ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Shaoqiong Feng,Hanjun Chen,Ziao Hu,Tingting Wu,Zhihong Liu
MicroRNA (miRNA) is a promising biomarker for the diagnosis, monitoring, and prognostic evaluation of diseases, especially cancer. The existing miRNA detection methods usually need external instruments for quantitative signal output, limiting their practical applications in point-of-care (POC) settings. Here, we propose a distance-based biosensor through a responsive hydrogel, in combination with a CRISPR/Cas12a system and target-triggered strand displacement amplification (SDA) reaction for visual quantitative and sensitive measurement of miRNA. The target miRNA is first converted into plenty of double-stranded DNA (dsDNA) via target-triggered SDA reaction. Then, the dsDNA products trigger the collateral cleavage activity of CRISPR/Cas12a, leading to the release of trypsin from magnetic beads (MBs). The released trypsin can hydrolyze gelatin, and hence the permeability of gelatin-treated filter paper is increased, resulting in a visible distance signal on a cotton thread. Using this system, the concentration of the target miRNA can be quantified visually without any assistance of instruments, and a detection limit of 6.28 pM is obtained. In addition, the target miRNA in human serum samples and cell lysates can also be detected accurately. Owing to the characteristics of simplicity, sensitivity, specificity, and portability, the proposed biosensor provides a new tool for miRNA detection and holds great promise in POC applications.
研究领域:
生物技术
·
分子诊断
·
医学检验
✓ 已验证
DOI
PubMed
高影响因子
Chemistry-An Asian Journal
·
2021
·Vol. 16
·期 4
·348-354
·
IF 4.568
Shengju Zhou,Ying Sui,Xiaotong Zhu,Xiaofeng Sun,Shuping Zhuo,Hongguang Li
Graphical The multicolor emission CDs have been successfully prepared through a one-pot pyrolysis of citric acid in formamide. Then, the precipitation method, dialysis and GPC were successively employed to purify the multicolor emission CDs. Recent years have witnessed a rapid development of carbon dots (CDs), due to their outstanding luminescence properties and excellent biocompatibility. However, the internal structure and photoluminescent (PL) mechanism of CDs are still the subject of considerable debate, which is due to the fact that reaction products usually contain mixtures of several CD fractions as well as molecular intermediate and side products. Therefore, careful purification of the CDs is significant for analysis of structure and luminescence mechanism. Here, multicolor emission CDs were prepared by a one-pot pyrolysis of citric acid in formamide. Then, the precipitation method, dialysis and gel permeation chromatography (GPC) are successively employed to purify the multicolor emission CDs. This post-treatment allowed us to compare the optical properties of CDs obtained by different separation methods and provide a valuable guidance for the purification of CDs.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER
·
2022
·
IF 4.432
Mei Hong,Wei Liu,Yonggang Liu,Xuemin Dai,Yu Kang,Rui Li,Feng Bao,Xuepeng Qiu,Yanxiong Pan,Xiangling Ji
Polyamic acid (PAA) is the precursor of polyimide (PI) prepared by a two-step method, its molecular weight and molecular weight distribution not only play an important role during the preparation and processing, but also influence the final performance of PI. However, precise characterization on molecular weight of PAA is still a challenge because of the existence of very complicated interactions in the solution system, including the electrostatic interaction , hydrogen bond interaction, dipole-dipole interaction, etc . Thus, it is necessary to establish a suitable strategy which can completely suppress these complex effects and get reasonable data on molecular weight. Herein, the gel permeation chromatography (GPC) coupled with differential refractive index (RI) and multi-angle laser light scattering (MALLS) detectors were applied to measure the molecular weight of (6FDA-DMB) PAA using different mobile phases , LiBr/DMF, LiBr/H 3 PO 4 /THF/DMF, LiBr/HAc/THF/DMF, and LiBr/HAc/DMF, respectively. It was found that combination of LiBr with HAc can shield the above-mentioned complex interactions and is more conducive to the separation of PAA than only addition of LiBr in DMF. LiBr/HAc/DMF was employed for the first time as a mild mobile phase to effectively separate PAA and determine its molecular weight. After a series of conditional experiments, 0.02 M LiBr/0.2 M HAc/DMF was fixed as an optimized mobile phase to measure the relative and absolute molecular weights of (6FDA-DMB) PAA prepared, and the obtained M w from GPC-MALLS and GPC-RI were 35,300 g/mol and 125,000 g/mol, respectively. Particularly, such a mobile phase is also applicable to other PAA samples with different structures, and the final results on molecular weight are also reproducible.
研究领域:
高分子化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Guoqing An,Hongli Liu,Hongyan Li,Zhong Chen,Jing Li,Yajing Li
The SiBCN ceramic aerogel/graphene composites were synthesized by combining a simple sol-gel infiltration process with CO 2 supercritical drying technology and polymer-derived ceramics route. In order to select the best preceramic sample for sintering, the micromorphology of PSNB aerogel/graphene composites fabricated with different graphene oxide solution concentrations were investigated. The microstructure evolution of the prepared SiBCN ceramic aerogel/graphene composites and phase composition were studied by SEM, TEM and XRD , the pore structure of the preceramic composites pyrolyzed at 1200 °C was tested by specific surface area and pore size analyzer. Furthermore, the compressive strain-stress curve and toughening mechanisms of composites were also investigated in detail. The results showed that all the preceramic composites and obtained ceramic aerogel composites possessed the mesoporous structure. The basic structure of SiBCN aerogel network changed from the initial spherical particles accumulation to the nanowires lapping with the sintering temperature increased from 800 °C to 1200 °C. After pyrolyzing at 1200 °C, the specific surface area and pore volume for the sample were 101.61 m 2 g −1 and 1.43 cm 3 g −1 , respectively, and a small amount of β-SiC crystalline phases were formed in amorphous ceramic matrix and had an relatively uniform distribution. Moreover, the paepared ceramic aerogel composites possessed a certain degree of toughness, the toughening mechanisms of composite samples mainly included the crack deflection, graphene pull-out, graphene bridging and graphene crumpling.
研究领域:
材料科学
·
陶瓷材料
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2019
·
IF 3.206
Xiang-Dong Qing,Huai-Bo Zhou,Xiao-Hua Zhang,Hai-Long Wu,Chang-Ya Chen,Su-Wen Xu,Shuang-Shuang Li
Polycyclic aromatic hydrocarbons (PAHs) are of worldwide environmental concern because of their properties of carcinogenicity, mutagenicity and teratogenicity. In the work, a smart combination of gel permeation chromatography-diode array detector and second-order calibration based on alternating trilinear decomposition (ATLD-GPC-DAD) is proposed for simultaneous targeted identification and quantification of 15 PAHs in atmospheric pollution sources such as flue-dust and greasy-dirt samples. No need of tedious sample pretreatment and specific PAHs separation column, severely overlapped chromatograph peaks are successfully resolved by the ATLD-GPC-DAD method even with only 3 s of difference in retention times. Accurate quantitative results of 15 PAHs are achieved by using the developed method even in the presence of unexpected interferents. The limits of detection range from 0.94 ng mL −1 to 48.86 ng mL −1 , and the average recoveries are in the range of (81.2 ± 1.0)% to (108.9 ± 11.6)% for flue-dust samples and (89.7 ± 3.4)% to (107.5 ± 8.0)% for greasy-dirt samples. The sensitivity and selectivity of analytes is significantly improved with the aid of “mathematical separation” of the method. These results indicate that it opens a promising analytical strategy for control of PAHs emissions and management of urban air quality.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
BULLETIN OF THE KOREAN CHEMICAL SOCIETY
·
2016
·Vol. 37
·期 12
·1955-1960
·
IF 0.793
Xiaoping Chang,Zequan Liu,Qiang Zhang
The samples of sodium salt of methacrylic acid/acrylic acid-2-isooctyl ester/2-acrylamido-2-methylpropanesulfonic acid terpolymer (SSMAA) were synthesized by free radical solution polymerization. The absolute weight-average molar mass ( M w ) and polydispersity ( M w / M n ) of the polymers were successfully determined using aqueous-based gel permeation chromatography coupled with multiangle laser light scattering. The results show that mixed solutions of highly concentrated buffered salt (NaNO 3 or NaCl and NaH 2 PO 4 ) and organic solvent modifier (methanol) are needed to eliminate the undesirable interactions between polymer and polymer, and between polymer and stationary phase. Dynamic light scattering was first used to investigate the aggregation behavior of SSMAA in a variety of potential mobile phase compositions and screen the optimum compositions. The M w and M w / M n values of the three samples prepared with different amount of initiator are 13500, 5820, and 2490 g/mol and 1.52, 1.45, and 1.47, respectively.
研究领域:
化学
·
高分子科学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2020
·
IF 5.162
Danli Wang,Furong Hou,Xiaobin Ma,Weijun Chen,Lufeng Yan,Tian Ding,Xingqian Ye,Donghong Liu
Enzymatic hydrolysis of starch is an important process in the food industry. In the present work, ultrasound was introduced in glucoamylase pretreatment, starch pretreatment and mixed reaction system treatment to enhance starch hydrolysis efficiency. These different processes were studied to explore the mechanism of ultrasound in promoting enzymatic reactions. The hydrolysis degree of starch was determined via measuring the reducing sugar yield. Ultrasound caused enzyme inactivation under high temperatures, high ultrasonic power and long-time treatment, especially at high temperatures exceeding 65 °C. Ultrasound pretreatment of starch before enzymolysis led to the furtherance of starch hydrolysis degree. Meanwhile, sonicating the mixed enzymatic reaction system below 65 °C promoted starch hydrolysis significantly, inducing more than five- fold growth in the degree of starch hydrolysis as much as the ultrasound pretreatment caused. Molecular weights analysis conducted by the MALLS system reflected the enormous damage of starch molecules caused by ultrasound. The amylose contents and chain length distributions of samples were separately analyzed by iodine binding method and size exclusion chromatography. The results of the two experiments illustrate that ultrasound could promote the enzymatic hydrolysis of amylopectin, which is harder for glucoamylase to hydrolyze compared to amylose.
研究领域:
食品科学
·
生物技术
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2019
·
IF 3.78
Qun Liu,Haipeng Wang,Lei Chen,Wulong Li,Yakun Zong,Yi Sun,Zhanxiong Li
Fluorinated Poly(ε-caprolactone) (PCL) block copolymers PCL-PTFOA(2 h), PCL-PTFOA(4 h), PCL-PTFOA(6 h), PCL-PTFOA(8 h) were prepared via esterification by using poly(1H,1H,2H,2H-perfluorooctylacrylate) (PTFOA) with different molecular weights as reactants. It was found that PCL-PTFOA(6 h) and PCL-PTFOA(8 h) possessed the similar molecular weight via GPC analysis. PCL and fluorinated PCL block copolymers films were prepared by solution casting method. The structure and properties of film surface of the fluorinated PCL block copolymers were analyzed by energy dispersive X-ray spectrometer (EDS), scanning electron microscope (SEM), Differential scanning calorimetry (DSC), water contact angles (WCAs) and the surface free energy. The results showed that the fluorinated PCL films possessed improved hydrophobicity because of the microphase separation between fluoropolymer chain and PCL chain. The enzymatic degradation of PCL, PCL-PTFOA(2 h), PCL-PTFOA(4 h) and PCL-PTFOA(6 h) films were performed at 37 °C in a phosphate buffer solution (PBS, 0.1 M, with a pH of 7.2–7.4) with lipase and analyzed by weight loss, SEM and EDS . It was found that the introduction of fluorine-containing segment reduced the rate of enzymatic degradation of the copolymer film in the early period, while increased the finally weight loss rate with a prolonged time. In addition, the enzymatic degradation rate of PCL-PTFOA(2 h) film and PCL-PTFOA(4 h) film was faster than that of PCL-PTFOA(6 h) film.
研究领域:
高分子科学
·
材料科学
·
生物降解
·
表面化学
✓ 已验证
产品关联
DOI
高影响因子
Food & Function
·
2020
·Vol. 11
·期 9
·7576-7583
·
IF 4.171
Qiu Li,Fenfang Yang,Ranran Hou,Tingting Huang,Zhihui Hao
We extracted and purified three polysaccharides from Echinacea purpurea using pectinase-assisted extraction to obtain crude preparations and optimized the method using an orthogonal analysis. We obtained three polysaccharide fractions (EPPS-1, -2 and -3) using DEAE ion exchange and gel filtration chromatography. The homogeneity of the fractions was confirmed using high performance gel permeation chromatography. EPPS-3 administered to mice in a LPS-induced septicemia model effectively counteracted the effects of LPS resulting in significantly less lung damage. This trend was also seen in the serum and lung cytokine levels where EPPS-3 significantly decreased the levels of TNF-α and IL-6 and increased IL-10. Particularly, we fully characterized the structure of the EPPS-3 polysaccharide using a series of technologies. This polysaccharide structure was mainly composed of →4)-α-Glcp-(1→, →4)-α-Galp-(1→, T-α-Araf-(1→, →3,4)-β-GalpA-(1→ glycosidic linkages at a certain proportion. In sum, EPPS-3, with a clear structure, has potent anti-inflammatory activities and is a candidate for further development as an anti-inflammatory agent for clinical development.
研究领域:
药理学
·
免疫学
·
植物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2019
·
IF 6.97
Guanhua Wang,Xiaoqian Liu,Bo Yang,Chuanling Si,Ashak Mahmud Parvez,Jinmyung Jang,Yonghao Ni
Lignin heterogeneity, involving complex structure and high polydispersity, is a key challenge that restricts its value-added applications. Fractionation of heterogeneous lignin into several homogeneous subdivisions is an attractive and practical strategy to overcome this limitation. In this work, γ-valerolactone (GVL), a sugar-derived product, was used as a green solvent for lignin fractionation when mixed with water. The enzymatic hydrolysis lignin (EHL) was subdivided into three different fractions (F1, F2, and F3) by dissolving it completely in 60% aqueous GVL and then following gradient precipitation in 40%, 30%, and 5% aqueous GVL solutions, sequentially. Detailed characterization techniques were conducted to provide a comprehensive evaluation of the three obtained lignin fractions. Moreover, the proposed fractionation mechanism was further investigated on the basis of Kamlet–Taft parameters. The gel permeation chromatography (GPC) analyses showed that the three fractions presented lower polydispersity than the parent EHL and, furthermore, a gradual decreasing molecular weight due to the different solubility of various molecular weight lignins in aqueous GVL solvents. The structural analyses revealed that with the decrease of molecular weight, the guaiacyl unit content in lignin fractions decreased, with significant increases of functional groups (i.e., aromatic/aliphatic hydroxyl and carboxyl groups). The solvent recycling study showed that the aqueous GVL had a high recovery, and the recycled GVL had the same lignin fractionation performance as fresh GVL. Overall, compared with traditional fractionation using multiple organic solvents, the present work provides a green and efficient route to fractionate lignin and, therefore, significantly decreases its molecular weight polydispersity and structural heterogeneity.
研究领域:
化学工程
·
材料科学
·
绿色化学
·
生物技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
·
2018
·Vol. 56
·期 7
·699-704
·
IF 2.588
Lin Lei,Feifei Li,Haixiu Zhao,Yuntao Wang
We successfully synthesized poly( l -lactide)- b -poly (methyl methacrylate) diblock copolymers at ambient temperature by combining ultraviolet light-induced copper-catalyzed ATRP and organo-catalyzed ring-opening polymerization (ROP) in one-pot. The polymerization processes were carried out by three routes: one-pot simultaneous ATRP and ROP, one-pot sequential ATRP followed by ROP, and one-pot sequential ROP followed by ATRP. The structure of the block copolymers is confirmed by nuclear magnetic resonance and gel permeation chromatography, which suggests that the polymerization method is facile and attractive for preparing block copolymers. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56 , 699–704
研究领域:
高分子科学
·
材料化学
✓ 已验证
产品关联
DOI
高影响因子
FOOD RESEARCH INTERNATIONAL
·
2023
·
IF 8.1
Jingna Yan,Anxia Lu,Jirui Kun,Bei Wang,Yiwen Miao,Yingjuan Chen,Chi-Tang Ho,Qing Meng,Huarong Tong
Tea infected with bird’s eye spot disease generally imparts a long-lasting bitter taste, which is unacceptable to most consumers. This study has comprehensively evaluated the taste profiles of infected and healthy teas and investigated their known bitter compounds previously reported in tea. Quantification analyses and calculation of dose-over-threshold (DoT) factors revealed that no obvious difference was visualized in catechins, caffeine, bitter amino acids, and flavonols and their glycosides between infected and healthy tea samples, which was also verified by principal component analysis (PCA) and hierarchical cluster analysis (HCA). Therefore, these known bitter compounds have been ruled out as critical contributors to the long-lasting bitterness of infected teas. Furthermore, Gel permeation chromatography, sensory analysis, and UPLC-Q-TOF-MS were employed and identified 13 substances from the target bitter fractions, including caffeine, ten triterpenoids, and two oxylipins. The higher triterpenoid levels were supposed to be the reason causing the long-lasting bitterness. This study has provided a research direction for the molecular basis of the long-lasting bitterness of infected tea leaves with bird’s eye spot disease.
研究领域:
食品科学
·
化学
·
植物病理学
·
感官科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）