29 research outputs found

    Characterization and genomic analysis of a lytic Stenotrophomonas maltophilia short-tailed phage A1432 revealed a new genus of the family Mesyanzhinovviridae

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    Stenotrophomonas maltophilia (S. maltophilia) is an emerging opportunistic pathogen that exhibits resistant to a majority of commonly used antibiotics. Phages have the potential to serve as an alternative treatment for S. maltophilia infections. In this study, a lytic phage, A1432, infecting S. maltophilia YCR3A-1, was isolated and characterized from a karst cave. Transmission electron microscopy revealed that phage A1432 possesses an icosahedral head and a shorter tail. Phage A1432 demonstrated a narrow host range, with an optimal multiplicity of infection of 0.1. The one-step growth curve indicated a latent time of 10 min, a lysis period of 90 min, a burst size of 43.2 plaque-forming units per cell. In vitro bacteriolytic activity test showed that phage A1432 was capable to inhibit the growth of S. maltophilia YCR3A-1 in an MOI-dependent manner after 2 h of co-culture. BLASTn analysis showed that phage A1432 genome shares the highest similarity (81.46%) with Xanthomonas phage Xoo-sp2 in the NCBI database, while the query coverage was only 37%. The phage contains double-stranded DNA with a genome length of 61,660 bp and a GC content of 61.92%. It is predicted to have 79 open reading frames and one tRNA, with no virulence or antibiotic resistance genes. Phylogenetic analysis using terminase large subunit and DNA polymerase indicated that phage A1432 clustered with members of the Bradleyvirinae subfamily but diverged into a distinct branch. Further phylogenetic comparison analysis using Average Nucleotide Identity, proteomic phylogenetic analysis, genomic network analysis confirmed that phage A1432 belongs to a novel genus within the Bradleyvirinae subfamily, Mesyanzhinovviridae family. Additionally, phylogenetic analysis of the so far isolated S. maltophilia phages revealed significant genetic diversity among these phages. The results of this research will contribute valuable information for further studies on their morphological and genetic diversity, will aid in elucidating the evolutionary mechanisms that give rise to them

    Challenges in QCD matter physics - The Compressed Baryonic Matter experiment at FAIR

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    Substantial experimental and theoretical efforts worldwide are devoted to explore the phase diagram of strongly interacting matter. At LHC and top RHIC energies, QCD matter is studied at very high temperatures and nearly vanishing net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was created at experiments at RHIC and LHC. The transition from the QGP back to the hadron gas is found to be a smooth cross over. For larger net-baryon densities and lower temperatures, it is expected that the QCD phase diagram exhibits a rich structure, such as a first-order phase transition between hadronic and partonic matter which terminates in a critical point, or exotic phases like quarkyonic matter. The discovery of these landmarks would be a breakthrough in our understanding of the strong interaction and is therefore in the focus of various high-energy heavy-ion research programs. The Compressed Baryonic Matter (CBM) experiment at FAIR will play a unique role in the exploration of the QCD phase diagram in the region of high net-baryon densities, because it is designed to run at unprecedented interaction rates. High-rate operation is the key prerequisite for high-precision measurements of multi-differential observables and of rare diagnostic probes which are sensitive to the dense phase of the nuclear fireball. The goal of the CBM experiment at SIS100 (sqrt(s_NN) = 2.7 - 4.9 GeV) is to discover fundamental properties of QCD matter: the phase structure at large baryon-chemical potentials (mu_B > 500 MeV), effects of chiral symmetry, and the equation-of-state at high density as it is expected to occur in the core of neutron stars. In this article, we review the motivation for and the physics programme of CBM, including activities before the start of data taking in 2022, in the context of the worldwide efforts to explore high-density QCD matter.Comment: 15 pages, 11 figures. Published in European Physical Journal

    Alleviation of seeding chlorosis by plant growth regulators in drip-irrigated rice

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    Drip irrigation can produce high rice yields with significant water savings; therefore, it extends rapidly in water-scarce northern China. However, drip-irrigated rice seedlings often exhibit Fe chlorosis. The objective of this field experiment was thus to determine the ability of plant growth regulators to alleviate chlorosis in drip-irrigated rice seedlings. The study compared three plant growth regulators (1-naphthylacetic acid, NAA; sodium nitrophenolate, CSN; and diethyl aminoethyl hexanoate, DA-6) applied in two ways (seed-soaking and drip-application). The results showed that CSN increased root oxidation activity by 37% in the seed-soaking treatment and by 45% in the soil-application treatment. Seed soaking with NAA, CSN, and DA-6 increased the active Fe content in leaves by 8.8%, 17.5%, and 11.4%, respectively, compared with untreated seedlings. Iron absorption and SPAD values were both greater in the soil-application plots than in the seed-soaking plots. Among the plant growth regulators, CSN resulted in the highest yield (2.2% greater than untreated rice in the seed-soaking treatment and 12.8% greater than untreated rice in the soil-application treatment). In conclusion, CSN significantly improved root Fe uptake at the seedling stage and reduced chlorosis in drip-irrigated rice. Therefore, CSN drip application can be recommended for alleviating rice chlorosis in practical use

    Effects of salinity and nitrogen on cotton growth in arid environment

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    The influences of different N fertilization rates and soil salinity levels on the growth and nitrogen uptake of cotton was evaluated with a pot experiment under greenhouse conditions. Results showed that cotton growth measured as plant height was significantly affected by the soil salinity and N-salinity interaction, but not by N alone. Cotton was more sensitive to salinity during the emergence and early growth stages than the later developmental stages. At low to moderate soil salinity, the growth inhibition could be alleviated by fertilizer application. Soil salinity was a dominated factor affecting cotton’s above-ground dry mass and root development. Dry mass of seed was reduced by 22%, 52%, and 84% respectively, when the soil salinity level increased from control level of 2.4 dS m−1 to 7.7 dS m−1, 12.5 dS m−1 and to 17.1 dS m−1, respectively. N uptake increased with N fertilization at adequate rates at both low and medium soil salinities but was not influenced by over N fertilization. At higher salinities, N uptake was independent of N rates and mainly influenced by soil salinity. The uptake of K decreased with soil salinity. The concentration of Na, Cl and Ca in plant tissues increased with soil salinity with highest concentrations in the cotton leaf

    Evaluating salinity distribution in soil irrigated with saline water in arid regions of northwest China

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    In arid and semi-arid regions, salinity is a serious and chronic problem for agriculture. A 3-year field experiment in the arid environment of Xinjiang, northwest China, was conducted to study the salinity change in soil resulting from deficit irrigation of cotton with non-saline, moderate saline and high saline water. The salinity profile distribution was also evaluated by an integrated water, salinity, and nitrogen model, ENVIRO-GRO. The simulated and observed salinity distributions matched well. Results indicated that after 3 years of cotton production, the average salinity in the 1.0-m soil profile was 336% and 547% of the original soil profile, respectively, for moderate saline and high saline water irrigation. If the practices continued, the average soil salinity (ECe) in the 1.0-m soil profile would approach a steady level of 1.7, 10.8, and 14.7 dS m-1, respectively, for the treatments receiving irrigation waters of 0.33, 3.62, and 6.71 dS m-1. It was concluded that deficit irrigation of saline water in this region was not sustainable. Model simulation showed that a big flood irrigation after harvest can significantly reduce the salt accumulation in the soil profile, and that this practice was much more efficient for salinity control than applying the same extra amount of water during the growing season.Irrigation management Soil salinity Model

    Ammonium alleviates iron deficiency of drip-irrigated rice seedlings in low soil temperature in calcareous soil

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    Paddy rice (Oryza sativa L.) is easy to suffer from iron (Fe) deficiency in drip-irrigated (DI) calcareous soils, especially at the seedling stage. Low soil temperature and the soil nitrogen (N) is dominated by nitrate (NO3{\rm NO}_3^-) is probably the reason of Fe chlorosis in this stage. The objective of this experiment was to elucidate the causes of Fe deficiency induced by low soil temperature and the mechanism of ammonium (NH4+{\rm NH}_4^ +) alleviate Fe deficiency of DI rice. Applying different N forms (NH4+{\rm NH}_4^ + or NO3{\rm NO}_3^-) to two rice cultivars (cv. ‘T43’ and ‘T04’, Fe-efficient and Fe-inefficient genotype, respectively) under different soil temperatures to study the growth and Fe uptake of DI rice. The results showed that low soil temperature reduced the root biomass and root activity of rice significantly, which in turn, resulted in low leaf SPAD value and Fe uptake of rice. The rice fed with NH4+{\rm NH}_4^ + had improved root activity and bigger root surface area, higher rhizosphere soil DTPA-Fe concentration and more Fe uptake than fed with NO3{\rm NO}_3^- under low soil temperature. The results indicated NH4+{\rm NH}_4^ + alleviates Fe deficiency of DI rice by improving the availability of rhizosphere soil Fe, increasing the root surface area and root activity. Application of NH4+N{\rm NH}_4^ + -{\rm N} to DI rice is a promise agronomic measure to alleviate Fe deficiency

    Dynamics of ammonia-oxidizing archaea and bacteria in relation to nitrification along simulated dissolved oxygen gradient in sediment-water interface of the Jiulong river estuarine wetland, China

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    Dissolved oxygen (DO) is a very important factor controlling the nitrogen cycle in wetlands. However, it is still unclear to what extent the presence of ammonia-oxidizing archaea (AOA) and bacteria (AOB), and related nitrification, are influenced by DO in estuarine wetlands. The aims of this study were to determine changes of nitrification at the sediment-water interface, to examine the abundance and diversity of archaeal and bacterial ammonia oxidizers in estuarine sediments, and to identify the correlation between nitrification and ammonia-oxidizing microorganisms along a simulated dissolved oxygen gradient in a Chinese estuarine wetland. The results showed that the nitrification rate was positively correlated with the diversity and abundance of AOA but not AOB, and the abundance and diversity of AOA can explain 87 % of the total variance of the first axes in the redundancy analysis. This indicates that AOA were primarily involved in ammonia oxidation in this study. Additionally, AOB were much more influenced by DO than AOA inferred from the assessment of dominant species and principal coordinates analysis of AOA and AOB. Higher diversity and abundance of AOA occurred in the mangrove sediments, which explain the higher nitrification rates in the mangrove sediments compared to the bare mudflat sediments. Notably, the trend of nitrification rate in the bare mudflat sediments was different from that in the mangrove sediments, suggesting that the extent of nitrification as impacted by DO depends largely on the sediment biotic and nutrient properties, and its environmental conditions including DO levels

    Soil Nitrogen Distribution Affects Nitrogen Utilization and Yield of Drip-Irrigated Rice

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    The cultivation of drip-irrigated rice has resulted in lower yields. However, the decrease in rice yield under drip irrigation and its relationship with the existing water and N regime have not been fully explained. Research and development of optimized water and N-management techniques are crucial for increasing rice yield under drip irrigation. In this study, two irrigation treatments were set: conventional drip irrigation (DIO) and drip irrigation with water stress (DIS). Each irrigation treatment contained four N rates: urea N 240 kg ha−1 (LN), urea N 300 kg ha−1 (MN), urea N 360 kg ha−1 (HN), and ammonium sulfate N 300 kg ha−1 (AN). The soil’s ammonium and nitrate contents were measured on the 2nd and 28th days after N application at panicle initiation stage. At anthesis, the aboveground and root biomass of rice were measured. In heading and maturity stage the N content of aboveground was measured and the yield, yield components, and NPFP were assessed at maturity stage. The results showed the following: (1) On the second day after N application, the contents of soil NO3−-N and NH4+-N in the 0–10 cm soil layer were highest for both the DIO and DIS. On the 28th day after N application, the soil NO3−-N content was highest at the 20–40 cm depth, while the soil NH4+-N content was still highest at the 0–10 cm depth. (2) The aboveground and root biomass in DIO treatment were significantly higher than in DIS. Furthermore, the root biomass at the 0–10 cm depth was significantly greater than at the 10–50 cm depth for both the DIO and DIS treatments. In the DIO treatment, the root biomass at the 10–50 cm depth was significantly higher with the HN and AN treatments compared to MN. However, in the DIS treatment, the root biomass at the 10–50 cm depth did not show significant differences between the MN, HN, and AN. (3) N accumulation in rice was significantly higher for the DIO treatment compared to the DIS treatment. Under the same irrigation treatment, the N accumulation in rice was highest in the AN and lowest in the LN. The PrNTA and PrNTC in DIS were significantly higher than in DIO, while the PoNAA and PoNAC were significantly lower in DIS. (4) The number of panicles, spikelets per panicle, seed-setting rate, 1000-grain weight, and grain yield were significantly lower in DIS. Under the DIS, these parameters were not significantly different among the MN, HN, and AN. In the DIO, the seed-setting rate, 1000-grain weight, and yield were not significantly different between the HN and AN, but were significantly higher than in the MN and LN. (5) NPFP was significantly higher in the DIO compared to the DIS. Among the different N rates, NPFP was highest with the AN treatment and lowest with the LN. In summary, under drip irrigation, there was a mismatch between soil mineral N and the distribution of rice roots, leading to reduced N accumulation and utilization in rice, ultimately impacting yield formation. Increasing N application and soil ammonium nutrition can improve rice yield under drip irrigation. However, optimizing N fertilizer management may not increase rice yield further when irrigation is further limited

    Acidic compost tea enhances phosphorus availability and cotton yield in calcareous soils by decreasing soil pH

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    The long-term application of chemical fertilisers in calcareous soil causes the stable P in soil to accumulate and not be effectively utilised. In this study, whether acidic compost tea (CT) could increase the available P in calcareous soil was evaluated through a pot experiment. The P forms of the samples were analysed using Hedley sequential P fractionation. CT had significant effects on different soil P fractions and P uptake (p < 0.05). Compared with organic fertiliser (OF), acidic CT increased the availability of H2O-P and NaHCO3-P by 15.9% and 12.6%, respectively, it mainly comes from the dissolution of HCl-P and residue-P. CT also promoted the growth and yield of cotton and significantly increased P use efficiency by 13.8% and 31.6% (p < 0.05), respectively, compared with OF, because the H+ in CT reduced the pH of the calcareous soil, promoted the dissolution of stable P in soil, and reduced the fixation of P from the fertiliser. However, the organic matter in CT did not contribute much to the desorption of P. These findings provide a new idea for the activation and utilisation of P in calcareous soil

    Recent Progresses and Development of Advanced Atomic Layer Deposition towards High-Performance Li-Ion Batteries

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    Electrode materials and electrolytes play a vital role in device-level performance of rechargeable Li-ion batteries (LIBs). However, electrode structure/component degeneration and electrode-electrolyte sur-/interface evolution are identified as the most crucial obstacles in practical applications. Thanks to its congenital advantages, atomic layer deposition (ALD) methodology has attracted enormous attention in advanced LIBs. This review mainly focuses upon the up-to-date progress and development of the ALD in high-performance LIBs. The significant roles of the ALD in rational design and fabrication of multi-dimensional nanostructured electrode materials, and finely tailoring electrode-electrolyte sur-/interfaces are comprehensively highlighted. Furthermore, we clearly envision that this contribution will motivate more extensive and insightful studies in the ALD to considerably improve Li-storage behaviors. Future trends and prospects to further develop advanced ALD nanotechnology in next-generation LIBs were also presented
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