ANALYTICAL CHEMISTRY
·
2024
·
IF 6.7
Weiwei Zhang,Miaoyu Chen,Qun Ma,Zhixiao Si,Sanmei Jin,Qiujiao Du,Limin Zhang,Yu Huang,Fan Xia
Artificial solid-state nanochannels featuring precise partitions present a highly promising platform for biomarker detection. While the significance of probes on the outer surface (POS) has been relatively overlooked in the past, our research highlights their crucial role in biosensing. Furthermore, the contribution of POS on the bullet-shaped asymmetric nanochannels has not been extensively explored until now. Here, we fabricated a series of bullet-shaped nanochannels, each featuring a distinct asymmetric structure characterized by different tip- and base-pore diameters. These nanochannels were further modified with explicit distributions at the inner wall (PIW), the outer surface (POS), and their combination (POS + PIW) for lysozyme sensing. The impact of diameters, structural asymmetry, and surface charge density on the sensing efficacy of POS and PIW was thoroughly examined through experimental investigations and numerical simulations. POS demonstrates great individual sensing performance for lysozyme within a broad concentration range, spanning from 10 nM to 1 mM. Furthermore, it improves the sensitivity when combined with PIW, particularly within the nanochannels featuring the smaller base-pore diameter, resulting in a 2-fold increase in sensing performance for POS + PIW compared to PIW at a concentration of 10 nM. These findings are substantiated by numerical simulations that closely align with the experimental parameters. The contributions of POS are notably amplified in the presence of smaller base pores and a higher degree of asymmetry within the bullet-shaped nanochannels. These findings elucidate the mechanism underlying the role of POS within bullet-shaped asymmetric nanochannels and open up new avenues for manipulating and enhancing the sensing efficiency.
研究领域:
生物传感
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纳米技术
·
蛋白质分析
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产品关联
DOI
PubMed
高影响因子
ADVANCED SYNTHESIS & CATALYSIS
·
2016
·Vol. 358
·期 13
·2116-2125
·
IF 6.453
Anguo Ying,Shuo Liu,Zhifeng Li,Gang Chen,Jianguo Yang,Hua Yan,Songlin Xu
A magnetic nanoparticles-supported chiral aminocyclohexane in combination with sulfamide, which was modified by an imidazolium ionic moiety, was prepared and characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), thermal gravimetric (TG) analysis and elementary analysis. The catalyst was successfully applied not only in the enantioselective Michael addition but also in the asymmetric aldol condensation to afford good to excellent yields (70–94%) and satisfactory stereoselectivity ( ee : 92–100%, dr : 91:9–99:1).The role of the ionic moiety was verified by comparison of the catalyst with an ionic moiety-free counterpart. The heterogeneous catalyst was easily separated and recovered using external magnetic force and can be used for up to five times without obvious loss in its catalytic activity.
研究领域:
有机化学
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催化化学
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材料科学
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DOI
高影响因子
Catalysts
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2022
·Vol. 12
·期 1
·83
·
IF 4.501
Cuiping Yu,Weilong Wu,Min Gao,Yu Liu
Asymmetric catalysis is the preferred method for the synthesis of pure chiral molecules in the fine chemical industry. Cellulose has long been sought as a support in enantioselective catalysis. Dialdehyde cellulose (DAC) is produced by the selective oxidation of cellulose and is used to bind 5,5′-diamino Binap by forming a Schiff base. Here, we report the synthesis of modified cellulose-supported Rh as a novel biomass-supported catalyst and the characterization of its morphology, composition, and thermal stability. DAC-BINAP-Rh was a very effective catalyst in the asymmetric hydrogenation of enamides and could be easily recycled. This work provides a novel supported catalyst that broadens the applications of cellulose in asymmetric catalysis.Keywords:asymmetric hydrogenation;cellulose;BINAP;heterogeneous catalysis
研究领域:
化学
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材料科学
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有机合成
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产品关联
DOI
高影响因子
SYNTHESIS-STUTTGART
·
2019
·Vol. 52
·期 02
·297-303
·
IF 2.867
Yi Zhang,Dongheng Zhou,Yongmin Ma,Jing Chen
A simple and efficient procedure for the synthesis of N-[(methylthio)methyl]benzamides and methylene-bridged unsymmetrical bisamides was achieved mediated by DMSO in the presence of acetic acid. DMSO plays a dual role in the transformation, as not only a solvent, but also an environmentally benign methylene source. The protocol provides new strategies for effective synthesis of unsymmetrical bisamides and avoids the use of transition-metal catalysts.
研究领域:
有机化学
·
绿色化学
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DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2025
·
IF 8.5
Zhe Dou,Pei-Ru Hu,Lin-Lin Song,Yi-Cheng Wang,Hao-Nan Tang,Zhen-Qi Weng,Ya-Jun Wang,Yuan-Qiang Cai
Carbonyl reductases (CRs) are promising biological macromolecules for the asymmetric synthesis of chiral secondary alcohols. A novel CR was evolved for efficient conversion of d -xylose into anti-aging ( S )-Pro-Xylane. Through extensive gene mining, an active carbonyl reductase Zm CR was identified from Zygofabospora marxiana with high reductive activity towards d -xylose-derived 1-C-(β- d -xylopyranosyl)-acetone (XPSA) and in situ cofactor regeneration capability. Using a three-round of concise engineering strategy, a hextuple mutant C85V/V128C/S129A/V161S/Y166H/T217A (M6) was identified from merely 157 mutants with specific activity of 46.00 U·mg −1 , about 306 folds of WT. The Shannon-Wiener index of M6 was 2.21, much higher than WT, indicating its extended substrate scope. M6 could efficiently catalyze the asymmetric reduction of 190 g·L −1 XPSA into ( S )-XPSP. The k cat / K M XPSA of M6 was 203.84 s −1 ·mM −1 , about 910 folds of WT. More non-bonded interactions were monitored in M6, contributing to the stabilization of reactive catalytic conformation. This study provides a promising biocatalyst for the chemoenzymatic synthesis of value-added anti-aging ( S )-Pro-Xylane from lignocellulosic d -xylose.
研究领域:
生物化学
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酶工程
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合成生物学
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DOI
PubMed
高影响因子
Bioresources and Bioprocessing
·
2018
·Vol. 5
·期 1
·1-12
·
IF 0
Zheng Liandan,Lin Jinping,Zhang Baoqi,Kuang Yuyao,Wei Dongzhi
A NAD(P)H-dependent enoate reductase (OYE2p) from Saccharomyces cerevisiae YJM1341 was discovered by genome data mining for asymmetric reduction of (E/Z)-citral to (R)-citronellal with high enantioselectivity.This enzyme was heterologously expressed in E. coli and characterized for its biocatalytic properties. OYE2p was identified with reduction activities toward a diverse range of ɑ,β-unsaturated compounds bearing conjugated aldehyde, ketone, imide, carboxylic acid and ester.OYE2p showed the highest specific activity at 40 °C and a pH optimum at 7.0–8.0. The stability of OYE2p was rather pH-independent, and the half-life time values of the enzyme at pH 6.0–8.0 were more than 257 h. With regard to the reduction of (E)-citral and (Z)-citral, OYE2p exhibited different selectivity patterns. (E)-citral was exclusively reduced to (R)-citronellal by OYE2p in ≥ 99% ee, which was independent on pH. OYE2p produced both enantiomers of citronellal from (Z)-citral, but showed (R)-citronellal formation tendency, and the ee value of (R)-citronellal was affected by pH in the reaction system. Accordingly, the ee values for (R)-citronellal formation increased with the increasing levels of E-isomer in the (E/Z)-citral mixture as well as the increase of pH. Under the reaction conditions (30 °C and pH 8.6), using purified OYE2p as catalyst, 200 mM (E/Z)-citral (an approximately 10:9 mixture of geometric E-isomer and Z-isomer) was efficiently converted to (R)-citronellal with 88.8% ee and 87.2% yield.All these positive features demonstrate high potential of OYE2p for practical synthesis of (R)-citronellal and in asymmetric reduction of activated alkenes.
研究领域:
生物化学
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酶工程
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合成生物学
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产品关联
DOI
BIORESOURCE TECHNOLOGY
·
2022
·
IF 11.889
Xiaoyu Chen,Zhe Dou,Tianwei Luo,Zewen Sun,Hongmin Ma,Guochao Xu,Ye Ni
Ancestral enzymes are promising for industrial biotechnology due to high stability and catalytic promiscuity. An effective protocol was developed for the directed resurrection of ancestral enzymes. Employing genome mining with diaryl alcohol dehydrogenase Kp ADH as the probe, descendant enzymes D10 and D11 were firstly identified. Then through ancestral sequence reconstruction, A64 was resurrected with a specific activity of 4.3 U·mg −1 . The optimum pH of A64 was 7.5, distinct from 5.5 of D10. The T15 50 and T m values of A64 were 57.5 °C and 61.7 °C, significantly higher than those of the descendant counterpart. Substrate spectrum of A64 was quantitively characterized with a Shannon-Wiener index of 2.38, more expanded than D10, especially, towards bulky ketones in Group A and B. A64 also exhibited higher enantioselectivity. This study provides an effective protocol for constructing of ancestral enzymes and an efficient ancestral enzyme of industrial relevance for asymmetric synthesis of chiral alcohols.
研究领域:
生物化学
·
工业生物技术
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DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2025
·
IF 8.2
Yue Liu,Wei Peng,Hancheng Ma,Jinsai Tian,Kao Wang,Zhaobo Zheng,Lin Xu,Yao Ding
Metal–organic frameworks have aroused growing interest in the research of energy conversion and storage. However, their specific configuration, especially the coordination environment of metal active sites, has not been well designed. Their role in regulating the structural reconstruction of pre-electrocatalysts remains ambiguous. Herein, this work reports a dual-ligand strategy to design a Ni-MOF with asymmetric Ni–O coordination, named Ni–BDC–DOBDC, which occupies unsaturated Ni sites and strengthens Ni–O bonds. As inspected by X-ray absorption near edge structure as well as a series of in situ and ex situ characterizations, this special Ni–O coordination contributes to Ov-NiOOH with rich oxygen vacancies during fast self-reconstruction at a lower potential. Moreover, theoretical results reveal that Ni sites in Ov-NiOOH occupy a higher d-band center, a lower adsorption energy barrier, and a more electronic negative surface in the oxygen evolution reaction, leading to good electrocatalytic performance. Overall, Ni–BDC–DOBDC catalysts exhibit a low overpotential of 202 mV at 10 mA cm–2 and outstanding stability within 240 h. The insights in this work pave the way for high-performance MOF-based catalysts by regulating their self-reconstruction kinetics through a new aspect of asymmetric ligand engineering.
研究领域:
材料科学
·
电化学
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产品关联
DOI
PubMed
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2024
·
IF 4.5
Yang Liu,Qi Lin,Xu Long,Shuting Zhang,Hong Dong,Yanjiang Song,Chuan Wu
Three kinds of α -triethylsiloxyl- ω -trimethoxysilyethyl-terminated oligomers (TES-PDMS-TMOS, TES-PTFPMS-TMOS, and TES-PDES-TMOS) were synthesized through an anion catalyzed non-equilibrium ring-opening polymerization reaction of cyclotrisiloxanes and subsequent hydrosilylation reaction with vinyltrimethoxysilane. As the in situ surface modification agent for mixed-size AlN inorganic fillers (1, 20 and 50 μm blended in a mass ratio of 3:5:9), these oligomers have been mixed with Vi-PDMS in a mass ratio of 1:2. Relative to that of silicone pastes using Vi-PDMS as the polymer matrix , the thermal conductivity of silicone pastes made from AlN particles treated with these oligomers is enhanced, while their thermal resistances decreased. With the change of the repeating unit structure in the oligomers, the silicone pastes prepared from these oligomer-treated AlN fillers differ significantly in filler content, thermal conductivity , and thermal resistance. When TES-PTFPMS-TMOS is used and filled with 800 parts (70.3 vol%) of hybrid AlN powders, a silicone paste with a thermal conductivity of 4.56 W/(m. K) could be achieved, which was 37.8% higher than that silicone paste using pure Vi-PDMS as the matrix. When TES-PDES-TMOS is used and filled with 900 parts (72.7 vol%) of hybrid AlN powders, the thermal conductivity of the silicone paste reaches 4.13 W/(m. K). Despite its thermal conductivity being only 3.5% higher relative to the silicone paste using only Vi-PDMS as the polymer matrix, its thermal resistance decreased by 20.3%. When TES-PDMS-TMOS is used and filled with 1200 parts (78.0 vol%) of hybrid AlN powders, the thermal conductivity of the silicone paste could reach up to 4.59 W/(m. K), together with a thermal resistance 29.6% lower than that of silicone paste where 1000 parts (74.7 vol%) of hybrid AlN particles filled in the Vi-PDMS. The heat dissipation of the 30 W high-brightness LED chip also illustrated the excellent thermal conductivities of these silicone pastes. The effect of another terminal group on the monotrimethoxysilylethyl-terminated asymmetric polysiloxanes on the thermal resistance of thermal interface materials was also discussed in detail.
研究领域:
材料科学
·
热管理技术
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Yijiao Zhang,Yanming Wang,Haiying Huo,Pu Zhang,Xiaoliang Zhang,Hongwei Che,Jingbo Mu,Zhixiao Zhang,Ping Li,Chunxia Wu
A 2D/1D/0D ternary heterostructure was fabricated that combined the accumulative merits of each component to exhibit superior performance through synergistic effects. This study adopted a strategy based on integrating 2D MXene, 1D tubular MnO 2 , and 0D Ag nanospheres into one electrode to obtain a ternary heterogeneous layered structure composite electrode. Utilizing the collaborative and intensive outcomes from MXene, MnO 2 , and Ag, the resulting MXene/MnO 2 /Ag composite electrode achieved an exemplary specific capacitance of 880.8 F g −1 at 2 A g −1 . In this study, an asymmetric supercapacitor (ASC) was developed and fabricated using the MXene/MnO 2 /Ag composite for the anode, commercial activated carbon as the cathode. Consequently, in a two-electrode setup, the resulting devices displayed an admirable specific capacitance of 112.5 F g −1 at 3 A g −1 . After being cycled 5000 times, the device maintained 85.0 % of its original capacitance under charge-discharge conditions. Furthermore, the ASC device demonstrated a pronounced energy density of 39.9 Wh g −1 during cycling with a corresponding power density of 2955.8 W kg −1 . These results showed that the dimensionally combined MXene/MnO 2 /Ag nanoarchitectonic electrodes offered considerable application potential for enhancing energy storage in supercapacitors.
研究领域:
材料科学
·
能源存储
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2018
·Vol. 148
·期 6
·1714-1722
·
IF 2.911
Luo Wei,Deng Xin-Xing,Huo Jiao,Ruan Tao,Gong Zhi-Wei,Yan Jia-Bao,Yang Zhong-Hua,Quan Can,Cui Zhi-Fang
Abstract Microalgae are excellent biocatalyst candidates for photo-biocatalytic-asymmetric reduction of prochiral ketones to produce enantiomer alcohols. In the biocatalysis asymmetric reduction of carbonyl group process, the cofactor, NADPH, plays a key role. So the current study focused on the effect of NADPH availability on the reduction. Photosynthesis is a main pathway for NADPH regeneration in microalgae, and the ferredoxin-NADP + oxidoreductase (FNR) is the key enzyme in this process. In this work, we constructed an engineered cyanobacterium Synechocystis sp. PCC6803:: Ω- P petE-petH to overexpress FNR gene petH to strengthen NADPH regeneration. The results show that the intracellular NADPH content was increased 80.8% compared to the wild type. Applying the Synechocystis sp. PCC6803:: Ω- P petE-petH to catalyze the model asymmetric reduction reaction (reduction of acetophenone to S -phenylethanol), the yield was improved 61.2% compared to the wild-type. This work makes the microalgal biocatalysis asymmetric reduction process become more preponderant via providing a new route to enhance the regeneration of cofactor NADPH. Graphical Abstract Putative metabolic process of nicotinamide adenine dinucleotide phosphate (NADPH) regeneration and the photo-biocatalytic-asymmetric reduction reaction of prochiral ketones in microalgal cells.
研究领域:
生物化学
·
合成生物学
✓ 已验证
DOI
高影响因子
PHYSICS OF FLUIDS
·
2024
·Vol. 36
·期 6
·
IF 4.1
Li Gu-Yuan,Yu Jia-Jia,Duan Cheng-Cheng,Sun Shouli,Wu Chun-Mei,Li You-Rong
In this work, efficient microfluidic flow rate tuning based on the asymmetric flow of nematic liquid crystal 5CB under a horizontal temperature gradient is studied. Rectangular microchannels with the width of 100 μ m are fabricated through soft lithography and treated with homeotropic surface anchoring conditions. Polarized optical microscopy is applied to explore the unique optical anisotropic characteristics of the nematic liquid crystal. The asymmetric velocity profiles in the microchannel are obtained by particle tracking velocimetry. The effects of temperature, flow rate, and aspect ratio on the velocity profile and split ratio of the asymmetric flow are quantitatively studied for the first time, while the mechanism of the flow asymmetry of the nematic liquid crystal is discussed. The results show that the asymmetric flow of the nematic liquid crystal occurs after the horizontal temperature gradient is applied, with the velocity in the heated region markedly higher than its counterpart. The split ratio of the asymmetric flow increases with the increase in the temperature gradient and the decrease in the flow rate. The aspect ratio influences the asymmetric flow through approaches of average velocity and surface anchoring strength, while the former is more distinct. The impacts of temperature gradient, flow rate, and aspect ratio on the flow asymmetry of nematic liquid crystals are caused by the coupling between physical properties, velocity field, and director field. Microchannels based on the asymmetric flow characteristics of nematic liquid crystals can act as a novel kind of temperature-controlled microvalve to achieve efficient microfluidic flow tuning.
研究领域:
物理学
·
微流控技术
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）