BIOTECHNOLOGY AND APPLIED BIOCHEMISTRY
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2016
·Vol. 64
·期 2
·251-258
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IF 1.429
Hong-De Yan,Zhao Wang,Jun-Qing Qian
A mycelium-bound lipase from Aspergillus oryzae (AOL) exhibited excellent enantioselectivity for kinetic resolution of ( RS )-1-phenylethanol (( RS )-1-PE) in organic solvent. The various reaction parameters affecting the conversion and enantioselectivity were studied, including type of acyl donor, solvent, molar ratio, temperature, enzyme amount, and substrate concentration. The optimum reaction conditions were found to be transesterification with vinyl acetate at 30 °C in methyl tert -butyl ether with a vinyl acetate: ( RS )-1-PE molar ratio of 1:1 and an enzyme concentration of 60 g/L. At the optimum reaction conditions, the conversion could reach above 46% with >99% enantiomeric excess of the product, ( R )-1-phenylethyl acetate, when the substrate concentration was below 1.4 M. The enzyme displayed an excellent enantioselectivity with an E -value of >200 and a strong tolerance for high substrate concentration of up to 1.8 M. Those results indicated that AOL was a promising biocatalyst in the kinetic resolution of ( RS )-1-PE.
研究领域:
生物化学
·
酶工程
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PubMed
高影响因子
JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY
·
2018
·
IF 2.869
Xiaoyu Zhou,Xinwei Liu,Spencer Chiang,Wenbo Cao,Ming Li,Zheng Ouyang
Ion trap is an excellent platform to perform tandem mass spectrometry (MS/MS), but has an intrinsic drawback in resolving power. Using ion resonant ejection as an example, the resolution degradation can be largely attributed to the broadening of the resonant frequency band (RFB) between ion motion and driving alternative-current (AC). To solve this problem, stimulated motion suppression (STMS) was developed. The key idea of STMS is the use of two suppression alternative-current (SAC) signals, which both have reversed initial phases to the main AC. The SACs can block the unexpected sideband ion resonances (or ejections), therefore playing a key role in sharpening the RFB. The proof-of-concept has been demonstrated through ion trajectory simulations and validated experimentally. STMS provides a new and versatile means for the improvement of the ion trap resolution, which for a long time has reached the bottleneck through conventional methods, e.g., increasing the radio-frequency (RF) voltage and decreasing the mass scan rate. At the end, it is worth noting that the idea of STMS is very general and principally can be applied in any RF device for the purposes of high-resolution mass analysis and ion isolation.
研究领域:
分析化学
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质谱学
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PubMed
高影响因子
Journal of Environmental Sciences
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2020
·
IF 4.302
Zhao-Feng Yuan,Williamson Gustave,Raju Sekar,Jonathan Bridge,Jia-Yue Wang,Wei-Jia Feng,Bin Guo,Zheng Chen
The redox-sensitive elements, such as iron, manganese, sulfur, phosphorus, and arsenic, shift their speciation every millimeter (mm) across the soil-water interface in the flooded soil environments. Monitoring of element speciation at this high-resolution (HR) within the SWI is still difficult. The key challenge lies in obtaining sufficient porewater samples at specific locations along the soil gradient for downstream analysis. Here with an optimized inductively coupled plasma mass spectrometry (ICP-MS) method and a HR porewater sampler, we demonstrate mm-scale element profiles mapping across the SWI in paddy soils. High-concentrations of iron and manganese (> 10 mg/L) were measured by ICP-MS in an extended dynamic range mode to avoid signal overflow. The iron profile along the SWI generated by the ICP-MS method showed no significant difference ( p < 0.05) compared to that measured independently using a colorimetric method. Furthermore, four arsenic (arsenite, arsenate, monomethylarsonic and dimethylarsinic acid), two phosphorus (phosphite and phosphate) and two sulfur (sulfide and sulfate) species were separated in 10 min by ion chromatography -ICP-MS with the NH 4 HCO 3 mobile phase. We verified the technique using paddy soils collected from the field, and present the mm-scale profiles of iron, manganese, and arsenic, phosphorus, sulfur species (relative standard deviation < 8%). The technique developed in this study will significantly promote the measurement throughput in limited samples (e.g. 100 μL) collected by HR samplers, which would greatly facilitate redox-sensitive elements biogeochemical cycling in saturated soils.
研究领域:
土壤学
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环境科学
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分析化学
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DOI
PubMed
高影响因子
Nature Communications
·
2023
·Vol. 14
·期 1
·1-8
·
IF 16.6
Song Zihao,Du Xinyuan,He Xin,Wang Hanqi,Liu Zhiqiang,Wu Haodi,Luo Hongde,Jin Libo,Xu Ling,Zheng Zhiping,Niu Guangda,Tang Jiang
Solution-processed polycrystalline perovskite film is promising for the next generation X-ray imaging. However, the spatial resolution of current perovskite X-ray panel detectors is far lower than the theoretical limit. Herein we find that the pixel level non-uniformity, also known as fixed pattern noise, is the chief culprit affecting the signal-to-noise ratio and reducing the resolution of perovskite detectors. We report a synergistic strategy of rheological engineering the perovskite suspensions to achieve X-ray flat panel detectors with pixel-level high uniformity and near-to-limit spatial resolution. Our approach includes the addition of methylammonium iodide and polyacrylonitrile to the perovskite suspension, to synergistically enhance the flowability and particle stability of the oversaturated solution. The obtained suspension perfectly suits for the blade-coating process, avoiding the uneven distribution of solutes and particles within perovskite films. The assembled perovskite panel detector exhibits greatly improved fixed pattern noise value (1.39%), high sensitivity (2.24 × 10 4 μC Gy air −1 cm −2 ), low detection limit (28.57 nGy air ·s −1 ) as well as good working stability, close to the performance of single crystal detectors. Moreover, the detector achieves a near-to-limit resolution of 0.51 lp/pix.
研究领域:
材料科学
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放射学
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工程学
·
物理学
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PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Yixin Kuang,Suxin Zhou,Cheng Mao,Xiaoying Feng,Juan Zheng,Gangfeng Ouyang
High-resolution separation of numerous isomers is highly desirable for their high-quality analysis, yet challenging, which puts forward high requirements on the precise design of stationary phase. Herein, flexible 4- tert -butylcalix[n]arenes (TBCx[n]s) with different cavities have been intelligently integrated with in-situ grown UiO-66 coatings, to investigate their separation efficiencies for alkane and substituted benzene isomers. The modifications of UiO-66 with TBCx[n]s have made up for the deficiency of UiO-66 on the separation of ethylbenzene and styrene. The effects of TBCx[n]s on the separation performance of UiO-66@TBCx[n]s have demonstrated distinct regularities, i.e., the effects of TBCx[6] are superior to those of TBCx[8], while the TBCx[4] is the least effective. The baseline separation of all analytes has been achieved by the UiO-66@TBCx[6] column with enhanced selectivity and improved separation resolution (Rs). For the six groups of isomers that are most difficult to separate, the corresponding selectivity and Rs are greater than 1.09 and 5.48, respectively, confirming the outstanding separation performance of the UiO-66@TBCx[6] column and the feasibility of integrating soft supramolecule and rigid MOF.
研究领域:
化学工程
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材料科学
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分析化学
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DOI
高影响因子
ACS Applied Polymer Materials
·
2024
·
IF 4.4
Zhongwang Li,Wurikaixi Aiyiti,Cijun Shuai,Lanlan Dong
Three-dimensional bioprinting has emerged as a promising technique for creating personalized scaffolds. However, traditional extrusion-based methods face challenges with resolution and structural fidelity. This study aims to introduce a hybrid bioink, combining N-acryloylglycinamide (NAGA) with a rheology modifier to enhance both the stability and precision of printed designs. Additionally, we implemented a controlled immersion shrinkage process to further enhance the resolution. Immersing the printed structures in a 55% w/v tannic acid (TA) solution, the average grid area was reduced to 35.21% of its original size, significantly improving resolution. This treatment also boosted the antioxidant properties of the hydrogel, achieving a 90.5% ABTS removal rate. The hydrogel demonstrated excellent cytocompatibility, enhanced cell proliferation, and maintained high-resolution printability and antioxidant properties, making it a promising biomaterial for soft tissue regeneration.
研究领域:
生物材料学
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组织工程学
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DOI
高影响因子
ACS Applied Nano Materials
·
2025
·
IF 5.5
Dacheng Xia,Jianping Li,Qiuyi Zhang,Shuwen Shen,Chenxu Sheng,Chunxiao Cong,Zhi-Jun Qiu,Laigui Hu,Ran Liu
With tunable and exceptional optical properties, quantum dots (QDs) have shown promise as valuable luminescent materials for various visual applications. However, achieving the economical and facile manufacturing of QD patterns still remains a challenge for high-resolution applications. QD arrays with pixel sizes down to micrometers are difficult to achieve with conventional techniques. In this work, a low-cost dewetting-assisted self-assembly approach for patterning QDs was demonstrated using oleophilic/oleophobic patterns on different substrates treated by lithography and surface modification. High-resolution ordered droplet arrays of UV-curable QD ink were formed on prepatterned templates. Resultant large-area QD arrays with a pixel size down to 5 μm exhibited a high resolution of 2540 pixels per inch (PPI). Furthermore, dual-color microarrays with a resolution exceeding 4 kPPI were achieved by transfer-printing red and green QD microdot patterns onto a receiving substrate. High-resolution fluorescent anticounterfeiting labels were then successfully demonstrated, implying an avenue for low-cost high-resolution QD patterns for luminescent applications, such as optical anticounterfeiting, information encryption, and displays.
研究领域:
材料科学
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光学工程
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DOI
高影响因子
BIOMATERIALS
·
2025
·
IF 12.9
Bingjie Li,Jinbin Pan,Ruijie Zhang,Bing Han,Yujie Zhao,Guijun Liu,Yujie Tong,Yujing He,Guangchao Xie,Ruxia Liu,Ting Zhou,Quan Zhang,Shao-Kai Sun
High-resolution vascular imaging at tens of micrometers in deep tissues in vivo remains a critical challenge. Ultrahigh field susceptibility-weighted imaging (SWI) holds promise but lacking compatible high-sensitivity imaging probes. Herein, we show a holmium (Ho)-based nanoprobes-enhanced SWI strategy for ultrahigh-resolution imaging of cerebral microvessels at 9.4 T. The polyethylene glycol (PEG)-NaHoF 4 nanoprobes (NPs) fabricated via coprecipitation synthesis combined with PEG modification possess uniform size, appropriate hydrodynamic size (20 nm), good biocompatibility, and long circulation half-life (710 min). Notably, the PEG-NaHoF 4 NPs exhibit high r 2 / r 1 742.7) and T 2 * relaxivity ( r 2 *, 73.16 s -1 mM -1 ) under 9.4 T due to the large magnetic moment (∼10.6 μ B ) and short electronic relaxation time (∼10 -13 s) of Ho 3+ . The high susceptibility of PEG-NaHoF 4 NPs in blood vessels induces a significant blooming effect, resulting in a magnified vascular appearance on SWI. In vivo high-resolution imaging of cerebral microvessels with diameters as small as 10 μm is achieved using PEG-NaHoF 4 NPs-enhanced SWI under 9.4 T. In two representative brain disease models, glioma and stroke, this nanoprobe enables high-resolution visualization of tumor vasculature and post-stroke collateral circulation, respectively. Our study offers a new paradigm for precise diagnosis of vascular-related diseases, providing a robust tool for their diagnosis, treatment, and prognosis assessment.
研究领域:
医学影像学
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神经科学
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材料科学
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DOI
PubMed
高影响因子
Nature Communications
·
2025
·Vol. 16
·期 1
·1-12
·
IF 15.7
Zhou Zi’an,Zheng Jinxiao,Ruan Shihao,Yue Guichu,Feng Tiao,An Yini,Wu Meimei,Wang Nü,Zhou Shuyun,He Linfeng,Sun Chenghua
Fast neutron radiography offers exceptional penetration for high-density and bulky objects, yet its resolution is hindered by light scattering in conventional scintillators and screen fabrication techniques. To address this, here, we develop a transparent glassy Mn-based hybrid metal halide scintillation screen, (BTPP) 1.8 (HTPP) 0.2 MnBr 4 (BTPP + = butyltriphenylphosphonium, HTPP + = heptyltriphenylphosphonium), leveraging temperature-dependent ordered-disordered transitions. The large-area screen boasts >70% visible light transmittance (500–800 nm), a high photoluminescence quantum yield (~85.54%), and threefold higher light output than commercial ZnS (Ag): PP screens. With a spatial resolution of 5 lp mm −1 , it surpasses existing scintillators. This hybrid material enables imaging of heavy objects with clear hierarchical details, providing accurate data for non-destructive detection while offering an alternative approach to scintillator design, advancing the potential of fast neutron radiography.
研究领域:
核成像
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材料科学
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辐射探测
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光学材料
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无损检测
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产品关联
DOI
PubMed
高影响因子
ADVANCED MATERIALS
·
2025
·
IF 26.8
Jinmei Song,Yuhong He,Haijing Hu,Mingbian Li,Chenglong Li,Bai Yang,Haotong Wei
Computed tomography (CT) imaging has emerge as an effective medical diagnostic technique due to its rapid and 3D imaging capabilities, often employing indirect imaging methods through scintillator materials. Arraying scintillators that can confine light scattering to enable high-resolution CT imaging remains an area of ongoing exploration for emerging perovskite scintillators. Here an anti-scattering cesium lead bromide (CsPbBr 3 ) scintillator array embedded within a polyurethane acrylate matrix for CT imaging using a cost-effective solution-processed method is reported. Due to the large refractive index contrast between the scintillator and matrix, photon propagation can be well confined within the CsPbBr 3 scintillator array to significantly suppress the light scattering and enhance the light collection efficiency by nearly two times compared to the monolithic film. Furthermore, the scintillator array exhibits low-dosage and high-resolution CT imaging capability by reconstructing a 3D tooth image with a good spatial resolution of 20.1 lp cm −1 at a low effective dose of 0.22 mSv. This work highlights that the CsPbBr 3 scintillator array is a highly promising candidate for CT imaging.
研究领域:
医学影像
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材料科学
·
放射学
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DOI
PubMed
高影响因子
TALANTA
·
2024
·
IF 5.6
Al-Fakih Ali Mohammed,Chaohong Feng,Ting Jiang,Wei Xu
Miniaturized mass spectrometers, with their increasing portability and performance enhancements, play a crucial role in selectively analyzing target compounds within complex mixtures, particularly in situ environments. As part of our ongoing efforts to enhance the analytical capabilities of the custom-built "brick" mass spectrometer, this study compared and optimized methods for ion isolation using Stored Waveform Inverse Fourier Transform (SWIFT) and Grid-SWIFT waveforms. The efficacy of the SWIFT and Grid-SWIFT waveforms in selective ion isolation was investigated, and through optimization of both waveforms, improved ion isolation efficiency, and peak resolution were demonstrated by adjusting waveform duration and amplitude. The results conclusively showed that Grid-SWIFT outperforms traditional SWIFT waveforms in enhancing the isolation of target ions. Additionally, a novel simulation-based approach was developed to simulate the behavior of ion trajectories under the SWIFT and Grid-SWIFT waveforms within LIT to provide a theoretical basis for better performance of the Grid-SWIFT waveforms. Results show that longer waveform durations help reduce energy leakage, providing higher isolation efficiency. Grid-SWIFT waveforms exhibited significantly less energy leakage compared to SWIFT waveforms. Consequently, using Grid-SWIFT as isolation waveforms improved the mass spectra' intensity and resolution.
研究领域:
分析化学
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质谱技术
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仪器科学与技术
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PubMed
高影响因子
IEEE SENSORS JOURNAL
·
2024
·Vol. 24
·期 11
·17560-17569
·
IF 4.3
Weicen Chen,Boquan Wang,Jianzhong Chen,Chenzhi You,Jing Yao,Dawei Wu
Intraluminal ultrasonic (ILUS) technology, an advanced interventional imaging technique, employs a miniaturized high-frequency ultrasound transducer mounted at the tip of a thin catheter to visualize anatomical structures within the human body. This allows for the acquisition of high-quality images of lesions in close proximity. However, existing ILUS probes predominantly offer specialized visualization in a single direction of the ultrasound catheter due to space constraints within the catheter, posing challenges to the fabrication process. In this study, an ILUS high-frequency mini-convex array probe was developed which featured 64 array elements arranged in a curvilinear configuration, providing a 90° imaging field of view. The mini-convex array was housed within a stainless-steel tube with an outer diameter of 4 mm, positioned such that its central imaging axis was oriented at a 45° angle relative to the axial direction of the tube. This configuration enabled observation of objects ahead of the catheter, even though not entirely covered, and offered detailed features of the interior configuration on its side. This probe exhibited an average center frequency, −6 dB bandwidth, and sensitivity of approximately 17.85 MHz, 61.95%, and 32.64 mV, respectively. Imaging of a wire phantom yielded axial and lateral resolutions at 5 mm depth of approximately 0.11 and 0.25 mm, respectively. Subsequently, the actual imaging capability was assessed through ex vivo imaging of the artery and esophagus of a swine, demonstrating the suitability of the high-frequency mini-convex array probe for ILUS imaging applications.
研究领域:
医学影像
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超声技术
·
生物医学工程
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DOI
高影响因子
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