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118 result(s) for "Chen, Qinhua"
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Online photochemical derivatization enables comprehensive mass spectrometric analysis of unsaturated phospholipid isomers
Mass spectrometry-based lipidomics is the primary tool for the structural analysis of lipids but the effective localization of carbon–carbon double bonds (C=C) in unsaturated lipids to distinguish C=C location isomers remains challenging. Here, we develop a large-scale lipid analysis platform by coupling online C=C derivatization through the Paternò-Büchi reaction with liquid chromatography-tandem mass spectrometry. This provides rich information on lipid C=C location isomers, revealing C=C locations for more than 200 unsaturated glycerophospholipids in bovine liver among which we identify 55 groups of C=C location isomers. By analyzing tissue samples of patients with breast cancer and type 2 diabetes plasma samples, we find that the ratios of C=C isomers are much less affected by interpersonal variations than their individual abundances, suggesting that isomer ratios may be used for the discovery of lipid biomarkers. Mass spectrometry is widely used for large-scale lipid profiling but distinguishing unsaturated lipid isomers is still challenging. Here, the authors present an analytical platform for high-throughput identification of lipid C=C location isomers in clinical samples, showing that isomer ratios may guide biomarker discovery.
Large-scale lipid analysis with C=C location and sn-position isomer resolving power
Lipids play a pivotal role in biological processes and lipid analysis by mass spectrometry (MS) has significantly advanced lipidomic studies. While the structure specificity of lipid analysis proves to be critical for studying the biological functions of lipids, current mainstream methods for large-scale lipid analysis can only identify the lipid classes and fatty acyl chains, leaving the C=C location and sn -position unidentified. In this study, combining photochemistry and tandem MS we develop a simple but effective workflow to enable large-scale and near-complete lipid structure characterization with a powerful capability of identifying C=C location(s) and sn -position(s) simultaneously. Quantitation of lipid structure isomers at multiple levels of specificity is achieved and different subtypes of human breast cancer cells are successfully discriminated. Remarkably, human lung cancer tissues can only be distinguished from adjacent normal tissues using quantitative results of both lipid C=C location and sn -position isomers. Coupling photochemical derivatization with tandem mass spectrometry enables C=C-isomer resolved lipidomics. Here, the authors further develop this approach into a shotgun lipidomics workflow that allows simultaneous characterization of lipid C=C locations and sn -positions in complex biological samples.
CRISPR/Cas12a Coupling with Magnetic Nanoparticles and Cascaded Strand Displacement Reaction for Ultrasensitive Fluorescence Determination of Exosomal miR-21
Exosomal MicroRNA-21 (miRNA-21, miR-21) is significantly up-regulated in blood samples of patients with lung cancer. Exosomal-derived miR-21 can be used as a promising biomarker for the early diagnosis of lung cancer. This paper develops a fluorescent biosensor based on the combination of magnetic nanoparticles (MNPs), cascade strand displacement reaction (CSDR) and CRISPR/Cas12a to detect the exosomal miR-21 from lung cancer. The powerful separation performance of MNPs can eliminate the potential interference of matrix and reduce the background signal, which is very beneficial for the improvement of specificity and sensitivity. The CSDR can specifically transform one miR-21 into plenty of DNA which can specifically trigger the trans-cleavage nuclease activity of Cas12a, resulting in the cleavage of ssDNA bi-labeled with fluorescent and a quencher. Under the optimized experimental conditions, the developed fluorescence biosensor exhibited high sensitivity and specificity towards the determination of exosomal-derived miR-21 with a linear range from 10 to 1 × 105 fM and a low detection limit of about 0.89 fM. Most importantly, this method can be successfully applied to distinguish the exosomal miR-21 from the lung cancer patients and the healthy people.
Assembly and Annotation of a Draft Genome of the Medicinal Plant Polygonum cuspidatum
(Japanese knotweed, also known as Huzhang in Chinese), a plant that produces bioactive components such as stilbenes and quinones, has long been recognized as important in traditional Chinese herbal medicine. To better understand the biological features of this plant and to gain genetic insight into the biosynthesis of its natural products, we assembled a draft genome of using Illumina sequencing technology. The draft genome is ca. 2.56 Gb long, with 71.54% of the genome annotated as transposable elements. Integrated gene prediction suggested that the genome encodes 55,075 functional genes, including 6,776 gene families that are conserved in the five eudicot species examined and 2,386 that are unique to . Among the functional genes identified, 4,753 are predicted to encode transcription factors. We traced the gene duplication history of and determined that it has undergone two whole-genome duplication events about 65 and 6.6 million years ago. Roots are considered the primary medicinal tissue, and transcriptome analysis identified 2,173 genes that were expressed at higher levels in roots compared to aboveground tissues. Detailed phylogenetic analysis demonstrated expansion of the gene family encoding stilbene synthase and chalcone synthase enzymes in the phenylpropanoid metabolic pathway, which is associated with the biosynthesis of resveratrol, a pharmacologically important stilbene. Analysis of the draft genome identified 7 abscisic acid and water deficit stress-induced protein-coding genes and 14 cysteine-rich transmembrane module genes predicted to be involved in stress responses. The draft genome assembly produced in this study represents a valuable resource for the molecular characterization of medicinal compounds in , the improvement of this important medicinal plant, and the exploration of its abiotic stress resistance.
Highly sensitive electrochemical determination of rutin based on the synergistic effect of 3D porous carbon and cobalt tungstate nanosheets
Rutin, a flavonoid found in fruits and vegetables, is a potential anticancer compound with strong anticancer activity. Therefore, electrochemical sensor was developed for the detection of rutin. In this study, CoWO4 nanosheets were synthesized via a hydrothermal method, and porous carbon (PC) was prepared via high-temperature pyrolysis. Successful preparation of the materials was confirmed, and characterization was performed by transmission electron microscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy. A mixture of PC and CoWO4 nanosheets was used as an electrode modifier to fabricate the electrochemical sensor for the electrochemical determination of rutin. The 3D CoWO4 nanosheets exhibited high electrocatalytic activity and good stability. PC has a high surface-to-volume ratio and superior conductivity. Moreover, the hydrophobicity of PC allows large amounts of rutin to be adsorbed, thereby increasing the concentration of rutin at the electrode surface. Owing to the synergistic effect of the 3D CoWO4 nanosheets and PC, the developed electrochemical sensor was employed to quantitively determine rutin with high stability and sensitivity. The sensor showed a good linear range (5–5000 ng/mL) with a detection limit of 0.45 ng/mL. The developed sensor was successfully applied to the determination of rutin in crushed tablets and human serum samples. [Display omitted] •Highly sensitive electrochemical sensor based on 3D porous carbon and CoWO4 nanosheets.•Electrochemical signal of rutin is mainly based on its concentration at the electrode surface.•The introduction of porous carbon improved the electrochemical performance of 3D CoWO4.•The sensor was successfully applied to determine rutin in human serum samples.
ZIF‐8 Selective Dispersive Solid‐Phase Extraction‐LC‐MS/MS Method for the Determination of Aconitine alkaloids in Rat Plasma: Application in Pharmacokinetic Studies
Objective: Aconitine alkaloids, as the principal bioactive constituents of Fuzi, pose a significant challenge to its clinical application due to their toxicity. This study aimed to establish a rapid, efficient, and stable method for quantifying monoester‐type and diester‐type alkaloids in raw Fuzi using zeolitic imidazolate framework‐8 (ZIF‐8). The method was subsequently applied to pharmacokinetic studies in rats, offering valuable insights into the safe clinical use of Fuzi. Methods: Synthetic ZIF‐8 was employed as the microextraction adsorbent, with optimization of extraction parameters such as ZIF‐8 content, shaker speed, extraction time, and sodium ion concentration to maximize enrichment efficiency. A dispersive solid‐phase extraction–liquid chromatography–tandem mass spectrometry (d‐SPE–LC–MS/MS) method, based on ZIF‐8, was developed and validated for method performance. The pharmacokinetics of five aconitine alkaloids in Fuzi were investigated, ensuring efficient extraction and analysis. Results: Under the optimized conditions, the d‐SPE method demonstrated robust enrichment of aconitine alkaloids. A strong linear relationship was established for aconitine, hypaconitine, mesaconitine, lappaconitine, and benzoylaconitine within the concentration range of 0.3125–1000 ng/mL, with correlation coefficients exceeding 0.99. The LC–MS/MS assay achieved a detection limit as low as 0.104 ng/mL. Additionally, the pharmacokinetic analysis revealed rapid absorption of the five alkaloids, with benzoylaconitine exhibiting a T max of 0.25 h. Conclusion: This study introduces a novel d‐SPE–LC–MS/MS method based on ZIF‐8 for the analysis of aconitine alkaloids in plasma, facilitating pharmacokinetic studies of Fuzi. These findings substantially contribute to a deeper understanding of the in vivo pharmacokinetics of aconitine alkaloids.
CSDR Coupling with Exo III for Ultrasensitive Electrochemistry Determination of miR-145
Recently, miRNAs have become a promising biomarker for disease diagnostics. miRNA-145 is closely related to strokes. The accuracy determination of miRNA-145 (miR-145) in stroke patients still remains challenging due to its heterogeneity and low abundance, as well as the complexity of the blood matrix. In this work, we developed a novel electrochemical miRNA-145 biosensor via subtly coupling the cascade strand displacement reaction (CSDR), exonuclease III (Exo III), and magnetic nanoparticles (MNPs). The developed electrochemical biosensor can quantitatively detect miRNA-145 ranging from 1 × 102 to 1 × 106 aM with a detection limit as low down as 100 aM. This biosensor also exhibits excellent specificity to distinguish similar miRNA sequences even with single-base differences. It has been successfully applied to distinguish healthy people from stroke patients. The results of this biosensor are consistent with the results of the reverse transcription quantitative polymerase chain reaction (RT-qPCR). The proposed electrochemical biosensor has great potential applications for biomedical research on and clinical diagnosis of strokes.
Systematic Qualitative and Quantitative Analyses of Wenxin Granule via Ultra-High Performance Liquid Chromatography Coupled with Ion Mobility Quadrupole Time-of-Flight Mass Spectrometry and Triple Quadrupole–Linear Ion Trap Mass Spectrometry
Wenxin granule (WXG) is a popular traditional Chinese medicine (TCM) preparation for the treatment of arrhythmia disease. Potent analytical technologies are needed to elucidate its chemical composition and assess the quality differences among multibatch samples. In this work, both a multicomponent characterization and quantitative assay of WXG were conducted using two liquid chromatography–mass spectrometry (LC-MS) approaches. An ultra-high performance liquid chromatography–ion mobility quadrupole time-of-flight mass spectrometry (UHPLC/IM-QTOF-MS) approach combined with intelligent peak annotation workflows was developed to characterize the multicomponents of WXG. A hybrid scan approach enabling alternative data-independent and data-dependent acquisitions was established. We characterized 205 components, including 92 ginsenosides, 53 steroidal saponins, 14 alkaloids, and 46 others. Moreover, an optimized scheduled multiple reaction monitoring (sMRM) method was elaborated, targeting 24 compounds of WXG via ultra-high performance liquid chromatography–triple quadrupole linear ion trap mass spectrometry (UHPLC/QTrap-MS), which was validated based on its selectivity, precision, stability, repeatability, linearity, sensitivity, recovery, and matrix effect. By applying this method to 27 batches of WXG samples, the content variations of multiple markers from Notoginseng Radix et Rhizoma (21) and Codonopsis Radix (3) were depicted. Conclusively, we achieved the comprehensive multicomponent characterization and holistic quality assessment of WXG by targeting the non-volatile components.
Characterization of ginsenosides from Panax japonicus var. major (Zhu-Zi-Shen) based on ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometry and desorption electrospray ionization-mass spectrometry imaging
Background Panax japonicus var. major (PJM) belongs to the well-known ginseng species used in west China for hundreds of years, which has the effects of lung tonifying and yin nourishing, and exerts the analgesic, antitussive, and hemostatic activities. Compared with the other Panax species, the chemical composition and the spatial tissue distribution of the bioactive ginsenosides in PJM have seldom been investigated. Methods Ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC/QTOF-MS) and desorption electrospray ionization-mass spectrometry imaging (DESI-MSI) were integrated for the systematic characterization and spatial tissue distribution studies of ginsenosides in the rhizome of PJM. Considering the great difficulty in exposing the minor saponins, apart from the conventional Auto MS/MS ( M1 ), two different precursor ions list-including data-dependent acquisition (PIL-DDA) approaches, involving the direct input of an in-house library containing 579 known ginsenosides ( M2 ) and the inclusion of the target precursors screened from the MS 1 data by mass defect filtering ( M3 ), were developed. The in situ spatial distribution of various ginsenosides in PJM was profiled based on DESI-MSI with a mass range of m/z 100–1500 in the negative ion mode, with the imaging data processed by the High Definition Imaging (HDI) software. Results Under the optimized condition, 272 ginsenosides were identified or tentatively characterized, and 138 thereof were possibly not ever reported from the Panax genus. They were composed by 75 oleanolic acid type, 22 protopanaxadiol type, 52 protopanaxatriol type, 16 octillol type, 19 malonylated, 35 C-17 side-chain varied, and 53 others. In addition, the DESI-MSI experiment unveiled the differentiated distribution of saponins, but the main location in the cork layer and phloem of the rhizome. The abundance of the oleanolic acid ginsenosides was high in the rhizome slice of PJM, which was consistent with the results obtained by UHPLC/QTOF-MS. Conclusion Comprehensive characterization of the ginsenosides in the rhizome of PJM was achieved, with a large amount of unknown structures unveiled primarily. We, for the first time, reported the spatial tissue distribution of different subtypes of ginsenosides in the rhizome slice of PJM. These results can benefit the quality control and further development of PJM and the other ginseng species.
Head-to-Head Comparison of Sirolimus-Eluting Stents versus Paclitaxel-Eluting Stents in Patients Undergoing Percutaneous Coronary Intervention: A Meta-Analysis of 76 Studies
The relative short-, long- and overall-term efficacy and safety of sirolimus-eluting stents (SES, Cypher) compared with paclitaxel-eluting stents (PES, Taxus) in large head-to-head comparisons still remain to be defined. We searched Pubmed, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) for articles comparing outcomes of interest between SES and PES without language restriction. Short- (≤ 1 year), long- (>1 year), and overall-term (the longest follow-up of each study) outcomes were evaluated. The primary endpoint was target lesion revascularization (TLR). Other outcomes of interest were target vessel revascularization (TVR), myocardial infarction, all-cause death, cardiac death, stent thrombosis, major adverse cardiac events (MACEs), restenosis and late lumen loss. Seventy-six studies including more than 15000 patients in randomized controlled trials and over 70000 patients in adjusted observational studies were included. At overall-term follow-up, SES significantly reduced TLR (relative risk [RR]: 0.61; 95% confidence interval [CI]: 0.49-0.76), TVR (RR: 0.67; 95% CI: 0.54-0.83), MACE (RR: 0.79; 95% CI: 0.72-0.87), myocardial infarction (RR: 0.85; 95% CI: 0.73-0.99), in-segment restenosis (RR: 0.50; 95% CI: 0.38-0.65), and in-segment late lumen loss (weighted mean difference [WMD]: -0.19; 95% CI: -0.24--0.14) in randomized controlled trials compared with PES. In addition, lower rates of death (RR: 0.91; 95% CI: 0.83-1.00), any stent thrombosis (RR: 0.62; 95% CI: 0.45-0.86), definite stent thrombosis (RR: 0.59; 95% CI: 0.45-0.77) were found in patients receiving SES in adjusted observational studies. Largely similar results were found at short- and long-term follow-up, and in patients with diabetes, acute myocardial infarction or long lesions. SES significantly reduced the short-, long- and overall-term risk of TLR/TVR, MACE, and restenosis, and overall-term risk of myocardial infarction in randomized controlled trials, as compared with PES. Lower rates of death and stent thrombosis were also observed in observational studies in SES-treated patients.