Frontiers in Microbiology
·
2019
·
IF 4.259
Kang Yajing,Wang Yingying,Hou Bingbing,Wang Ruida,Ye Jiang,Zhu Xiaoyu,Wu Haizhen,Zhang Huizhan
Lincomycin is one of the most important antibiotics in clinical practice. To further understand the regulatory mechanism on lincomycin biosynthesis, we investigated a pleiotropic transcriptional regulator AdpAlin in the lincomycin producer Streptomyces lincolnensis NRRL 2936. Deletion of adpAlin (which generated ΔadpAlin) interrupted lincomycin biosynthesis and impaired the morphological differentiation. We also found that putative AdpA binding sites were unusually scattered in the promoters of all the 8 putative operons in the lincomycin biosynthetic gene cluster (BGC). In ΔadpAlin, transcript levels of structural genes in 8 putative operons were decreased with varying degrees, and electrophoretic mobility shift assays (EMSAs) confirmed that AdpAlin activated the overall putative operons via directly binding to their promoter regions. Thus, we speculated that the entire lincomycin biosynthesis is under the control of AdpAlin. Besides, AdpAlin participated in lincomycin biosynthesis by binding to the promoter of lmbU which encoded a cluster sited regulator (CSR) LmbU of lincomycin biosynthesis. Results of qRT-PCR and catechol dioxygenase activity assay showed that AdpAlin activated the transcription of lmbU. In addition, AdpAlin activated the transcription of the bldA by binding to its promoter, suggesting that AdpAlin indirectly participated in lincomycin biosynthesis and morphological differentiation. Uncommon but understandable, AdpAlin auto-activated its own transcription via binding to its own promoter region. In conclusion, we provided a molecular mechanism around the effect of AdpAlin on lincomycin biosynthesis in S. lincolnensis, and revealed a cascade regulation of lincomycin biosynthesis by AdpAlin, LmbU, and BldA.
研究领域:
微生物学
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分子生物学
·
抗生素研究
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产品关联
DOI
PubMed
高影响因子
OPTICS EXPRESS
·
2025
·Vol. 33
·期 6
·13895-13906
·
IF 3.3
Xiaoxiao Chen,Xueguang Lu,Lu Tang,Kefan Chen,Wanxia Huang
Despite striking advances in terahertz (THz) sources and detectors, the exploitation of active materials that can alter their properties in response to external excitations for the manipulation of THz waves is another major issue. Here, freestanding and easily scalable composite film based on vanadium dioxide/carboxymethyl cellulose (VO2/CMC) is proposed to realize thermally and optically tunable THz waves. This VO2/CMC composite film exhibits broadband modulation with a modulation depth of up to 76%, a response time of about 1.2 s and high stability both in mechanical deformation and in air. Based on the above VO2/CMC composite film, a THz metamaterial with absorption-reflection switchability is demonstrated. By controlling the temperature-dependent phase transition of VO2 particles, the reflection dip of the metamaterial at 0.423 THz with an amplitude of -25 dB first shifts to lower frequencies accompanied by an increase in amplitude, and finally disappears with the THz metamaterial reflecting THz waves almost completely. The experimental results agree well with numerical simulations and the modulation mechanism of the metamaterial is also investigated. This work provides a simple and low-cost method for developing VO2-based THz multifunctional smart devices with promising applications in areas such as but not limited to THz modulators and sensors.
研究领域:
材料科学
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光学工程
·
太赫兹技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Energy Storage
·
2023
·
IF 9.4
Min Li,Fan Luo,Xianghui Liang,Shuangfeng Wang,Xuenong Gao,Zhengguo Zhang,Yutang Fang
Building materials with the dual function of temperature and humidity regulation can improve people's living comfort and reduce energy consumption. In this work, a simple and convenient strategy for building a comfortable indoor temperature and humidity environment was proposed. The phase change humidity control material (PCHCM) was prepared by the mixing of form-stable composite phase change material (CPCM) as temperature-control component and hygroscopic MIL-100(Fe) as humidity-control component. In PCHCM, the CPCM was obtained by molten recombination of myristic acid, tetradecanol, and capric acid (MA-TD-CA) as phase change material and hydrophilic fumed silica (SiO 2 ) as porous carrier, and MIL-100(Fe) was synthesized by low-temperature solution method. Thermal analysis indicated that, under the optimized mass ratio of 28.8%MA-61.2%TD-10%CA, the CPCM containing 30 % SiO 2 could effectively prevent the leakage of ternary eutectic , with a suitable phase change temperature and enthalpy (21.74 °C, 96.70 J·g −1 ). The thermal and wet performance evaluation confirmed that the PCHCMs containing 40–50 % CPCM had human body comfortable phase change temperature (26.96–27.26 °C) and high saturation adsorption capacity (0.179–0.205 g/g) at 60 % RH as well as outstanding thermal and wet cycle reliability, indicating the novel MA-TD-CA/SiO 2 /MIL-100(Fe) PCHCM has broad application potential in room temperature and humidity control and building energy conservation .
研究领域:
建筑材料
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能源与环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2016
·Vol. 52
·期 5
·2673-2683
·
IF 2.302
Huang Zhangyu,Yi Mengji,Gao Huiping,Zhang Zhenlong,Mao Yanli
A strategy is demonstrated for simultaneous size and color tuning of KZnF 3 :Yb 3+ /Er 3+ nanocrystals through transition metal Mn 2+ doping. The experimental results indicate that the introduction of Mn 2+ into the KZnF 3 :Yb 3+ /Er 3+ reaction system facilitates the decrease of the crystal size. Moreover, in the case of a high concentration of Mn 2+ doping, the downshifting (DS) and upconversion (UC) luminescence all show a single red band emission. In this work, we mainly investigate the DS and UC energy transfer process among Mn 2+ /Yb 3+ /Er 3+ in KZnF 3 nanocrystals by the detection and analysis of the absorption, excitation, emission, and transient fluorescence spectra. The results show that both Mn 2+ and Yb 3+ ions can decrease the green emission while improving the red luminescence of Er 3+ . This DS and UC single red color tuning is significant for the application of nanoparticles in light conversion, biological labeling, or plant photosynthesis.
研究领域:
材料科学
·
光学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
CRYSTENGCOMM
·
2025
·
IF 2.6
Qiuyu Fang,Jialiang Luo,Chenghong Zhang,Wei Wang,Wei Ding,Ganhong Zheng,Zhigao Sheng
The phase selectivity and morphology of materials is an effective strategy to improve the electromagnetic wave absorption (EMWA). However, the preparation of EMWA materials with both controllable phase component and adjustable morphology remains a great challenge. Herein, a strategy of phase regulation through high magnetic field is proposed to achieve controllable adjustment of the phase and morphology of iron sulfide, thus promoting interface polarization to improve the EMWA performance. When a high magnetic field is introduced into the reaction, the single Fe3S4 phase is gradually evolved into FeS2 due to the action of magnetizing energy, which presents in the form of Fe3S4/FeS2 composite. And with the increase of magnetic field intensity, FeS2 content increases gradually. In addition, the magnetic field also induces the assembly of Fe3S4/FeS2 and tends to be staggered. Due to the regulation of phase and morphology, accompanied by the redistribution of conductive loss and interfacial polarization, so that the EMWA property of iron sulfide is effectively regulated. 9 T sample with a good impedance matching exhibits a minimum reflection loss value of −50.31 dB, and the effective absorption bandwidth (EAB) is extended to 4.5 GHz. This work has important guidance and inspiration for the design of phase and morphology controlled by the high magnetic field, and it has great application potential in regulating EMWA performance.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale
·
2019
·Vol. 11
·期 32
·15023-15028
·
IF 6.97
Chun Wu,Xiaoyang Wang,Wenli Pei,Dong Zhao,Kai Wang,Guojian Li,Qiang Wang
A 6 Tesla high magnetic field (HMF) was separately introduced into the nucleation stage and growth stage and into both stages during the wet-chemical synthesis of FePt nanoparticles. The HMF refined particle sizes and increased the nucleation rate in the nucleation stage and tailored shapes and refined sizes in the growth stage. Extension of nucleation time increased the nucleation rate more than that of the HMF, which increasing was higher enough to tailor the shapes of FePt nanoparticles. Controlling nucleation is a feasible strategy to tailor the shapes and sizes of wet-chemical synthesized nanoparticles.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2024
·
IF 4.7
Tao Peng,Chuanqiang Li,Liyun Song,Cui Liu,Feng Wang,Qianqian Chai,Shimin Li,Qiang Guo,Xuxu Zheng
Three Mn 2 O 3 with different morphologies and particle sizes were synthesized using MnBDC as precursor. Interestingly, the morphology and size of MnBDC can be easily regulated by changing the reaction solvents slightly. The Mn 2 O 3 -L catalyst with large layers and small crystal size exhibited the best catalytic activity for complete oxidation of propane, with T 50 of 266℃ and T90 of 311℃ at the WHSV of 120 L g −1 h −1 . The multi-layered structure and small crystal size of Mn 2 O 3 -L allowed it to possess a high surface area and more interfacial oxygen defects that facilitated oxygen mobility, improving the catalytic activity. It seems that the large precursor size of MnBDC-L slowed down the decomposition rate of ligands, promoting the formation of large layered structure and small crystal size of Mn 2 O 3 -L. This study offers a simple strategy to control the structure and crystal size of Mn 2 O 3 catalysts.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CRYSTENGCOMM
·
2016
·Vol. 18
·期 31
·5940-5951
·
IF 3.849
Jingjing Cao,Li Yuan,Shanshan Hu,Jianfeng Tang,Xianju Zhou,Jun Yang
Monodisperse ScF3 and NaScF4 nano-/micro-crystals were prepared by a simple solvothermal method. There were many important factors including the molar ratio of Na/F/(Sc + Ln) and Ln3+ doping to control the synthesis of the products. A phase transformation from monoclinic ScF3 to hexagonal NaScF4 was observed with different molar ratios of Na/F/Sc. Herein, the products doped with 1% Ln3+ (La–Lu, except Pm) demonstrated abundant phases, morphologies and sizes. Moreover, the products with different Lu3+ doping concentrations from 1% to 60% were prepared. The results revealed that different kinds of 1% Ln3+ (La–Lu, except Pm) and diverse concentrations of Lu3+ can modify the phase, morphology and size of the prepared products. A possible formation mechanism for the products with diverse morphologies is proposed. In addition, Ln3+-doped ScF3 or NaScF4 nano-/micro-crystals presented characteristic up/down-conversion fluorescence spectra.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
Small
·
2017
·Vol. 13
·期 30
·1700999
·
IF 8.643
Yanyan Xie,Yuefei Wang,Wei Qi,Renliang Huang,Rongxin Su,Zhimin He
Self-assembly of chiral nanostructures is of considerable interest, since the ability to control the chirality of these structures has direct ramifications in biology and materials science. A new approach to design chiral nanostructures from self-assembly of N -(9-fluorenylmethoxycarbonyl)-protected phenylalanine-tryptophan-lysine tripeptides is reported. The terminal charges can induce helical twisting of the assembled β-sheets, enabling the formation of well-defined chiral nanostructures. The degree and direction of twisting in the β-sheets can be precisely tailored through in situ pH and temperature modulations. This enables the assembly of reconfigurable chiral nanomaterials with easily adjustable size and handedness. These results offer new insight into the mechanism of helical twist formation, which may enable the precise assembly of highly dynamical materials with potential applications in biomedicine, chiroptics, and chiral sensing.
研究领域:
生物化学
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材料科学
·
纳米技术
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产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 35
·27901-27911
·
IF 3.84
Chunling Xin,Haijuan Zhan,Xin Huang,Hongguang Li,Ning Zhao,Fukui Xiao,Wei Wei,Yuhan Sun
Two type of modulators, including sodium acetate and triethylamine were used to synthesize nanosized HKUST-1 crystals with tailored size and morphology using a coordination modulation method. The results of X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and N2 sorption isotherms confirm that the size of the HKUST-1 crystals can be tuned from the micron scale to the nanoscale through precise modulation of the amounts of the modulators. Moreover, hierarchical porous structures are obtained with the addition of modulators. It is suggested that a moderate acid–base environment and capping groups play an important role in controlling the size and morphology of HKUST-1. Dynamic CO2 breakthrough experiments illustrate that the CO2 capacity of nanosized HKUST-1 crystals is superior to that of micron-sized HKUST-1 crystals under low CO2 partial pressure conditions (0.1 bar). Besides, the CO2 adsorption capacity of nanosized HKUST-1 crystals was maintained after ten adsorption/desorption cycles.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Jinyi Zhu,Yufei Cheng,Wenwan Zhang,Junfeng Zhao,Qian Sun,Xiaoyun Hu,Hui Miao
As an n-type narrow band gap ternary sulfide semiconductor, CdIn 2 S 4 exhibits favourable photoelectrochemical (PEC) water splitting performance. However, severe photogenerated carrier recombination and slow surface dynamics at the interface of monomer CdIn 2 S 4 restrict its application. Herein, we addressed the problem by fabricating a TiO 2 /CdIn 2 S 4 -annealed photoanode by two-step anodization method, hydrothermal method and annealing treatment. As a result, the TiO 2 /CdIn 2 S 4 -annealed photoanode exhibited 6.21 mA/cm 2 at 1.23 V vs . RHE, which was much higher than the pure CdIn 2 S 4 (0.05 mA/cm 2 ) and TiO 2 (0.14 mA/cm 2 ), and was 9 times higher than TiO 2 /CdIn 2 S 4 (0.68 mA/cm 2 ). This excellent performance can be attributed to the synergistic effect of interfacial charge regulation (introducing TiO 2 NTs as electron transport layer) and surface defect regulation (introducing sulfur vacancies as OER active centers to facilitate hole transport). By this way, the photogenerated electrons and holes of CdIn 2 S 4 were simultaneously extracted in opposite directions. Experimental characterizations confirmed the introduction of TiO 2 and sulfur vacancies can enhance the separation and injection efficiency of carriers. This work provides a new idea for regulating interface charges and surface defects to improve the PEC activity of CdIn 2 S 4 .
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2017
·
IF 4.798
Panpan Sun,Taian Huang,Ziyu Chen,Liangyu Tian,Huihui Huang,Niu Huang,Sha Zhou,Min Long,Yihua Sun,Xiaohua Sun
The design and facile fabrication of highly efficient, cost-effective and earth abundant counter electrode material on an electrode surface is highly desirable for the application of dye-sensitized solar cells (DSSCs). Herein, using a N,N-dimethylformamide based solution process, transition metal chalcogenide Ni x S y films have been obtained by spin-coating a NiCl 2 -thiourea (Ni-Tu) solution combining mild thermal treatment. XRD, SEM and TEM characterizations reveal that the current procedure allows for phase composition (Ni 3 S 2 , NiS and NiS-NiS 2 ), crystallinity , morphology (film uniformity and compactness) control of the films through simple adjusting Ni/S ratio in the precursor solution. Electrochemical analysis indicates that the FTO supported Ni 3 S 2 and NiS films exhibit excellent electrocatalytic activity toward the reduction of triiodide, resulting in higher photo-electric conversion efficiencies of 6.86% and 6.95% when used as counter electrode in DSSCs, versus 6.66% for Pt. In particular, even without the support of conductive FTO layer, Hall effect measurements and electrocatalytic analysis reveal that pristine Ni x S y films exhibit good electrical conductivity and electrocatalytic activity, yielding a highest photo-electric conversion efficiency of 4.41% when used as counter electrode in DSSCs. Our study thus provides a facile procedure which allows for composition, morphology optimization and high performance for low-cost, large-scale DSSC application.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）