APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
·
2023
·Vol. 107
·期 11
·3745-3761
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IF 5
Xu Chenglong,Lin Wenxi,Chen Yunni,Gao Boliang,Zhang Zhibin,Zhu Du
Perylenequinones (PQs) are a class of natural polyketides used as photodynamic therapeutics. Heat stress (HS) is an important environmental factor affecting secondary metabolism of fungi. This study investigated the effects of HS treatment on PQs biosynthesis of Shiraia sp. Slf14(w) and the underlying molecular mechanism. After the optimization of HS treatment conditions, the total PQs amount reached 577 ± 34.56 mg/L, which was 20.89-fold improvement over the control. Also, HS treatment stimulated the formation of intracellular nitric oxide (NO). Genome-wide analysis of Shiraia sp. Slf14(w) revealed iNOSL and cNOSL encoding inducible and constitutive NOS-like proteins (iNOSL and cNOSL), respectively. Cloned iNOSL in Escherichia coli BL21 showed higher nitric oxide synthase (NOS) activity than cNOSL, and the expression level of iNOSL under HS treatment was observably higher than that of cNOSL , suggesting that iNOSL is more responsible for NO production in the HS-treated strain Slf14(w) and may play an important role in regulating PQs biosynthesis. Moreover, the putative biosynthetic gene clusters for PQs and genes encoding iNOSL and nitrate reductase (NR) in the HS-treated strain Slf14(w) were obviously upregulated. PQs biosynthesis and efflux stimulated by HS treatment were significantly inhibited upon the addition of NO scavenger, NOS inhibitor, and NR inhibitor, indicating that HS-induced NO, as a signaling molecule, triggered promoted PQs biosynthesis and efflux. Our results provide an effective strategy for PQs production and contribute to the understanding of heat shock signal transduction studies of other fungi.
Key points
• PQs titer of Shiraia sp. Slf14(w) was significantly enhanced by HS treatment . • HS-induced NO was first reported to participate in PQs biosynthetic regulation . • Novel inducible and constitutive NOS-like proteins (iNOSL and cNOSL) were obtained and their NOS activities were determined .
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INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
·
2023
·
IF 3.6
Yanan Wang,Man Wang,Honghong Sun,Kangyao Tang,Xiaoli Xi,Zuoren Nie
Oxide dispersion strengthened tungsten (ODS-W) alloys are promising plasma facing material in future fusion reactors. In this study, composite powders of W-Er 2 O 3 were prepared by co-deposition method and hydrogen reduction, and then consolidated by spark plasma sintering (SPS). Microstructure evolution during co-deposition process was investigated using X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and Fourier transform infrared spectrometer (FTIR). Also, simulation using DMol3 module in Materials Studio was carried out to understand the co-deposition mechanism. The results showed that H + of W-OH bond in white tungstic acid was replaced by Er 3+ due to coordination reaction during co-deposition process, leading to formation of ring-like chelate of (WO) n Er. This indicates that doping of Er 3+ was achieved at a molecular level. Consequently, Er 2 O 3 particles were relatively uniformly distributed in W-Er 2 O 3 alloy, and the hardness and compressive strength reached 627 ± 19 HV and 1640 ± 40 MPa, respectively.
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Science China-Materials
·
2023
·Vol. 66
·期 8
·3213-3222
·
IF 8.1
Wen Zihao,Meng Hong,Jiang Shengda,Tang Zhongyu,Liu Yiwen,Chu Yanhui
Developing superior oxidation resistance of high-entropy diborides is critical for extending their potential applications in harsh environments. Herein, we developed non-equimolar (Hf,Zr,Ta,W)B 2 high-entropy diborides with superior oxidation resistance by adjusting W contents for the first time. The as-fabricated (Hf 0.28 Zr 0.28 Ta 0.28 W 0.15 )B 2 samples are predicted to possess superior oxidation resistance at 1473–1773 K through the oxidation depth quantitative analysis obtained by machine learning, which is attributed to the reason that the moderate WO 3 can effectively inhibit the volatilization of B 2 O 3 . Furthermore, a four-layered structure is found in the generated product layers at 1773 K, which is due to the preferential oxidation of Hf and Zr elements at low oxygen partial pressure and the different diffusion activation energies of oxide products. The preferential oxidation of Hf and Zr elements is further demonstrated by the computational phase stability diagrams, and oxygen adsorption energies and charge transfer between oxygen atoms and different metal adsorption sites via first-principles calculations. Such superior performance endows (Hf 0.28 Zr 0.28 Ta 0.28 W 0.15 )B 2 with potential applications as ultrahigh-temperature structural materials.
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Nanoscale
·
2022
·Vol. 14
·期 13
·5002-5009
·
IF 8.307
Tiantian Dai,Zanhong Deng,Shimao Wang,Xiaodong Fang,Gang Meng
With features of innate tunnels and oxygen vacancies derived from a unique geometrical structure and sub-stoichiometric compositions, W18O49 nanowires have been explored as multifunctional materials with diverse applications. Though thermal oxidation offers a facile method to synthesize patterned W18O49 nanowires, the relatively high growth temperature (≳500 °C) hinders their emerging applications in flexible or wearable electronics. In this work, aiming to lower the growth temperature of W18O49 nanowires by thermal oxidation, the temperature and oxygen partial pressure dependent growth has been systematically investigated for both W films and powders. W18O49 nanowires could be steadily obtained with appropriate temperature and oxygen pressure ranges for both cases, while the growth temperature of a W film (metastable β phase dominant) could be much lower than that of W powder (α phase). The structural analysis indicates that metastable β-W is susceptible to oxidation in comparison with α-W and thus generates oxidation-induced chemical compression for nanowire growth. The growth temperature of W18O49 nanowires could be reduced to ca. 400 °C, which paves the way for the in situ patterning of W18O49 nanowires on indium-tin-oxide (ITO) glass substrates and flexible substrates.
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ACS Sensors
·
2022
·
IF 9.618
Xiafen Hu,Xiang Li,Huimin Yang,Chengjia Xu,Weiqiang Xiong,Xiang Guo,Changsheng Xie,Dawen Zeng
Defect engineering has received extensive attention as an effective method to tune the gas sensing properties of semiconductor materials. Here, defective WO3 (D-WO3) nanosheets were obtained by a simple hydrogenation process with a detection limit as low as 5 ppb for dimethyl trisulfide (DMTS) and a response of 2.3 times that of the initial WO3 nanosheets to 100 ppb DMTS. Importantly, X-ray photoelectron spectroscopy and Raman spectroscopy confirmed the partial loss of oxygen atoms in D-WO3 nanosheets, and density functional theory calculations found that the W sites near the oxygen defect showed higher adsorption energy for DMTS and transferred more electrons during the gas interaction, indicating that the active W site caused by oxygen atom loss can effectively enhance the reactivity of two-dimensional WO3 nanosheets. Different from the traditional oxygen defect model, this work reveals the positive effect of active metal sites on gas sensing for the first time, which is expected to provide an effective reference for the sensing application of defect engineering in metal oxides.
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JOURNAL OF LUMINESCENCE
·
2021
·
IF 3.599
Xuemei Yao,Yifan Zhong,Junzhi Che,Jun Chen,Fanhua Zeng,Bin Deng,Ruijin Yu
Red phosphor based on Sm 3+ has a high potential application in displays and lighting. In this work, novel reddish-orange emitting phosphors were obtained by introduced Sm 3+ into the double-perovskite structure Sr 3 TeO 6 host lattice by solid-state reaction method. The phase composition and optical properties were discussed in detail. Through the X-ray diffraction (XRD) and Rietveld refinement analysis, the prepared Sr 3 TeO 6 :Sm 3+ phosphors presented the triclinic symmetry with the and space group Fm3m . The photoluminescent spectra reveal that The Sr 3 TeO 6 :Sm 3+ phosphors emit intense reddish-orange emission light at 652 nm ascribed to the 4 G 5/2 - 6 H 9/2 transition. Furthermore, the correlated color temperature (CCT) and color purity of Sr 3 TeO 6 : x Sm 3+ (0.01 ≤ x ≤ 0.30) are calculated using emission spectra . The optimum doped concentration is 2 mol%. The luminescence intensity remained at 87% at 480 K of its original value at 300 k. The red light-emitting diode (LED) is successfully fabricated based on Sr 3 TeO 6 :0.02Sm 3+ samples. The CIE coordinates of the fabricated white LED nearly overlaps with an equal energy point (0.333, 0.333) in the CIE 1931 color system. All results indicate that the Sr 3 TeO 6 :Sm 3+ phosphors can be applied in the white light-emitting diodes (W-LEDs) field.
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JOURNAL OF MATERIALS SCIENCE
·
2021
·Vol. 56
·期 34
·19155-19164
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IF 4.22
Fan Xuhui,Wang Jing,Rao Yu,Zhao Lei,Zhu Kongjun
Dielectric ceramics have attracted ever-increasing interest in energy storage applications due to their high-power density and fast charge–discharge speed. In particular, AgNbO 3 -based antiferroelectric ceramics are considered potential substitutes for lead-based ceramics. AgNbO 3 ceramics sintered with fine hydrothermal-synthesized powders show the advantage of high breakdown strength. However, the fine grains lead to the decreased polarization, which harms the recoverable energy density. In this work, a little amount over-stoichiometrical WO 3 and MnO 2 were introduced to synergistically improve the polarization and dielectric breakdown strength of obtained AgNbO 3 ceramics. The dependences of structures and dielectric properties on WO 3 doping were explored. A maximum polarization of 49.4 μC/cm 2 and E b as large as 285 kV/cm were achieved in 0.1 wt % WO 3 and MnO 2 co-doped AgNbO 3 ceramic. The corresponding W rec reached 2.75 J/cm 3 , which was 1.3 times larger than that of pristine AgNbO 3 ceramics. Moreover, benign thermal stability with W rec = 2.2–2.7 J/cm 3 over 30–150 °C at 240 kV cm −1 was also achieved in 0.1 wt.% WO 3 and MnO 2 co-doped AgNbO 3 ceramics.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2020
·
IF 5.162
Lei Wang,Yujie Li,Dong Xiang,Weimin Zhang,Xinpeng Bai
Lutein is a hydrophobic carotenoid with diverse bioactivities. For encapsulating the molecule in a novel method, we prepared two emulsions from xanthan and propylene glycol alginate at the ratios of 3:7 and 4:6. The instability index and particle size of the emulsions were determined using a stability analyzer and laser particle size analyzer. The influence of crystallization on the emulsions was observed under a polarizing microscope. The effects of centrifugal force and storage on the lutein emulsions were analyzed by measuring the changes in absorbance. The results showed that the emulsion fabricated by xanthan and propylene glycol alginate at the ratio of 4:6 was highly stable, and crystals were dispersed when xanthan and propylene glycol alginate existed. These results revealed that the hydrophobicity and absorption kinetics of emulsifiers would determine the stability of emulsion when the viscosity of emulsifiers reached a certain value, and the stability of emulsions would affect the stability of lutein in the emulsions.
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COLLOIDS AND SURFACES B-BIOINTERFACES
·
2022
·
IF 5.999
Qingqing Li,Xinyu Fan,Xiaohan Pan,Ying Yu,Lingyan Jian,Yu Zhang,Tian Yin,Haibing He,Xing Tang,Jian Jin,Jingxin Gou
The intramuscular administration of long-acting injectable microparticles elicits a local macrophage uptake resulting in decreased bioavailability. Herein, we developed a ginkgolide B (GB) loaded Solid/Oil/Water (S/O/W) solid lipid microparticles (SLMs) which were modified by hydroxyethyl starch (HES) or poly(ethylene glycol) (PEG) with different surface densities to investigate the influence of surface properties on the cellular uptake and systemic drug exposure. The spherical SLMs with a mean particle size of 10 µm were prepared by melt emulsification and post-insertion method, showing controlled release profile with less than 10 % of GB released in first 2 h. HES-SLMs resulted in lowest degree of RAW264.7 macrophage uptake in vitro and a higher systemic drug exposure in rats than PEG coating SLMs, indicting the capability of thick HES layer of SLMs in evading cellular uptake and sustained GB release. Overall, HES modified SLMs possess a great potential as intramuscular injected drug delivery system to improved bioavailability.
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SEPARATION SCIENCE AND TECHNOLOGY
·
2025
·
IF 2.3
Shijie Tang,Jiaxue Li,Hailin Yang,Ming Duan,Shenwen Fang
This study evaluated the thermal and electrical dehydration performance of eight polyether amines with varying molecular weights and HLB values for W/O crude oil emulsion breaking before and after alkylation modification. The experimental results demonstrated that the dehydration rates of polyether amine both before and after modification were less than 30%. However, all polyether amines can enhance the electrical dehydration rate, with the modified polyether amines having higher dehydration rate. Specifically, the modified polyether amine P20-H2.8 achieved a dehydration rate of 64.29% under conditions of 4 kV, 60°C, and a dosage of 200 mg/L, which is 2.25 times higher than that without any chemical agent addition. Interfacial property studies revealed that the modified polyether amines exhibited superior interfacial activity and stronger ability to reduce the elastic modulus of the oil-water interface under the electric field, thereby contributing to their better demulsification performance. Nevertheless, the electrical dehydration rate of the modified polyether amine P20-H2.8 was still much lower than that of conventional block polyether demulsifier, indicating a need for further improvement in interfacial activity. Although the research results of polyether amines are not very good, it expands the research direction of demulsifiers and provides some new insights for demulsifier development.
研究领域:
石油工程
·
胶体与界面科学
·
高分子化学改性
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JOURNAL OF POWER SOURCES
·
2025
·
IF 7.9
Chen-Cheng Wan,Yan-An Li,Shan-Lin Zhang,Yuan Gao,Muhammad Bilal Hanif,Cheng-Xin Li
Traditionally, Ni-based cermet fuel electrodes have been extensively utilized in solid oxide electrolysis cells (SOECs) owing to their excellent conductivity and electrochemical catalytic activity. However, the development of alternative materials has gained attention due to concerns over Ni's susceptibility to carbon deposition and long-term stability issues. In the present study, we design W-doped Sr 0.9 Fe 0.67 Ti 0.3-x Co 0.03 O 3-δ (SFTCW, x = 0.01) as a novel hydrogen electrode material for SOECs. The results reveal that W doping promotes the precipitation of bimetallic Co-Fe alloy, thereby increasing the active sites within the material and preserves the original structure. In a reducing atmosphere, SFTCW demonstrates superior performance compared to SFTC in both Sc 2 O 3 stabilized ZrO 2-δ (ScSZ) and La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O 3-δ (LSGM)-electrolyte supported cells. LSGM-based cells exhibit superior performance, 5 times higher than ScSZ-based cells, achieving an electrolysis current density of ∼1000 mA cm −2 and demonstrating considerable stability for up to 122 h, indicating the potential application of SFTCW for solid oxide electrolysis cells.
研究领域:
材料科学
·
电化学
·
能源工程
·
无机非金属材料
·
催化化学
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METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
·
2019
·Vol. 50
·期 10
·4827-4838
·
IF 1.985
Liu Jun-Kai,Zhang Guo-Hua,Sun Guo-Dong
We propose a process to produce ultrafine W-10 wt pct Cu composite powders by reducing the mixtures of copper tungstate (CuWO 4 ) and tungsten trioxide (WO 3 ) (from the calcination of a mixture of ammonium paratungstate and copper nitrate trihydrate) with carbon black and hydrogen. First, ultrafine pre-reduced tungsten-copper (W-Cu) powders containing a small amount of WO 2 were produced by reducing mixtures of CuWO 4 and WO 3 with insufficient carbon black; then the obtained products were further reduced by hydrogen to remove the residual oxygen. This method provides a simple and low-cost route to prepare ultrafine W-10 wt pct Cu composite powders. The composite powders were sintered at different temperatures [1323 K (1050 °C), 1373 K (1100 °C), 1423 K (1150 °C), 1473 K (1200 °C), and 1523 K (1250 °C)] for 3 hours. A maximum densification of the obtained compact was achieved at a sintering temperature of 1523 K (1250 °C), with a relative density, Vickers hardness and thermal conductivity of the W-10 wt pct Cu composites of 97.8 pct, 365 HV and 165 W/m K, respectively.
研究领域:
材料科学
·
冶金工程
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