Embracing city life: physical activities and the social integration of the new generation of female migrant workers in urban China

Drawing on empirical data from interviews with young Chinese female rural-urban migrant workers in the Pearl River Delta of China’s Guangdong province, this article explores the ways in which physical activities help to fulfil the ‘urban dream’ of this new generation of female migrant workers and promote their social integration. The article demonstrates that physical activities exert their influence and facilitate the young female migrant workers’ social integration into cities through four dimensions: ‘space’, ‘network’, ‘identity’ and ‘image’. Participating in sport and exercise expands the scale of workers’ living spaces and contributes to building social networks and selfidentification. It also enhances female migrant workers’ individualistic values, as opposed to family-oriented ones. These new values allow them to enjoy recreational life and to change the stereotypical image of rural-urban migrant workers

A new liquid chromatography–fluorescence method for determination of perfluorooctanesulphonyl fluoride upon derivatisation with 1-naphthol

<div><p>Perfluorooctanesulphonyl fluoride (PFOSF), as a main precursor of perfluorooctanesulphonate (PFOS) that is ubiquitous in the environment, has been released to the environment with substantial quantity. Determination of PFOSF presents significant analytical challenges for using liquid chromatography with UV (LC–UV) and fluorescence detection (LC–FLD) due to the lack of chromophore in the molecular structure. In this study, a new method was developed by derivatising PFOSF with 1-naphthol to form 1-naphthylperfluorooctanesulphonate (NPFOS), which allowed rapid qualitative and quantitative analysis using LC–UV and LC–FLD. The derivatising product was confirmed from the analyses by proton nuclear magnetic resonance and quadrupole–time of flight mass spectrometry. The LC–FLD method demonstrated good linearity in the NPFOS concentration range from 20 pg µL⁻¹ to 20 ng µL⁻¹ with a correlation coefficient better than 0.999, with the instrument detection limit of 1.5 pg µL⁻¹.</p></div

Negative Ion Laser Desorption/Ionization Time-of-Flight Mass Spectrometric Analysis of Small Molecules Using Graphitic Carbon Nitride Nanosheet Matrix

Ultrathin graphitic carbon nitride (g-C₃N₄) nanosheets served as a novel matrix for the detection of small molecules by negative ion matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was described for the first time. In comparison with conventional organic matrices and graphene matrix, the use of g-C₃N₄ nanosheet matrix showed free matrix background interference and increased signal intensity in the analysis of amino acids, nucleobases, peptides, bisphenols (BPs), and nitropolycyclic aromatic hydrocarbons (nitro-PAHs). A systematic comparison of g-C₃N₄ nanosheets with positive and negative ion modes revealed that mass spectra produced by g-C₃N₄ nanosheets in negative ion mode were featured by singly deprotonated ion without matrix interference, which was rather different from the complicated alkali metal complexes in positive ion mode. Good salt tolerance and reproducibility allowed the determination of 1-nitropyrene (1-NP) in sewage, and its corresponding detection limit was lowered to 1 pmol. In addition, the ionization mechanism of the g-C₃N₄ nanosheets as matrix was also discussed. The work expands its application scope of g-C₃N₄ nanosheets and provides an alternative approach for small molecules

Nickel-Catalyzed Regioselective Cleavage of C_sp²–S Bonds: Method for the Synthesis of Tri- and Tetrasubstituted Alkenes

We describe here an efficient route for the synthesis of (<i>Z</i>)-vinylic sulfides <b>3</b> via the highly regio- and stereoselective coupling of (<i>Z</i>)-1,2-bis­(aryl­(alkyl)­thio)­alkenes and Grignard reagents over a Ni catalyst under mild conditions. (<i>Z</i>)-Vinylic sulfides <b>3</b> are important intermediates in the synthesis of tri- and tetrasubstituted alkenes that are important construction blocks for drugs and natural products. The directing organosulfur groups (SR) can be converted to diaryl­(alkyl) disulfides (RSSR) using H₂O₂ as oxidant, hence avoiding the waste of sulfur resources. The protocol provides a general method that is highly regio- and stereoselective for the synthesis of a diversity of tri- and tetrasubstituted alkenes

Cetyltrimethylammonium Bromide-Coated Fe₃O₄ Magnetic Nanoparticles for Analysis of 15 Trace Polycyclic Aromatic Hydrocarbons in Aquatic Environments by Ultraperformance, Liquid Chromatography With Fluorescence Detection

Accurate determination of polycyclic aromatic hydrocarbons (PAHs) in surface waters is necessary for protection of the environment from adverse effects that can occur at concentrations which require preconcentration to be detected. In this study, an effective solid phase extraction (SPE) method based on cetyltrimethylammonium bromide (CTAB)-coated Fe₃O₄ magnetic nanoparticles (MNPs) was developed for extraction of trace quantities of PAHs from natural waters. An enrichment factor of 800 was achieved within 5 min by use of 100 mg of Fe₃O₄ MNPs and 50 mg of CTAB. Compared with conventional liquid–liquid extraction (LLE), C18 SPE cartridge and some newly developed methods, the SPE to determine bioaccessible fraction was more convenient, efficient, time-saving, and cost-effective. To evaluate the performance of this novel sorbent, five natural samples including rainwater, river waters, wastewater, and tap water spiked with 15 PAHs were analyzed by use of ultraperformance, liquid chromatography (UPLC) with fluorescence detection (FLD). Limits of determination (LOD) of PAHs (log <i>K</i>_ow ≥ 4.46) ranged from 0.4 to 10.3 ng/L, with mean recoveries of 87.95 ± 16.16, 85.92 ± 10.19, 82.89 ± 5.25, 78.90 ± 9.90, and 59.23 ± 3.10% for rainwater, upstream and downstream river water, wastewater, and tap water, respectively. However, the effect of dissolved organic matter (DOM) on recovery of PAHs varied among matrixes. Because of electrostatic adsorption and hydrophobicity, DOM promoted adsorption of Fe₃O₄ MNPs to PAHs from samples of water from the field. This result was different than the effect of DOM under laboratory conditions. Because of competitive adsorption with the site of action on the surface of Fe₃O₄ MNPs for CTAB, recoveries of PAHs were inversely proportional to concentrations of Ca²⁺ and Mg²⁺. This novel sorbent based on nanomaterials was effective at removing PAHs at environmentally relevant concentrations from waters containing relevant concentrations of both naturally occurring organic matter and hardness metals

LC–MS-Based Urinary Metabolite Signatures in Idiopathic Parkinson’s Disease

Increasing evidence has shown that abnormal metabolic phenotypes in body fluids reflect the pathogenesis and pathophysiology of Parkinson’s disease (PD). These body fluids include urine; however, the relationship between, specifically, urinary metabolic phenotypes and PD is not fully understood. In this study, urinary metabolites from a total of 401 clinical urine samples collected from 106 idiopathic PD patients and 104 normal control subjects were profiled by using high-performance liquid chromatography coupled to high-resolution mass spectrometry. Our study revealed significant correlation between clinical phenotype and urinary metabolite profile. Metabolic profiles of idiopathic PD patients differed significantly and consistently from normal controls, with related metabolic pathway variations observed in steroidogenesis, fatty acid beta-oxidation, histidine metabolism, phenylalanine metabolism, tryptophan metabolism, nucleotide metabolism, and tyrosine metabolism. In the fruit fly <i>Drosophila melanogaster</i>, the alteration of the kynurenine pathway in tryptophan metabolism corresponded with pathogenic changes in the alpha-synuclein overexpressed <i>Drosophila</i> model of PD. The results suggest that LC–MS-based urinary metabolomic profiling can reveal the metabolite signatures and related variations in metabolic pathways that characterize PD. Consistent PD-related changes across species may provide the basis for understanding metabolic regulation of PD at the molecular level

Comprehensive Analysis of Acylcarnitine Species in <i>db/db</i> Mouse Using a Novel Method of High-Resolution Parallel Reaction Monitoring Reveals Widespread Metabolic Dysfunction Induced by Diabetes

Acylcarnitines are exerting a variety of biological functions depending on the differences in lengths, saturation levels, and conjugation groups, which to a great extent contribute to the challenges of acylcarnitines quantifications due to various kinds of isomers. Here, we describe a novel method by using high-resolution parallel reaction monitoring (PRM) liquid chromatography-tandem mass spectrometry (LC-MS/MS). Both reversed-phase and normal-phase column were used in order to get accurate, reliable, widespread quantification of acylcarnitines, and without tedious sample preparation procedure. The method provided the most comprehensive acylcarnitine profile with high-resolution MS and MS/MS confirmation to date. A total of 117 acylcarnitines were detected from plasma and urine samples. The application of targeted profiling of acylcarnitines in <i>db/m+</i> control and <i>db/db</i> diabetic mice indicated incomplete amino acid and fatty acid oxidation on diabetic mice. Interestingly, the reduction of medium odd-numbered chain acylcarnitines in urine samples was first observed between <i>db/m+</i> and <i>db/db</i> mice. The high-resolution PRM method makes it possible to monitor the widespread metabolic changes of the acylcarnitines in response to stimuli. Besides, the accurate MS and MS/MS spectra data of the 117 acylcarnitines could be used as mass spectrometric resources for the identification of acylcarnitines