In situ growth of imine-based covalent organic framework as stationary phase for open-tubular capillary electrochromatographic separation.

Designing advanced stationary phases to improve separation efficiency is essential in capillary electrochromatography. Due to their outstanding performance, covalent organic frameworks have recently demonstrated considerable promise in the field of separation science. Herein, an open-tubular capillary electrochromatography method was reported using porous imine-based covalent organic framework with sufficiently available interaction sites as stationary phase. The imine-based covalent organic framework coated capillary was easily prepared via an in situ growth method at room temperature, and its separation performance was evaluated, indicating the high separation efficiency for three types of analytes, including herbicides, polybrominated dibenzofurans, and bisphenols. Moreover, the imine-based covalent organic framework coated capillary showed good reproducibility and stability, with intraday (n = 3), interday (n = 3), and column-to-column (n = 3) relative standard deviations of retention time and peak areas of less than 5%. The separation efficiency of the coated capillary remained unchanged even after 200 runs and the maximum theoretical plates reached up to 85 595 N/m for 4,4'-ethylidenebisphenol. It was predicted that the imine-based covalent organic framework stationary phase would be a strong contender for chromatographic separation with high efficiency.

Fluorescent/Colorimetric Dual-Mode Discriminating Gln and Val Enantiomers Based on Carbon Dots.

Discrimination and quantification of amino acid (AA) enantiomers are particularly important for diagnosing and treating diseases. Recently, dual-mode probes have gained a lot of research interest because they can catch more detecting information compared with the single-mode probes. Thus, it is of great significance to develop a dual-mode sensor realizing AA enantiomer discrimination conveniently and efficiently. In this work, carbon dot L-TCDs were prepared by N-methyl-1,2-benzenediamine dihydrochloride (OTD) and l-tryptophan. With the assistance of H2O2, L-TCDs show an excellent discrimination performance for enantiomers of glutamine (Gln) and valine (Val) in both fluorescent and colorimetric modes. The fluorescence enantioselectivity of Gln (FD/FL) and Val (FL/FD) is 5.29 and 4.13, respectively, and the colorimetric enantioselectivity of Gln (ID/IL) and Val (IL/ID) is 13.26 and 3.42, individually. The chiral recognition mechanism of L-TCDs was systematically studied. L-TCDs can be etched by H2O2, and the participation of AA enantiomers results in different amounts of the released OTD, which provides fluorescent and colorimetric signals for identifying and quantifying the enantiomers of Gln and Val. This work provides a more convenient and flexible dual-mode sensing strategy for discriminating AA enantiomers, which is expected to be of great value in facile and high-throughput chiral recognition.

Memory performance mediates the relationship between depression and independence in instrumental activities of daily living among community-dwelling older adults: Evidence from the China Family Panel Study.

Our objective was to examine the link between depression and independence in the instrumental activities of daily living (IADLs) and to explore the mediating role of memory performance through a cross-sectional analysis of a nationally representative sample of community-dwelling older adults in China. In total, 3730 respondents age ≥ 60 (51.7% males) from the 2020 survey of the China Family Panel Study (CFPS) constituted the study sample. Their depressive symptoms, memory performance, and independence in the IADLs were measured. Based on the descriptive statistics, bivariate correlation analysis and bootstrapping mediation analysis were conducted. As hypothesized, independence in the IADLs was negatively related to depression, while it was positively associated with memory performance. Moreover, after controlling for demographic factors, memory performance was demonstrated to be a partial mediator between depression and independence in the IADLs. These findings support the development of clinical interventions which prevent disability or maintain the physical functioning of older adults through alleviating depression and enhancing memory performance.

Sensing patches for biomarker identification in skin-derived biofluids.

In conventional clinical disease diagnosis and screening based on biomarker detection, most analysis samples are collected from serum, blood. However, these invasive collection methods require specific instruments, professionals, and may lead to infection risks. Additionally, the diagnosis process suffers from untimely results. The identification of skin-related biomarkers plays an unprecedented role in early disease diagnosis. More importantly, these skin-mediated approaches for collecting biomarker-containing biofluid samples are noninvasive or minimally invasive, which is more preferable for point-of-care testing (POCT). Therefore, skin-based biomarker detection patches have been promoted, owing to their unique advantages, such as simple fabrication, desirable transdermal properties and no requirements for professional medical staff. Currently, the skin biomarkers extracted from sweat, interstitial fluid (ISF) and wound exudate, are achieved with wearable sweat patches, transdermal MN patches, and wound patches, respectively. In this review, we detail these three types of skin patches in biofluids collection and diseases-related biomarkers identification. Patch classification and the corresponding manufacturing as well as detection strategies are also summarized. The remaining challenges in clinical applications and current issues in accurate detection are discussed for further advancement of this technology (Scheme 1).

Association between WeChat Use and Memory Performance among Older Adults in China: The Mediating Role of Depression.

Changes to memory performance in the course of aging may be influenced by behavioral factors. The use of social media among elderly people is increasing, but studying its effect on cognitive functions such as memory remains at an early stage of development. Meanwhile, the linking mechanisms underlying the association between social media use and memory performance, if any exist, have not been revealed. This study attempted to examine the association between the use of WeChat, the most popular social media platform in China, and memory performance among older people, and to test the possible mediating role of depression underlying this association. Data were drawn from the five-wave survey of the China Family Panel Study (CFPS), and 4929 respondents aged 60 or older (mean age = 68.19, SD = 5.84, 48.2% females) were included. Based on the descriptive statistics, the chi-squared test, Student's t-test, correlation analysis, and mediation analysis were conducted. The results indicated that the usage rate of WeChat among the sample was 20.1%. After controlling for demographic variables, the use of WeChat was related to higher levels of memory performance and lower levels of depression. Moreover, depression partially mediated the relationship between WeChat use and memory performance. To maintain memory performance and promote cognitive health in the course of aging, using social media and alleviating depression merit special attention.

Synthesis of a covalent organic framework with hydrazine linkages and its application in open-tubular capillary electrochromatography.

Recently, covalent organic frameworks (COFs), owning to their excellent and unique properties, are attracting the attention of numerous researchers in some areas, especially the domain of chromatographic separation. However, the application of hydrazine linkages COFs in open-tubular capillary electrochromatography (OT-CEC) lies in the early stage at present. Herein, a well-crystallized hydrazine-linked COF (Tf-DHzOH) was synthesized successfully from 2,5-dihydroxyterephtalohydrazide and 1,3,5-triformyl-benzene. Tf-DHzOH was firstly regarded as a stationary phase material to prepare the Tf-DHzOH coated capillaries with different coating thickness by covalent bonding in this work. The characterization results showed that Tf-DHzOH was successfully synthesized. The separation performance and stability of the Tf-DHzOH coated capillary were evaluated by considering amino acids, sulfonamides, tetracyclines and benzene compounds as analytes. The relative standard deviations (RSDs) of separation time in the intra-day (n = 9), inter-day (n = 6), column-to-column (n = 3) and batch-to-batch (n = 3) were 0.76-4.97%, 1.59-5.94%1.78-8.72% and 1.66%-8.23%, respectively, the RSDs of peak areas were 1.90-5.16%, 1.73-5.24%, 1.26-7.33% and 3.77%-11.24%, respectively. It was confirmed that there was no visible change of separation efficiency after the Tf-DHzOH-coated capillary was used more than 200 runs. The results make clear that 2D hydrazine-linked COF (Tf-DHzOH) has superior potential as the stationary phase in OT-CEC for chromatographic separation.

Synthesis of spherical three-dimensional covalent organic frameworks and in-situ preparation of capillaries coated with them for capillary electrochromatographic separation.

Covalent organic frameworks (COFs) are divided into two-dimensional (2D) and three-dimensional (3D) structures according to the connection dimension of covalent bonds. 3D COFs have smaller pore size and larger surface area, which would facilitate the separation of small organic molecules with similar structures and properties in capillary electrochromatographic (CEC) separation. However, the application of 3D COFs in CEC is still in its early stages. Thus, 3D COFs (3D-IL-COF-1 and 3D-IL-COF-2) were synthesis by a new synthesis method in this work. The related characterization results confirmed that spherical 3D-IL-COFs formed by the accumulation of small polyhedral particles were successfully synthesized. Then, 3D-IL-COFs were introduced into the inner wall of capillary by in-situ growth method to prepare the 3D COFs coated capillaries for the first time. The electrochromatographic separation performance of the 3D-IL-COFs coated capillaries was investigated using the 3D-IL-COF-1 coated capillary as the model. The results indicate that the 3D-IL-COF-1 coated capillary with uniform coating exhibits a broad-spectrum separation capacity not only for acidic, basic and neutral analytes but also for neutral isomers, which shows that 3D-IL-COFs becomes an attractive potential stationary phase for electrochromatographic separation.

Preparation of biomass-based hydrogels and their efficient heavy metal removal from aqueous solution.

In this work, a porous tobacco straw-based polyacrylic acid hydrogel STS-PAA with high adsorption performance was prepared by polymerizing pretreated waste tobacco straw (TS) with acrylic acid/potassium acrylate by UV radiation initiation. The adsorption performance of metal ions was investigated. The effects of different temperatures (25°C, 35°C, and 45°C), adsorption times (1-420 min), pH values (2.0-6.0) and initial concentrations (0.25-4.0 mmol L-1) of metal ions on the adsorption amount of heavy metal ions were investigated. The results showed that the hydrogel had a high removal rate of Pb2+, Cd2+ and Hg2+ in aqueous solution. The adsorption of Pb2+ was particularly effective. When C0 = 4.0 mmol L-1, pH = 6, the equilibrium adsorption amount of Pb2+, Cd2+ and Hg2+ reached 1.49 mmol g-1, 1.02 mmol L-1 and 0.94 mmol g-1, respectively. The chemical structure and morphology of the hydrogels were characterized by FT-IR, EDS, SEM and XPS. The Langmuir model fits well with the adsorption system. The kinetic data suggest the adsorption of Pb2+, Cd2+ and Hg2+ follow the pseudo-first-order model. This indicates that STS-PAA adsorption of three heavy metal ions is monolayer physical adsorption. Thermodynamic analysis shows that the adsorption of Pb2+, Cd2+ and Hg2+ by STS-PAA is an endothermic (ΔH>0) entropy increase (ΔS>0) non-spontaneous reaction.

Study of the separation ability differences of three covalent organic frameworks as coated materials in capillary electrochromatography.

Covalent organic frameworks (COFs) have great potential applications in chromatographic separation. So it is crucial to understand the relationship between the separation ability of COFs and their structures. Here we report a strategy to evaluate the separation ability of three 2D COFs and explore the relationship between separation ability and their molecular structures. The three 2D COFs (COF-LZU1, COF-42 and COF-LZU8) have one same building unit 1,3,5-triformylbenzene, while varied from the conjugated linking units and functional side-chains. They were used to construct coated capillary column for capillary electrochromatographic separation of same groups of phthalates. They exhibited different separation efficiencies. COF-42 and COF-LZU8 coated capillary columns provided good signal resolutions and high column efficiencies with high theoretical plate numbers. It is demonstrated that COFs with hydrazone unit and longer side-chains provided higher selectivity and resolutions for the phthalates separation. Molecular simulations and DFT calculations were further proceeded to explore the deep reason why the three COFs coated CEC displayed different separation ability based on the host-guest interactions on molecular level. This work highlights a new opportunity to select or design functional COFs and improve their efficiency in chromatographic separation based on host-guest chemistry.

Rapid qualitative and quantitative analysis of trace aconitum phytotoxin by SERS.

The dual functions of phytotoxin, such as aconitine, with biological activity and toxicity ignited the related food poisoning intentionally or accidentally from time to time. The fast and accurate qualitative analysis is a prerequisite for tracking the source of poisoning and taking correct treatments. Taking the single molecule level sensitivity and molecular fingerprinting of Surface-enhanced Raman spectroscopy (SERS), we developed a highly sensitive and accurate strategy for the trace detection of three structurally similar aconitines (ATs) (aconitine, mesaconitine and hypoaconitine) by employing the 100 nm Ag NPs colloid as the SERS substrate. It was figured out that the lowest detectable concentration is in the level of 5.0 µg/L for these three ATs with the linear range of 5.0-100.0 µg/L. The qualitative and quantitative analysis of trace ATs spiked in various food samples was realized in 3 mins, which demonstrated the SERS based strategy is very promising towards the fast and on-site detection of ATs in the field of food safety or criminal identification.

Adaptive harmony search algorithm utilizing differential evolution and opposition-based learning.

An adaptive harmony search algorithm utilizing differential evolution and opposition-based learning (AHS-DE-OBL) is proposed to overcome the drawbacks of the harmony search (HS) algorithm, such as its low fine-tuning ability, slow convergence speed, and easily falling into a local optimum. In AHS-DE-OBL, three main innovative strategies are adopted. First, inspired by the differential evolution algorithm, the differential harmonies in the population are used to randomly perturb individuals to improve the fine-tuning ability. Then, the search domain is adaptively adjusted to accelerate the algorithm convergence. Finally, an opposition-based learning strategy is introduced to prevent the algorithm from falling into a local optimum. The experimental results show that the proposed algorithm has a better global search ability and faster convergence speed than other selected improved harmony search algorithms and selected metaheuristic approaches.

A novel fast-dried urine spot-based method for the analysis of EtS and EtG in urine by liquid chromatography tandem mass spectrometry.

Ethyl sulfate (EtS) and ethyl glucuronide (EtG) in urine are biomarkers to monitor ethanol consumption. Due to their high polarity, severe matrix effects have been observed during analysis of EtS and EtG in urine by liquid chromatography tandem mass spectrometry (LC-MS/MS), which can lead to a loss of sensitivity and accuracy. In the present study, a novel and simple sample preparation approach based on fast-dried urine spot was established to reduce the matrix effect of EtS and EtG in urine. 20 µL of urine was dropped on the Whatman 903# paper and was subsequently dried by microwave in one minute. After ultrasonic assisted extraction with 500 µL of methanol, the analysis was conducted using an LC-MS/MS system. Limits of detection were 5 ng/mL and linear ranges were 10 ng/mL-10 µg/mL for both EtS and EtG. Matrix effects were in the range of 99.3-107.8% for EtS and 86.7-91.0% for EtG at three QC levels. Matrix effects for EtS and EtG were compared between the current method and other sample preparation methods including protein precipitation, and solid-phase extraction. The results showed that this fast-dried urine spot-based extraction method could eliminate matrix effects significantly in analysis of urine EtS and EtG by LC-MS/MS.

Isatin inhibits the invasion and metastasis of SH­SY5Y neuroblastoma cells in vitro and in vivo.

Indoline­2,3­dione or indole­1H­2,3­dione, commonly known as isatin, is found in plants of genus Isatin and in Couropita guianancis aubl, and inhibits tumor cell proliferation through its antioxidant effects. The present study analyzed the effect of isatin on the malignant phenotype of neuroblastoma cells, and reported that isatin significantly inhibited neuroblastoma cell proliferation, invasion and migration in vitro in a dose­dependent manner, and distant metastasis in tumor­bearing mice. Mechanistically, isatin inhibited lysine­specific histone demethylase (LSD)1 and reversed the blockade on p53, thereby activating the apoptotic pathway. The inhibitory effect of isatin on LSD1 may be mediated via direct binding and molecular docking or indirectly through the TGFß/ERK/NF­κB signaling pathway. Isatin also alleviated the renal and hepatic toxicity of cyclophosphamide in the tumor­bearing mice, indicating its potential as a candidate drug as well as an adjuvant for treating metastatic neuroblastoma.

High and fast adsorption of Cd(II) and Pb(II) ions from aqueous solutions by a waste biomass based hydrogel.

A waste biomass based hydrogel soybean residue-poly(acrylic acid) (SR-PAA) was prepared through a fast one-step reaction by UV radiation technology. SR-PAA was used to remove Cd(II) and Pb(II) ions from aqueous solutions. Effect of pH value, temperature, initial concentration, contact time, competitive ions in the solutions on metal ions adsorption and desorption/regeneration capacity of SR-PAA was discussed in detailed. It was found that the adsorption equilibrium was achieved within 20 min, and maximum adsorption for Cd(II) and Pb(II) ions were 1.43 and 2.04 mmol g-1, respectively. Besides, adsorption thermodynamic analysis indicates that the process of Cd(II) and Pb(II) ions adsorption was spontaneous, feasible and exothermic in nature. And experimental data fitted the pseudo-second-order and Freundlich isotherm model well. Moreover, XPS spectra analysis proves that the metal ions were adsorbed on SR-PAA due to the interaction of carboxyl, hydroxyl and amine with these ions as ionic bond, coordination bond and electrostatic interaction.

Isatin inhibits SH-SY5Y neuroblastoma cell invasion and metastasis through PTEN signaling.

OBJECTIVE: Isatin has gained attention in recent years owing to its anticancer properties and is thought to offer medical benefits. Isatin is an endogenous oxidized indole with various behavioral and metabolic properties and is commonly found in mammalian tissues and fluids. It has several plausible applications in biomedical research and has also been investigated as a potential anticancer agent. However, its effects on neuroblastoma (NB) cells are unclear. Here, we evaluate the effects of isatin on neuroblastoma cell metastasis and invasion and reveal the underlying mechanism. METHODS: NB cell viability was evaluated with the cell counting kit (CCK)-8 assay. NB cell invasion and migration abilities were tested with transwell and wound healing experiments. The relative mRNA expression of associated molecules was detected with real-time polymerase chain reaction (RT-PCR) and quantitative PCR. The expression level of related proteins was detected with western blotting. RESULTS: Isatin inhibited the proliferation, invasion, and migration of neuroblastoma cells in a dose-dependent manner. Isatin increased the expression level of H3K4m1 and phosphatase and tensin homolog (PTEN) and decreased the phosphorylation level of PTEN downstream proteins phosphoinositide 3-kinase, protein kinase B, mammalian target of rapamycin, focal adhesion kinase, and SHC. Together, these results support the potential anti-metastatic effects of isatin on NB cells.