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A high‐speed darkfield microscope has been developed to monitor the rapid rotation of single gold nanorods (AuNRs) and used to study the spatiotemporal heterogeneity of chemical reactions in free solution. A wide range of viscosities from 237 cP to 0.8 cP could be detected conveniently. We studied H2O2 decomposition reactions that were catalyzed by AuNRs coated with Pt nanodots (AuNR@PtNDs) and observed two different rotational states. The two states and their transitions are related to the production and the amalgamation of O2 nanobubbles on the nanorod surface depending on H2O2 concentration. In addition, the local fluidic environment of pure water was found to be non‐uniform in time and space. This technique could be applied to study other chemical and biochemical reactions in solution. [ABSTRACT FROM AUTHOR]

A high‐speed darkfield microscope has been developed to monitor the rapid rotation of single gold nanorods (AuNRs) and used to study the spatiotemporal heterogeneity of chemical reactions in free solution. A wide range of viscosities from 237 cP to 0.8 cP could be detected conveniently. We studied H2O2 decomposition reactions that were catalyzed by AuNRs coated with Pt nanodots (AuNR@PtNDs) and observed two different rotational states. The two states and their transitions are related to the production and the amalgamation of O2 nanobubbles on the nanorod surface depending on H2O2 concentration. In addition, the local fluidic environment of pure water was found to be non‐uniform in time and space. This technique could be applied to study other chemical and biochemical reactions in solution. [ABSTRACT FROM AUTHOR]

Unsaturated fatty acids (FAs) serve as nutrients, energy sources, and signaling molecules for organisms, which are the major components for a large variety of lipids. However, structural characterization and quantitation of unsaturated FAs by mass spectrometry remain an analytical challenge. Here, we report the coupling of epoxidation reaction of the C‗C in unsaturated FAs and tandem mass spectrometry (MS) for rapid and accurate identification and quantitation of C‗C isomers of FAs in a shotgun lipidomics approach. Epoxidation of the C‗C leads to the production of an epoxide which, upon collision induced dissociation (CID), produces abundant diagnostic ions indicative of the C‗C location. The total intensity of the same set of diagnostic ions for one specific FAC‗C isomer was also used for its relative and absolute quantitation. The simple experimental setup, rapid reaction kinetics (<2 min), high reaction yield (>90% for monounsaturated FAs), and easy-to-interpret tandem MS spectra enable a promising methodology particularly for the analysis of unsaturated FAs in complex biological samples such as human plasma and animal tissues. [ABSTRACT FROM AUTHOR]

α‐Synuclein is a central player in Parkinson's disease (PD) pathology. Various point mutations in α‐synuclein have been identified to alter the protein‐phospholipid binding behavior and cause PD. Therefore, exploration of α‐synuclein‐phospholipid interaction is important for understanding the PD pathogenesis and helping the early diagnosis of PD. Herein, a phospholipid‐decorated liquid crystal (LC)‐aqueous interface is constructed to investigate the binding between α‐synucleins (wild‐type and six familial mutant A30P, E46K, H50Q, G51D, A53E and A53T) and phospholipid. The application of deep learning analyzes and reveals distinct LC signatures generated by the binding of α‐synuclein and phospholipid. This system allows for the identification of single point mutant α‐synucleins with an average accuracy of 98.3±1.3% in a fast and efficient manner. We propose that this analytical methodology provides a new platform to understand α‐synuclein‐lipid interactions, and can be potentially developed for easy identification of α‐synuclein mutations in common clinic. [ABSTRACT FROM AUTHOR]

Skeletal muscle tissue is composed of various muscle cell types which differ in physiological functions. Changes in cell type composition of skeletal muscle are associated with the development of metabolic diseases. Skeletal muscle cell types are currently distinguished by immunofluorescence (IF) staining based on myosin heavy chain (MHC) isoform difference. However, it remains a challenge to provide metabolic fingerprints of different muscle cell types by IF staining. Therefore, in this study, we proposed a method to examine metabolite distribution within different cell types by time-of-flight secondary ion mass spectrometry (TOF-SIMS) with high spatial resolution. Skeletal muscle samples from C57/BL6 mice were obtained by slicing. Cell types in TOF-SIMS images were labelled corresponding to IF images from the same region of serially cut sections. Mass spectra corresponding to individual muscle cells were extracted to compare metabolic fingerprints among cell types. Skeletal muscle cells were classified into two clusters based on the mass spectra of individual cells. Unsaturated diacylglycerol (DG) and fatty acid (FA) species were found to be distributed in a cell-type dependent manner. Moreover, relative quantification showed that the content of unsaturated DGs, oleic acid and linoleic acid was higher in type I and type IIA cells than in type IIB cells. TOF-SIMS in combination with IF enables us to directly visualize metabolite distribution in different cell types, to find potential biomarkers for cell type classification. TOF-SIMS imaging coupled with IF staining has been proved to be a promising tool for metabolic fingerprinting of different skeletal muscle cell types. [ABSTRACT FROM AUTHOR]

Some anticarcinogen could treat cancers through regulating the synthesis and degradation of proteins. Therefore, the rules of newly synthesized proteins would be used to evaluate the effect of anticarcinogen. In this study, we coupled noncanonical amino acid tagging with click reaction to label the newly synthesized proteins in normal cells and cancerous cells. We studied the influence of six different drugs on the protein synthesis. The results showed the differences of protein synthesis rate and spatial distribution in normal cells and cancerous cells, as well as their different responding to anticarcinogen stimulation. This approach could help us to understand the growth of proteins and distinguish cancerous cells from normal cells, which would benefit the diagnosis and monitoring of cancer, as well as evaluating the curative effect of drugs. Based on this strategy, more significant biological process about newly synthesized biomolecules would be studied in-depth. [ABSTRACT FROM AUTHOR]

NK cell-mediated immunotherapy has received increasing attention in the past decade due to its efficacy and bio-safety. The composition and content of lipids in individual cells are closely related to NK cell-mediated cytotoxicity, especially polyunsaturated fatty acids (PUFA) which are oxidized during NK cell-mediated apoptosis. Here we investigated the changes of lipids in single HepG2 cells by label-free mass cytometry and obtained information on 53 lipids and 13 oxidized lipids after the interaction with NK92 MI cells. We found that the contents of lipids and oxidized lipids of HepG2 cells changed obviously during the NK cell-mediated apoptosis. The HepG2 cells could be classified into two phenotypes after co-culturing with NK92 MI cells based on the ratio of PC(38:6-2OH)/PC(38:6) in individual cells, which may serve as a feature to evaluate NK cell-mediated cytotoxicity. The present work used the lipids and oxidized lipids of individual cells to reveal the heterogeneity in NK cell-mediated apoptosis which would be a powerful method for evaluating the cytotoxicity of NK cells at the single-cell level. [ABSTRACT FROM AUTHOR]

The Zhusileng-Hangwula tectonic zone, located in the northern Alxa area, is a key site for understanding the evolution of the Paleo-Asian Ocean (PAO) and related mineral formation. We report the major and trace elements and zircon U-Pb ages of newly discovered mafic and intermediate to felsic intrusive rocks in the Zhusileng area. LA-ICP-MS zircon U-Pb analyses of the Echenghei diabase and Haierhan and Heipingshan granites yielded crystallization ages of 305 Ma, 284 Ma, and 271 Ma, respectively. The Late Carboniferous mafic rocks have high MgO and Fe2O3T contents and low K2O and TiO2 contents, and are characterized by depletion of HREEs and notably negative Nb-Ta anomalies, with enrichment of Rb, Ba, and U, which indicate an enriched mantle source. The Early Permian granites of the Zhusileng area are highly differentiated I-type granitoids sourced from mixing of mantle and crust, are high-K calc-alkaline and enriched in LREEs, and exhibit moderately to strongly negative Eu anomalies. All the intrusive rocks formed in a post-collisional extensional environment, which indicates that the branch of the PAO in the northern Alxa area had closed before the Early Permian. The Cu-Mo/Au mineralization in the Zhusileng area formed in the Middle to Late Permian and is genetically linked to the Late Paleozoic post-collisional rifting magmatism from after the closure of the Paleo-Asian Ocean. [ABSTRACT FROM AUTHOR]