BIOLOGY AND FERTILITY OF SOILS
·
2024
·
IF 5.1
Wang Jipeng,Li Min,Wang Qitong,Zhang Ziliang,Wang Dungang,Zhang Peipei,Li Na,Zhong Yiqiu,Yin Huajun
It remains unclear whether microbial carbon limitation exists in the rhizosphere, a microbial hotspot characterized by intensive labile carbon input. Here, we collected rhizosphere soils attached to absorptive and transport roots and bulk soils in three alpine coniferous forests and evaluated the limiting resources of microbes based on the responses of microbial growth ( 18 O incorporation into DNA) and respiration to full-factorial amendments of carbon, nitrogen, and phosphorus. The results showed that adding carbon enhanced microbial growth and respiration rates in the rhizosphere soils by 1.2- and 10.3-fold, respectively, indicating the existence of carbon limitation for both anabolic and catabolic processes. In contrast, the promoting effects of nutrient addition were weak or manifested only after the alleviation of carbon limitation, suggesting that nutrients were co-limiting or secondarily limiting resources. Moreover, the category and extent of microbial resource limitations were comparable between the rhizosphere of absorptive and transport roots, and between the rhizosphere and bulk soils. Overall, our findings offer direct evidence for the presence of microbial carbon limitation in the rhizosphere.
研究领域:
生态学
·
微生物学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Physical Chemistry Letters
·
2024
·
IF 4.8
Zibo Cheng,Yeqin Guan,Hong Wen,Zhao Li,Kaixun Cui,Qijun Pei,Shangshang Wang,Claudio Pistidda,Jianping Guo,Hujun Cao,Ping Chen
Lithium hydride (LiH), a saline hydride with a hydrogen density of 12.6 wt %, is highly thermostable, which hinders its extensive application in hydrogen storage. In this study, we demonstrate a distinct photodecomposition of LiH under ambient conditions. Ultraviolet–visible (UV–vis) illumination induces hydrogen release and creates surface hydrogen vacancies on LiH. The subsequent H– migration enables hydrogen desorption and the accumulation of vacancies at the subsurface, resulting in the generation of metallic Li clusters. Rehydrogenation, on the contrary, can be charged under UV–vis illumination in 1 bar H2. Such phenomena show that the thermodynamic and kinetic limits in the re/dehydrogenation of LiH can be broken under illumination, which allows hydrogen storage over the LiH surface at temperatures ∼600 K lower than those of the corresponding thermal process. This work provides new insights into the interaction of semiconducting hydrides and photons and opens an avenue for the development and optimization of materials for hydrogen storage and related photodriven reactions.
研究领域:
储氢
·
材料科学
·
表面化学
·
光化学
·
半导体氢化物
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2023
·
IF 13.6
Xin Zhang,Qingling Fu,Hongqing Hu,Jun Zhu,Yonghong Liu
The co-oxidation of Fe(II) and As(III) occurs under aerobic conditions , and Fe(II) may largely determine the fate of As(III), but the effect of Fe(II) on the As(III) oxidation is barely explored. In this research, the limiting and driving roles of Fe(II) in As(III) oxidation were systematically studied through batch kinetic studies in combination with X-ray photoelectron spectroscopy (XPS) depth profiling, scanning electron microscopy and energy dispersive X-ray spectrometry (SEM-EDS), and quenching experiments. The results showed that As(III) oxidation efficiency increased with the increase of Fe/As molar ratio (from 63.1% to 98.3%), but decreased with the increase of pH (from 96.0% to 44.2%) and the increase of air flow rate (from 88.1% to 75.1%). The Fe(II) oxidation rate increased with the increase of pH and air flow rate. When Fe(II) was oxidized rapidly, As(III) was more likely to be immobilized in the “inner sphere” of formed Fe (hydr)oxides, limiting As(III) oxidation. On the other hand, Fe(II) was oxidized to produce Fe (hydr)oxides to adsorb or fix As(III); meanwhile, the ROS generated by Fenton-like reaction of Fe(II) promoted As(III) oxidation, especially, •O 2 − and H 2 O 2 were important ROS that drove the As(III) oxidation. These findings might provide a new insight for Fe(II) and As(III) geochemistry cycling in naturally occurring environment.
研究领域:
环境科学
·
地球化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL & PHARMACEUTICAL BULLETIN
·
2011
·Vol. 59
·期 8
·1045-1047
·
IF 1.507
Yibing Guo,Xiaohong Li,Yahong Zhao,Yongxing Si,Hui Zhu,Yumin Yang
Salidroside is a phenylpropanoid glycoside isolated from Rhodiola rosea L., a traditional Chinese medicinal plant, and has displayed a broad spectrum of pharmacological properties. In this paper, two analogues were prepared with the glucosamine and N-acetylglucosamine as glycosyl donor, 2-(4-hydroxyphenyl)ethanol as glycosyl acceptor. The effects of them over PC12 cell model exposed to hypoglycemia and serum limitation were assessed with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, Flow Cytometry and Western blot analysis.
研究领域:
药理学
·
神经生物学
✓ 已验证
DOI
PubMed
高影响因子
Advanced Intelligent Systems
·
2019
·Vol. 1
·期 7
·1900064
·
IF 0
Daolin Wang,Zhihua Lin,Chang Zhou,Changyong Gao,Qiang He
One of the great challenges in the field of tiny machines is the capability of engineering liquid metal micromachines to autonomously move within confining channels to perform various complex tasks. Herein, liquid metal gallium micromachines that significantly increase their velocity in confining channels with adaptive deformation under exposure to an electric field are presented. The liquid metal gallium micromachines move toward the negative electrode under the propulsion of hydrogen bubbles, which is obviously different from the previous report that liquid metal gallium alloy (i.e., Galinstan) micromachines move to the positive electrode, owing to the surface tension gradient. More importantly, the liquid metal gallium micromachine can adaptively deform and accelerate in confined channels. The velocity of liquid metal gallium micromachines increases with the decrease in the width of channels. It is found that the speed-up motion of liquid metal gallium micromachines is caused by the enhanced electro-osmosis effect in confining channels. The findings not only help understand the role of the confinement effect on the motion of liquid metal micromachines but also provide a novel strategy to manipulate the motion velocity of liquid metal micromachines for specific applications.
研究领域:
材料科学
·
微纳米技术
·
物理学
✓ 已验证
产品关联
DOI
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2023
·
IF 11.4
Fengyuan Chen,Jie Ma,Zihan Zhong,Hongbin Liu,Aijun Miao,Xiaoshan Zhu,Ke Pan
Marine diatoms are currently facing increasing threats from microplastic (MP) pollution that is intertwined with the disturbed nutrient stoichiometry in seawater. The effects of nutrient imbalances such as silicon (Si) limitation on the interactions between diatoms and MPs remain poorly understood. In contrast to previous studies which mainly focused on MP toxicity, this study emphasizes how Si availability affects nano-scale interactions between pristine polystyrene MPs and diatom surfaces. Results showed that Si-starved cells were less tolerant to MP toxicity than the Si-enriched counterparts. Si limitation significantly changed the configuration and chemical composition of the perforated frustules, forming less negatively charged, more adhesive, and mechanically weaker cells. All of these changes facilitated the adsorption and hetero-aggregation between the diatom cells and MPs and compromised the diatoms’ resistance to MP attack. Our study provides novel insights into the effects of pristine MPs in the marine environment under the context of dynamic nutrient conditions.
研究领域:
海洋生物学
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
CRYSTENGCOMM
·
2016
·Vol. 19
·期 1
·72-79
·
IF 3.849
Tao Yang,Jianmei Liu,Jinhui Dai,Yongsheng Han
Here, we report a general role of chemical diffusion and reaction in shaping particles. It is supposed that chemical diffusion and reaction play a role in shaping particles by changing the chemical distribution around the growth front of particles. Based on this understanding, three growth modes of particles are proposed in this paper, namely, reaction-limited mode, diffusion-limited mode, and reaction–diffusion balance mode. Silver particles are synthesized in different growth modes by various methods. No matter which method is employed, silver particles synthesized in the same mode have similar morphologies. To further generalize diffusion and reaction effects, copper and gold particles are synthesized. The morphological evolution of these two types of particles is similar to that of silver. These results indicate the general role of chemical diffusion and reaction in shaping particles, promising that a regulation on these two kinetic factors is a green and powerful technique for rational synthesis of materials.
研究领域:
材料科学
·
化学
·
纳米技术
✓ 已验证
DOI
高影响因子
JOURNAL OF PHYSICAL CHEMISTRY B
·
2016
·
IF 3.187
Yihuang Chen,Tiansheng Gan,Chunfeng Ma,Linge Wang,Guangzhao Zhang
Crystallization of polymer chains confined on a surface greatly influences surface properties. We have grafted comb-like copolymer, consisting of poly(2-hydroxyethyl methacrylate) (PHEMA) backbone and semicrystalline poly(ε-caprolactone) (PCL) side chains, on silicon surface and investigated the crystallization of such confined PCL chains upon solvent evaporation by using atomic force microscopy (AFM), grazing incidence wide-angle X-ray scattering (GI-WAXS), and polarized optical microscope (POM). Our studies reveal that the PCL chains align and form “flat-on” lamellae at a low PCL chain density. As the chain density increases, the comb-like polymer (PHEMA-g-PCL) chains undergo pancake-to-mushroom-to-brush transition, and the lamellae turn from “flat-on” to “edge-on” in orientation. Further increasing PCL chain density leads the “edge-on” lamellae to change from a quasi-two-dimensional (quasi-2D) to quasi-three-dimensional (quasi-3D). Because of the confinements of polymer chains, we can observe the evolution of spherulites at different stages during the mushroom-to-brush transition of PHEMA-g-PCL chains. The confinements also result in knobbly substructures in the edge-on lamellae.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
JOURNAL OF BIOTECHNOLOGY
·
2020
·
IF 3.503
Hengqian Lu,Haiqin Chen,Xin Tang,Qin Yang,Hao Zhang,Yong Q. Chen,Wei Chen
Lipid hyperaccumulation in oleaginous microorganisms is generally induced by nitrogen limitation, while oxygen supply can influence biomass growth and cell metabolism. Although strategies based on nitrogen limitation or oxygen control have been extensively explored and applied in various oleaginous microorganisms, the role of oxygen supply in nitrogen limitation induced lipid hyperaccumulation still remains unclear. Here, we systematically surveyed the effects of oxygen supply on the oleaginous fungus M. alpina cultured in nitrogen limited conditions through integration of physiochemical parameters and metabolomics analysis. Our results indicated that a high oxygen supply promoted carbon/nitrogen consumption and was used for rapid biomass synthesis, while either high or low oxygen supply conditions were adverse to lipid and ARA accumulation. Different oxygen supply level significantly affected the balance between fermentation for lipid synthesis and respiration for energy generation. Under nitrogen limitation, a suitable oxygen supply promoted the recycling of preformed nitrogen and increased the redirection of carbon towards fatty acid synthesis through the hub centred around glutamic acid coupled to the intermediate metabolism of carbon in the TCA cycle, while a high oxygen supply favored the respiration process and enhanced the degradation of LC-PUFAs, rather than fermentation for fatty acid synthesis. This system-level insight reveals the underlying metabolic mechanism of oxygen control in nitrogen limitation induced lipid accumulation, and provides theoretical support for the integration of oxygen control with nutrient supply for efficient microbial oil production.
研究领域:
微生物学
·
代谢生物学
✓ 已验证
DOI
PubMed
高影响因子
Sustainable Energy & Fuels
·
2020
·Vol. 4
·期 6
·2869-2874
·
IF 5.503
Jingyang Tian,Jiaxin Li,Anlin Feng,Xinran Han,Yuancai Lv,Mingyang Ma,Chong Lin
Current research on MoS2/graphene hybrids for the hydrogen evolution reaction (HER) reveals that there is still a huge challenge due to restacking and the scarcity of active sites. In this work, ultramicro MoS2 nanosheets with good dispersion and rich active sites are vertically grown on graphene via a self-limited growth strategy (S–MoS2). Moreover, carbon nanotube (CNT) scaffolds can effectively limit the restacking of graphene and MoS2, accelerating the transport of electrons and electrolytes. The synergism among the multi-function structures and composition control can improve the electrochemical HER activity. The obtained S–MoS2/rGO/CNTs exhibits a low overpotential of 159 mV (vs. RHE) at 10 mA cm−2 and a small Tafel slope of 85 mV dec−1 in 0.5 M H2SO4. Moreover, the S–MoS2/rGO/CNTs shows excellent electrochemical durability at 10 mA cm−2 for 18 h. This work supplies a fresh strategy to design high-performance and cost-effective MoS2-based catalysts for the HER.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2023
·Vol. 15
·期 21
·4235
·
IF 5
Mingyu Guo,Chengfeng Zhou,Yuandong Cui,Wei Jiang,Guangting Han,Zhan Jiang,Haoxi Ben,Xiaoli Yang
The catalytic conversion of cellulose to lactic acid (LA) has garnered significant attention in recent years due to the potential of cellulose as a renewable and sustainable biomass feedstock. Here, a series of Au/W-ZnO catalysts were synthesized and employed to transform cellulose into LA. Through the optimization of reaction parameters and catalyst compositions, we achieved complete cellulose conversion with a selectivity of 54.6% toward LA over Au/W-ZnO at 245 °C for 4 h. This catalyst system also proved effective at converting cotton and kenaf fibers. Structural and chemical characterizations revealed that the synergistic effect of W, ZnO, and Au facilitated mesoporous architecture generation and the establishment of an adequate acidic environment. The catalytic process proceeded through the hydrolysis of cellulose to glucose, isomerization to fructose, and its subsequent conversion to LA, with glucose isomerization identified as the rate-limiting step. These findings provide valuable insights for developing high-performance catalytic systems to convert cellulose.Keywords:cellulose conversion;lactic acid;reaction mechanism;rate-limiting step
研究领域:
生物化学
·
催化科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2018
·Vol. 6
·期 34
·16566-16573
·
IF 9.931
Danke Chen,Wensen Wang,Wen Ying,Yi Guo,Donghui Meng,Youguo Yan,Rongxin Yan,Xinsheng Peng
The modern global climate change and global warming of Earth make it an urgent need to develop emerging CO2 capture and storage techniques. Herein, we first reported the use of WS2 nanosheets to construct laminated membranes for CO2 separation. However, the WS2 membrane showed poor CO2 separation performance with Knudsen selectivities for N2/CO2 (1.28), CH4/CO2 (1.72) and H2/CO2 (4.96). To improve the performance, an ionic liquid (IL) 1-butyl-3-methyl imidazolium tetrafluoroborate ([BMIM][BF4]) with high CO2 solubility and practically no vapour pressure was used for filling the nanochannels of the WS2 membrane. Compared to the bulk IL, the nanoconfined IL exhibits higher freezing temperature, shift of vibration bands and higher interaction energy between CO2 and ILs. Besides, the prepared WS2 laminated membrane with the nanoconfined ionic liquid shows excellent selectivities for CO2/N2 (153.21), CO2/CH4 (68.81) and CO2/H2 (13.56) in single gas measurements as well as good CO2 permeance due to the nanoconfinement of the IL. The simulation results further confirmed and explained the CO2 separation mechanism. It indicates that the nanoconfinement of ILs into the nanochannels of two-dimensional materials is a novel way to achieve CO2-philic membranes to efficiently separate CO2 from other light gases.
研究领域:
材料科学
·
环境工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
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