to investigate the fruitful phases and structure transitions in the hydrogen-rich compound under extreme conditions.

Research Progress and Trends of Domestic Smart Learning Environment

In order to explore the main progress and current status of domestic research on smart learning environment, this paper takes 260 core and CSSCI journal papers included in the CNKI database as the research objects, and uses CiteSpace visual analysis software and uses bibliometrics and knowledge graph analysis as the main research methods, summarizes and analyzes the time distribution of the literature, the distribution of institutions and authors, co-occurrence and clustering of keywords, and research hotspots,etc.

Trichoderma viride F7 improves peanut performances while remediating cadmium-contaminated soil with microplastics

Microplastics(MPs)and cadmium(Cd)in soil have serious negative impacts on plant growth.As a bioremediator,Trichoderma viride may modulate the impacts of MPs and/or Cd on plant growth and heavy metal uptake.In this study,T.viride F7 was used to treat Cd-contaminated soil with and without the presence of polylactic acid MPs to investigate its effects on peanut growth,Cd uptake efficiency,and soil properties.Results showed that F7 increased soil pH,dissolved organic carbon,cation exchange capacity,microbial biomass nitrogen,and microbial biomass carbon,which resulted in increases of 2.10%-19.83%in peanut biomass and mitigated the negative effects of MPs and Cd on peanut growth.Trichoderma viride F7 reduced the soil bioavailable Cd and plant Cd concentrations by 16.68%-34.20%and 5.37%-25.84%,respectively.Regression path analysis showed that F7 could improve peanut performances by altering soil properties and reducing peanut Cd concentrations in MP-Cd-contaminated soil.Soil fungal community analysis indicated that the microbial community was altered via F7 inoculation,which antagonized Fusarium and promoted peanut growth.This study reveals the mechanisms of F7 in mitigating Cd contamination in the soil with the presence of MPs,which provides new ideas for managing MP-heavy metal-contaminated soil and improving soil health.

Fucosyltransferase 8 regulates adult neurogenesis and cognition of mice by modulating the Itga6-PI3K/Akt signaling pathway

Fucosyltransferase 8(Fut8)and core fucosylation play critical roles in regulating various biological processes,including immune response,signal transduction,proteasomal degradation,and energy metabolism.However,the function and underlying mechanism of Fut8 and core fucosylation in regulating adult neurogenesis remains unknown.We have shown that Fut8 and core fucosylation display dynamic features during the differentiation of adult neural stem/progenitor cells(aNSPCs)and postnatal brain development.Fut8 depletion reduces the proliferation of a NSPCs and inhibits neuronal differentiation of aNSPCs in vitro and in vivo,respectively.Additionally,Fut8 deficiency impairs learning and memory in mice.Mechanistically,Fut8 directly interacts with integrinα6(Itga6),an upstream regulator of the PI3kAkt signaling pathway,and catalyzes core fucosylation of Itga6.Deletion of Fut8 enhances the ubiquitination of Itga6 by promoting the binding of ubiquitin ligase Trim21 to Itga6.Low levels of Itga6 inhibit the activity of the PI3K/Akt signaling pathway.Moreover,the Akt agonist SC79 can rescue neurogenic and behavioral deficits caused by Fut8 deficiency.In summary,our study uncovers an essential function of Fut8 and core fucosylation in regulating adult neurogenesis and sheds light on the underlying mechanisms.

A NEW GLOBAL OPTIMIZATION ALGORITHM FOR MIXED-INTEGER QUADRATICALLY CONSTRAINED QUADRATIC FRACTIONAL PROGRAMMING PROBLEM

The mixed-integer quadratically constrained quadratic fractional programming(MIQCQFP)problem often appears in various fields such as engineering practice,management science and network communication.However,most of the solutions to such problems are often designed for their unique circumstances.This paper puts forward a new global optimization algorithm for solving the problem MIQCQFP.We first convert the MIQCQFP into an equivalent generalized bilinear fractional programming(EIGBFP)problem with integer variables.Secondly,we linearly underestimate and linearly overestimate the quadratic functions in the numerator and the denominator respectively,and then give a linear fractional relaxation technique for EIGBFP on the basis of non-negative numerator.After that,combining rectangular adjustment-segmentation technique and midpointsampling strategy with the branch-and-bound procedure,an efficient algorithm for solving MIQCQFP globally is proposed.Finally,a series of test problems are given to illustrate the effectiveness,feasibility and other performance of this algorithm.

High-pressure synthesis of a ternary yttrium-sulfur hydride superconductor with a high T_(c) of approximately 235 K

Ternary hydrides have attracted considerable worldwide attention owing to their potential high-temperature superconducting phases.In contrast to previously reported alloy-based ternary hydrides,we selected the rare earth metal yttrium and light element sulfur to form new yttrium-sulfur hydride superconductors as the target at high pressure,which also linked the two categories of binary clathrate YH_(6) and covalent H_(3)S high-temperature superconductors.The rare earth metal ions served as carrier donors for the dissociation of H_(2) molecules and the formation of clathrate-like cage structures,while the light elements helped stabilize the materials.By applying high-pre ssure and high-temperature conditions,two possible ternary hydride s,i.e.,Im3m-(Y,S)H_(6+δ) and I4/mmm-(Y,S)H_(4+δ),were discovered.Im3m-(Y,S)H_(6+δ) is a ternary hydride with a record superconducting transition temperature(T_(c)) of 235 K belonging to the single-metal hydride system,exhibiting an 11% increment in T_(c) compared with binary Im3m-YH_(6).In the pressure range of 199-249 GPa,the T_(c) of this phase displayed a decreasing tendency but with an apparent slope change,indicating the possible structural distortions or electronic structure changes at 227 GPa.Concurrently,the extrapolated upper critical magnetic field H_(c2) was determined to be 85 T using the Werthamer-Helfand-Hohenberg formula at199 GPa,with a 37% increment compared with Im3m-YH6.The slight volume expansion(~3 %) of Im3m-(Y,S)H_(6+δ) compared with that of binary Im3m-YH_(6) signified the possible interstitial sites of sulfur atoms filling into the hydrogen cages.The size expansion of the center atoms might attract more hydrogen atoms to stabilize the hydrogen cages,contributing to the enhancement of T_(c) and H_(c2) in Im3m-(Y,S)H_(6+δ).The present study demonstrates that introduction of light elements is an effective way for enhancing T_(c) by forming larger hydrogen cages.

TIMP-1 Promotes Expression of MCP-1 and Macrophage Migration by Inducing Fli-1 in Experimental Liver Fibrosis

Background and Aims:Tissue inhibitor of metalloproteinase-1(TIMP-1)plays a role in the excessive generation of extracellular matrix in liver fibrosis.This study aimed to explore the pathways through which TIMP-1 controls monocyte chemoattractant protein-1(MCP-1)expression and promotes hepatic macrophage recruitment.Methods:Liver fibrosis was triggered through carbon tetrachloride,and an adenoassociated virus containing small interfering RNA targeting TIMP-1(siRNA-TIMP-1)was administered to both rats and mice.We assessed the extent of fibrosis and macrophage recruitment.The molecular mechanisms regulating macrophage recruitment by TIMP-1 were investigated through transwell migration assays,luciferase reporter assays,the use of pharmacological modulators,and an analysis of extracellular vesicles(EVs).Results:siRNA-TIMP-1 alleviated carbon tetrachloride-induced liver fibrosis,reducing macrophage migration and MCP-1 expression.Co-culturing macrophages with hepatic stellate cells(HSCs)post-TIMP-1 downregulation inhibited macrophage migration.In siRNATIMP-1-treated HSCs,microRNA-145(miRNA-145)expression increased,while the expression of Friend leukemia virus integration-1(Fli-1)and MCP-1 was inhibited.Downregulation of Fli-1 led to decreased MCP-1 expression,whereas Fli-1 overexpression increased MCP-1 expression within HSCs.Transfection with miRNA-145 mimics reduced the expression of both Fli-1 and MCP-1,while miRNA-145 inhibitors elevated the expression of both Fli-1 and MCP-1 in HSCs.miRNA-145 bound directly to the 3'-UTR of Fli-1,and mi RNA-145-EN-riched EVs secreted by HSCs after TIMP-1 downregulation influenced macrophage recruitment.Conclusions:TIMP-1 induces Fli-1 expression through miRNA-145,subsequently increasing MCP-1 expression and macrophage recruitment.MiRNA-145-enriched EVs from HSCs can transmit biological information and magnify the function of TIMP-1.

Generated genuine tripartite steering and its monogamy in the background of a Kerr-Newman black hole

We study the redistribution of quantum steering and its monogamy in the presence of a four-dimensional Kerr-Newman black hole.The gravitational effect of the Kerr-Newman black hole is shown to generate genuine tripartite steering between causally disconnected regions,depending on the polar angle,angular momentum,electric charge,and magnetic charge of the black hole.We obtain strong evidence of steering monogamy,that is,the"sudden death"of the A→B steering results in the"sudden birth"of B→B steering.We also obtain the condition of maximal steering asymmetry,that is,η0=√1+tanh^(2)(s),revealing the transition between two-way and one-way steering in Kerr-Newman spacetime.

Genetic Approaches for Sex Determination of Chinese Female with Male Pseudohermaphroditism

Male pseudohermaphroditism is a rare disorders of sex development(DSD)that is manifested by a female-like appearance or incompletely differentiated external genitalia in an individual with a Y chromosome.In this paper,we report our investigation of the case of a 33-year-old Chinese female who was diagnosed with a malignant mixed germ-cell tumor of the ovary.To confirm the sex of the female,we utilized genetic approaches to detect amelogenin and Y-STR loci.Y chromosome microdeletion was performed to identify existing deletions in the AZF regions and SRY.Chromosome karyotyping and whole-exome sequencing(WES)were then applied to reveal the deletion of sex chromosome segments and pathogenic variations in DNA sequences.Using DNA-STR genotyping,we detected both AMEL-X and AMEL-Y fragments.We also found haplotype Y-STR loci and detected all alleles.Furthermore,no microdeletion was detected in the AZF regions and SRY.The chromosome karyotyping was 46,XY.WES revealed a transversion mutation of 58T→C in the androgen receptor exon 1,which could be the pathogenic variant in this case of abnormal sexual development.Sex determination in forensic DNA typing is based on the amelogenin system.It is important that forensic biologists should master various genetic approaches to overcome the issue of gender ambiguity caused by DSDs.

Effects of ferrous and manganese ions on anammox process in sequencing batch biofilm reactors

Ferrous and manganese ions, as essential elements, significantly affect the synthesis of Haem-C, which participates in the energy metabolism and proliferation of anammox bacteria. In this study, two identical sequencing batch biofilm reactors were used to investigate the effects of ferrous and manganese ions on nitrogen removal efficiency and the potential of metal ions serving as electron donor/acceptors in the anammox process. Fluorescence in situ hybridization analysis was applied to investigate the microbial growth. Results showed that the nitrogen removal increased at high concentrations of Fe2＋ and Mn2＋ and the maximum removal efficiency was nearly 95% at Fe2＋ 0.08 mmol/L and Mn2＋ 0.05 mmol/L, which is nearly 15% and 8% higher than at the lowest Fe2＋ and Mn2＋ concentrations （0.04 and 0.0125 mmol/L）. The stabilities of the anammox reactor and the anammox bacterial growth were also enhanced with the elevated Fe2＋ and Mn2＋ concentrations. The Fe2＋ and Mn2＋were consumed by anammox bacteria along with the removal of ammonia and nitrite. Stoichiometry analysis showed Fe2＋ could serve as an electron donor for NO3-N in the anammox process. Nitrate could be reduced with Fe2＋ serving as the electron donor in the anammox system, which causes the value of NO^-N/NH4-N to decrease with the increasing of N-removal efficiency.

Isolation and identification of sinapine-degrading bacteria from the intestinal tract of laying hens

This study was aimed to isolate sinapine-degrading bacteria from the intestinal tract of laying hens and to identify the predominant bacteria. Thirty-week old healthy laying hens were killed, and the chyme in the digestive tract was inoculated into modified Czapek medium containing sinapin and cultivated at 37 ℃for 10 days. The optical density(OD) values of the bacterial solutions at different cultivating times were detected by a spectrophotometric method. The predominant strains were identified by 16 S rRNA gene analysis. We extracted the extracellular products of the predominant strains to determine the total protein using the Coomassie brilliant blue method, and to determine the activities of some extracellular enzymes using the agar plate diffusion method. Nine strains were isolated from the lower intestinal tract of laying hens. Among the 9 strains, 5 were from the ileum, 2 were from the ceca and 2 were from the jejunum. We could not isolate any strains from the upper intestinal tract, such as the stomach and duodenum. Eight of those 9 isolated strains were gram negative and one was gram positive. Strains YD-1 and YD-2 were better than other strains in their abilities to degrade sinapine. Strains YD-1 and YD-2 were identified as Escherichia coli and Klebsiella spp., respectively, by the 16 S rRNA sequence analysis.The total protein level of the extracellular products was 1.213 g/L for YD-1 and 1.990 g/L for YD-2. Both extracellular products of YD-1 and YD-2 had the activities of protease, amylase and urease. This study confirmed that the primary site of sinapine degradation is in the lower intestinal tract of laying hens. The sinapine-degrading strains are mainly gram negative. Strains YD-1 and YD-2 are predominant in degrading sinapine and they belong to E. coli and Klebsiella spp., respectively. Both extracellular products of YD-1 and YD-2 contain protease, amylase and urease. Strain YD-2 is better than strain YD-1 in its ability to degrade sinapine.