Single-cell sequencing of the substantia nigra reveals microglial activation in a model of MPTP.

Background: N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is a neurotoxin widely used to induce PD models, but the effect of MPTP on the cells and genes of PD has not been fully elucidated. Methods: Single-nucleus RNA sequencing was performed in the Substantia Nigra (SN) of MPTP mice. UMAP analysis was used for the dimensionality reduction visualization of the SN in the MPTP mice. Known marker genes highly expressed genes in each cluster were used to annotate most clusters. Specific Differentially Expressed Genes (DEGs) and PD risk genes analysis were used to find MPTP-associated cells. GO, KEGG, PPI network, GSEA and CellChat analysis were used to reveal cell type-specific functional alterations and disruption of cell-cell communication networks. Subset reconstruction and pseudotime analysis were used to reveal the activation status of the cells, and to find the transcription factors with trajectory characterized. Results: Initially, we observed specific DEGs and PD risk genes enrichment in microglia. Next, We obtained the functional phenotype changes in microglia and found that IGF, AGRN and PTN pathways were reduced in MPTP mice. Finally, we analyzed the activation state of microglia and revealed a pro-inflammatory trajectory characterized by transcription factors Nfe2l2 and Runx1. Conclusion: Our work revealed alterations in microglia function, signaling pathways and key genes in the SN of MPTP mice.

Zoledronic Acid Accelerates Bone Healing in Carpal Navicular Fracture via Silencing Long Non-coding RNA Growth Arrest Specificity 5 to Modulate MicroRNA-29a-3p Expression.

Carpal navicular fractures are the most common carpal fractures. This study intends to explore the specific mechanism of Zoledronic Acid (ZA) in carpal navicular fracture healing via long non-coding RNA (lncRNA) growth arrest specificity 5 (GAS5) to mediate microRNA (miR)-29a-3p. A fractured rat model was constructed. Two weeks later, a subcutaneous injection of systemic ZA was implemented, and an injection of plasmid vectors interfered with GAS5 or miR-29a-3p expression was performed on the fracture site. Osteocalcin (OCN) and bone morphogenetic protein-2 (BMP-2) were determined, as well as serum levels of alkaline phosphatase (ALP), osteopontin (OPN) and osteoprotegerin (OPG) and bone mineral density. MC3T3-E1 cells were transfected with plasmid vectors interfering with GAS5 or miR-29a-3p, and cell proliferation and apoptosis were analyzed. GAS5 and miR-29a-3p expression in fractured rats was tested, together with their binding relationship. ZA promoted OCN and BMP-2 expression, increased bone mineral density and serum levels of ALP, OPN and OPG in fractured rats. GAS5 was upregulated and miR-29a-3p was down-regulated in fractured rats. Downregulation of GAS5 or upregulation of miR-29a-3p further promoted bone healing in fractured rats. GAS5 targets miR-29a-3p, and down-regulation of miR-29a-3p can reverse the effect of down-regulation of GAS5 on bone healing in fractured rats. ZA promoted the proliferation of MC3T3-E1 cells and inhibited apoptosis by regulating the GAS5/miR-29a-3p axis. ZA regulates miR-29a-3p expression by down-regulating GAS5 to promote carpal navicular fracture healing, promote MC3T3-E1 cell proliferation, and inhibit cell apoptosis.

Bimetallic metal-organic frameworks-based ratiometric fluorescence sensor for the quantitative detection of thiram in fruits samples.

The identification of residual thiram (Tr) in foods is vital in view of its harmful effects on human health. Herein, a ratiometric fluorescence sensor (I435/I590) based on rhodamine B/NH2-MIL-53(Al0.75Fe0.25) was constructed for the detection of Tr. Interestingly, the probe RhB/NH2-MIL-53(Bim) assisted by Cu2+ could rapidly and sensitively recognize Tr with a low detection limit of 0.11 µg/mL in 10 min. The fluorescence sensing mechanism was investigated using fluorescence spectra, UV-Vis absorption spectra, the fluorescence lifetime and quantum yield. The results showed that the excellent sensing performance was attributed to fluorescence resonance energy transfer, electrostatic interaction, and photoinduced electron transfer. In addition, the practical application of this platform showed acceptable relative recoveries for Tr (84.03-107.81 %), and precisions were also achieved (relative standard deviation ≤ 8.69 %, n = 3). These results show that the presented herein can be applied to monitor the Tr content in real fruit samples.

An ultralow concentration of Al-MOFs for turn-on fluorescence detection of aflatoxin B1 in tea samples.

A turn-on fluorescent sensing platform based on an ultralow concentration of Al-metal organic frameworks for the detection of aflatoxin B1 has been developed for the first time. This fluorescence turn-on sensor exhibits the largest fluorescence enhancement (or quenching) constant value of 179404 M-1 among all luminescence-based chemical sensors reported till date. Moreover, the sensor afforded a rapid detection of aflatoxin B1, with a linear response in the concentration range of 0.05-9.61 µM and a low detection limit of 11.67 ppb. Additionally, the fabricated sensor showed good repeatability, reproducibility, stability, and selectivity. Most importantly, the practical application of this sensor has been demonstrated by detecting aflatoxin B1 in complex tea samples with low relative standard deviation (≤7.72%; n = 3) and satisfactory recoveries. In summary, the proposed method has great potential as a simple, sensitive and selective strategy for monitoring aflatoxin B1 in food samples.

Draxin inhibits chick trunk neural crest delamination and migration by increasing cell adhesion.

The neural crest is a multipotent cell population that migrates extensively to play important roles during embryonic development. After acquiring motility, trunk neural crest cells delaminate from the spinal cord and migrate to various regions of the body. Several cellular adhesion molecules, such as vinculin, are involved in the regulation of neural crest delamination and migration. In the present study, we found that draxin could inhibit delamination and migration of neural crest cells from the chick spinal cord and abnormal aggregation of the migrating neural crest cells. In the presence of draxin, the resuspended neural crest regained its adhesive ability such that it was significantly increased. Overexpression of draxin caused increased vinculin expression in vivo. Our data indicate that draxin might control delamination and migration of chick trunk neural crest by increasing cell adhesion.

Use of 1-octyl-3-methylimidazole hexafluorophosphate modified magnetic hyperbranched polyamideamine as sorbent for the extraction of pyrethroid insecticides from tea infusion.

Magnetic hyperbranched polyamideamine was carboxylated using succinic anhydride and modified further with 1-octyl-3-methylimidazole hexafluorophosphate successively. The morphology and chemical composition of the prepared material was characterized by transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller measurement, X-ray photoelectron spectroscopy, etc. 1-Octyl-3-methylimidazole hexafluorophosphate modified magnetic hyperbranched polyamideamine was used as sorbent in the magnetic solid-phase extraction for the separation and enrichment of five pyrethroid insecticides from tea infusion. The magnetic solid-phase extraction method proposed in this article has low method detection limits (0.53-0.71 ng/mL), acceptable coefficient of determination (0.9992-0.9998), wide linear ranges (2.5-500.0 ng/mL), and good repeatability (intraday: 1.2-6.3%; interday: 1.6-5.4%). In the detection of five pyrethroid insecticides in tea infusion, relative recoveries were in the range from 87.7 to 114.7% with satisfactory relative standard deviations (0.2-7.4%). With the aid of quantum chemistry calculations, the interaction energy between the sorbent and five pyrethroid insecticides was calculated, which proved the necessity of the modification of 1-octyl-3-methylimidazole hexafluorophosphate.

Hyperbranched aromatic polyamide modified magnetic nanoparticles for the extraction of benzoylurea insecticides.

Herein, a novel hyperbranched aromatic polyamide-coated magnetic sorbent was prepared by in situ polymerization on the surface of amino-functionalized Fe3 O4 nanoparticles. The magnetic sorbent was characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, elemental analysis, Brunauer-Emmett-Teller measurement, and X-ray photoelectron spectroscopy, etc. The new magnetic sorbent was used in the magnetic solid-phase extraction for the detection of seven benzoylurea insecticides. Under optimum conditions, low method detection limits (0.56-1.20 ng/mL), acceptable coefficient of determination (0.9967-0.9996), wide linear ranges (2.5-500.0 ng/mL), and good repeatability (intraday: 2.0-7.3%; interday: 1.9-9.2%) were achieved. The magnetic solid-phase extraction method based on the new magnetic sorbent showed good reliability in the analysis of seven benzoylurea insecticides in real water samples, as the relative recoveries were in the range from 80.1 to 116.3% with satisfactory RSDs (0.1-9.8%). By means of density functional theory and semiempirical quantum mechanical, the binding configuration and interaction energy of hyperbranched aromatic polyamide and benzoylurea insecticides were calculated. The result of theoretical calculation revealed that the adsorption of benzoylurea insecticides by hyperbranched aromatic polyamide was derived from hydrogen bonding and π-π stacking. The contribution of π-π stacking was greater than that of hydrogen bond, which was confirmed by energy decomposition analysis.

Preparation of magnetic attapulgite/polypyrrole nanocomposites for magnetic effervescence-assisted dispersive solid-phase extraction of pyrethroids from honey samples.

In this work, a novel extraction technique based on the effervescence-assisted dispersion and magnetic recovery of attapulgite/polypyrrole sorbents was developed for determining the concentrations of five pyrethroids in honey samples. The magnetic nanoparticles were synthesized by a one-pot method. Several experimental parameters that affected the extraction efficiency, including the dispersion conditions, pH, ionic strength, and desorption conditions, were investigated. Under optimal conditions, the calibration curves for the five pyrethroids in honey samples exhibited good linearity, with r2 values ranging from 0.9979 to 0.9990. The limits of detection varied between 0.21 and 0.34 µg/L. Satisfactory recoveries of 81.42-106.73% with intra- and interday relative standard deviations of less than 6.94 and 10.89%, respectively, were obtained. Moreover, the sorbents exhibited acceptable batch-to-batch repeatability in the range of 5.06-15.01%, and each sorbent could be reused for up to four extraction cycles without a significant loss in the extraction recovery.

Attapulgite modified magnetic metal-organic frameworks for magnetic solid phase extraction and determinations of benzoylurea insecticides in tea infusions.

Herein, we developed a novel magnetic solid phase extraction method based on attapulgite-modified magnetic metal-organic frameworks (ATP@Fe3O4@ZIF-8), and this method could be used for the determination of benzoylureas when it was coupled with high-performance liquid chromatography. The established method was validated in terms of linearity (2.5-500 µg L-1, with correlation coefficient (R2) > 0.9994), accuracy (with satisfactory recovery of 88.29-95.99%) and precision (with relative standard deviation (RSD) of less than 8%). In addition, the enrichment factors (EF) ranged from 63.6 to 72.2. Limit of detection (LOD) and limit of quantitation (LOQ) were 0.7-3.2 µg L-1 and 2.3-10.7 µg L-1, respectively. Moreover, there was hardly any noticeable loss of the extraction efficiency when this extraction method undergoes five cycles. Finally, this method was successfully used for the determination of six benzoylureas in different tea infusions and the determined relative recoveries ranged from 78.8 to 114.3%.

PEG-modified magnetic Schiff base network-1 materials for the magnetic solid phase extraction of benzoylurea pesticides from environmental water samples.

It is necessary to establish a rapid, simple and environmentally friendly detection method for benzoylurea pesticides (BUs) in environmental water samples because of their toxicity in environmental circulation. Herein, a novel polyethylene glycol (PEG) modified magnetic covalent organic framework material based on the Schiff base reaction was prepared (PEG/Fe3O4@SNW-1). This material was used as a sorbent for enriching five BUs by magnetic solid phase extraction prior to detection via high-performance liquid chromatography. After the optimization of several parameters (such as the salinity, extraction time, amount of sorbent, desorption time, etc.) that influenced the recovery of the magnetic solid phase extraction process, the limits of detection (S/N = 3) were defined as less than 1.0 µg L-1, and the limits of quantitation (S/N = 10) were calculated as being lower than 3.4 µg L-1. A satisfactory linear range of 5-1000 µg L-1 was achieved. Finally, the proposed method was applied to analyze benzoylurea pesticides in three environmental water samples. These results indicated that the proposed method was feasible and demonstrated the potential application of the PEG/Fe3O4@SNW-1 material for detecting similar pesticide residues in environmental water samples.

Extraction of benzoylurea pesticides from tea and fruit juices using deep eutectic solvents.

In this study, low-density deep eutectic solvent combined with dispersive liquid-liquid microextraction was applied to the extraction of five benzoylurea insecticides (BUs, including diflubenzuron, triflumuron, hexaflumuron, flufenoxuron, and chlorfluazuron) from beverages. Then the extracted and concentrated samples were analyzed and detected using the high-performance liquid chromatography combined with an ultraviolet detector. The DESs were synthesized by [P14,6,6,6]Cl as hydrogen bond acceptor and tetradecyl alcohol as hydrogen bond donor, and then characterized by Fourier transform infrared spectroscopy. In the experiment, the key factors affecting the extraction efficiency were screened by Plackett-Burman design and optimized with the central composite design. The extraction recovery rates were 85.91-95.12%. The limits of detection and correlation coefficients of the method were 0.30-0.60 µg L-1 and 0.9992-0.9997. Finally, the method was applied to determine the BUs in four beverage samples, and satisfactory recoveries, within the range of 76.87-101.19% were achieved. The present method has the potential to be applied to the detection of BUs in aqueous samples.

Methyl chloride produced during UV254 irradiation of saline water.

Ultraviolet (UV) irradiation is widely used for water treatment due to its effectiveness against a wide range of waterborne pathogens with minimal production of regulated disinfection byproducts. However, in this study, the formation of methyl chloride (CH3Cl) from guaiacol and chloride was observed during UV254 irradiation. The results indicated that direct photolysis of guaiacol produced an arenium ion, and the reactive methoxy group was further transformed to CH3Cl in the presence of chloride. O-quinone was detected as the primary product of the degradation of guaiacol resulting from UV254 irradiation. Other organic compounds containing methoxy, ethoxy, or methylamino groups with structures that are similar to guaiacol were also demonstrated to generate halocarbons in aqueous chloride or bromide solution under UV254 irradiation. Scavenging experiments and removal of oxygen demonstrated that neither oxygen nor chlorine radicals were involved in CH3Cl formation. In seawater samples, CH3Cl was also detected in the presence or absence of added organic matter. These results demonstrate that CH3Cl can be formed during UV254 irradiation in saline water and that attention should be paid to this compound and structurally-related compounds in the application of UV254 processes.

Humic acid functionalized hyperbranched polytriazine based dispersive solid-phase extraction for acaricides determination in tea matrix.

Hyperbranched polytriazine functionalized with humic acid was prepared and developed as new sorbents for dispersive solid-phase extraction of three acaricides (clofentezine, fenpyroximate, and pyridaben) in tea samples combined with high-performance liquid chromatography detection. The sorbents were characterized by scanning electron microscopy, energy dispersive spectroscopy, Zeta-potential, and Fourier transform infrared spectroscopy. The extraction parameters (extraction time, ionic strength, desorption conditions) were optimized. The adsorption mechanism was evaluated utilizing Fourier transform infrared spectra. Under optimum conditions, satisfactory analytical performances were achieved, which included high precision (1.33-9.62%), low limits of detection (0.19-3.54 µg/L), and wide linear range (2.5-500 µg/L) for the analysis of the acaricides. Moreover, the proposed method proved highly effective for the determination of acaricides in tea samples, with the relative recoveries in the range of 65.20-108.13% and relative standard deviations < 9.87%. The method has great application potential for the detection of acaricides in tea samples.

Magnetic nanoparticles modified with hyperbranched polyamidoamine for the extraction of benzoylurea insecticides prior to their quantitation by HPLC.

A magnetic sorbent was fabricated by covalently grafting hyperbranched polyamidoamine onto the surface of Fe3O4 nanoparticles. The sorbent was used in the magnetic solid-phase extraction (MSPE) of benzoylurea insecticides (BUs) from environmental water samples. It is perceived that hydrogen bonding interactions and hydrophobic interactions are the main mechanisms for the adsorption of BUs. The sorbent was characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, elemental analysis, Brunauer-Emmett-Teller measurement, X-ray photoelectron spectroscopy, vibrating sample magnetometry and X-ray diffraction. Various experimental parameters affecting the MSPE were optimized. Following elution with acetonitrile, the BUs were quantified by HPLC with diode array detection. The method based has a wide linear response range (2.5-500.0 ng mL-1), satisfactory coefficient of determination (0.9922-0.9976), high enrichment factors (62.8-74.4), acceptable limits of quantitation (2.5 ng mL-1) and low limits of detection (0.39-0.72 ng mL-1). The intra-day precision at concentration levels of 5.0, 50.0 and 250.0 ng mL-1 ranged from 2.3-6.4% and the inter-day precision was between 1.0 and 5.5%. The sorbent can be re-used at least 15 times. It was applied to the extraction of BUs from genuine water samples where it showed satisfactory relative recoveries (75.1-111.4%) and precision (1.0-9.1%). Graphical abstract Schematic presentation of magnetic nanoparticles modified with hyperbranched polyamidoamine and their application for extraction of benzoylurea insecticides.

Vortex-assisted deep eutectic solvent reversed-phase liquid-liquid microextraction of triazine herbicides in edible vegetable oils.

In this study, four triazine herbicides-namely, simazine, ametryn, prometryn and terbuthylazine-were separated and determined using high-performance liquid chromatography coupled with ultraviolet detector (HPLC-UVD). The deep eutectic solvent (DES) formed by tetrabutylammonium chloride ([N4444]Cl, TBA) and ethylene glycol (EG) was selected as the extraction solvent of vortex-assisted reversed-phase liquid-liquid microextraction (VA-RPLLME). The application of the hydrophilic DES expands the range of choice for LLME. The experimental parameters affecting the extraction recoveries, including the amount of the DES, the sample volume and the vortex time, were investigated and optimized by the design of experiments (DoE) methodology. A quadratic model, namely central composite face-centered (CCF) design featuring 20 runs was used instead of the conventional trial and error approach. Under optimum conditions, the limits of determination (LODs) of the method were 0.60-1.50 µg L-1. The enrichment factors for the analytes ranged from 27 to 31. The extraction recoveries were in the range of 84.1-104.9%, and the intra-day, inter-day and intermediate relative standard deviations (RSDs) were less than 8.4%. Finally, the method was applied for the determination of triazine herbicides in vegetable oil samples. The obtained recoveries were in the range of 60.1-107.2% and RSDs were lower than 8.1%. In general, VA-RPLLME can be complementary to the present available methods for the determination of triazine herbicides in vegetable oil samples.

A dispersive magnetic solid phase microextraction based on ionic liquid-coated and cyclodextrin-functionalized magnetic core dendrimer nanocomposites for the determination of pyrethroids in juice samples.

A novel dispersive magnetic solid phase microextraction method based on ionic liquid-coated and cyclodextrin-functionalized magnetic core dendrimer nanocomposites has been developed for the determination of pyrethroids in juice samples. The different generation magnetic core dendrimer nanocomposites were successfully synthesized and the nanocomposites possess both the selective retention of guest dendrimer and cyclodextrin molecules and high adsorption capacities of ionic liquids. The extraction efficiencies of different generation magnetic core dendrimer nanocomposites were compared, and the type of nanocomposite with the highest recovery was obtained. Under the optimized experimental conditions, the method showed good linearity in the range of 3.5-500 µg L-1. The LODs and LOQs were in the ranges of 0.36-1.3 µg L-1 and 1.2-4.3 µg L-1, respectively. The method also showed acceptable accuracies ranging from 98.2% to 99.4%. The proposed method was demonstrated to broaden the potential applications of dendrimer for the detection of pyrethroid residues in various juice samples.

Ionic liquid-type surfactant modified attapulgite as a novel and efficient dispersive solid phase material for fast determination of pyrethroids in tea drinks.

In this study, a novel ionic liquid-type surfactant modified attapulgite named as 1-dodecyl-3-methylimidazolium bromide-attapulgite (C12MIM-ATP) is successfully prepared and applied in dispersive solid phase extraction (dSPE) for the fast determination of pyrethroid residues in tea drinks. The primary factors that influenced the extraction efficiency, including sorbent type, amount of sorbent, extraction time, desorption conditions, pH and ionic strength, are investigated. The optimized results reveal that the extraction and desorption equilibria are rapidly obtained within 1 min. Under the optimized conditions, good linearity (2-500 µg/L) is observed for four pyrethroids in tea drinks with determination coefficients (r2) ranged from 0.9992 to 1.0000. The limits of detection (LODs) are 0.6 µg/L for all pesticides. Acceptable extraction recoveries of target analytes are found from 90.28 to 107.56% with relative standard deviations (RSDs) less than 8.30% in real tea drink samples. The batch-to-bath repeatability is evaluated by recovery test on five independent synthesized C12MIM-ATP sorbents. Satisfactory batch-to-batch repeatability is obtained with the recovery factors varied in 15%. A small matrix effect is observed using C12MIM-ATP as the sorbent for detection pyrethroids in tea drinks.

Rapid analysis of fungicides in tea infusions using ionic liquid immobilized fabric phase sorptive extraction with the assistance of surfactant fungicides analysis using IL-FPSE assisted with surfactant.

A green, simple, inexpensive, and sensitive ionic liquid immobilized fabric phase sorptive extraction method coupled with high performance liquid chromatography was developed for rapid screening and simultaneous determination of four fungicides (azoxystrobin, chlorothalonil, cyprodinil and trifloxystrobin) residues in tea infusions. This IL modified extraction fiber is capable of extracting target analytes directly from complicated tea water matrices with the addition of surfactant. A series of extraction conditions were investigated by one-factor-at-a-time approach and orthogonal test. After a series experiments, the optimum conditions were found to be 10% [HIMIM]NTf2 as coating solution, 2min vortex time, 500µL acetonitrile as dispersive solvent and 2min desorption time. Under the above conditions, the proposed technique was applied to detect fungicides from real tea water samples with satisfactory results.

Dispersive liquid-liquid microextraction based on the solidification of deep eutectic solvent for the determination of benzoylureas in environmental water samples.

We present a novel dispersive liquid-liquid microextraction method based on the solidification of deep eutectic solvent coupled with high-performance liquid chromatography with a variable-wavelength detection for the detection of five benzoylureas in real water samples. In this work, a green solvent consisting of 1-octyl-3-methylimidazolium chloride and 1-dodecanol was used as an extraction solvent, yielding the advantages of material stability, low density, and a suitable freezing point near room temperature. Parameters that significantly affect extraction efficiency were optimized by the one-factor-at-a-time approach. Under optimal conditions, the recoveries of five target compounds were obtained ranging from 87.39 to 98.05% with correlation coefficients ranging from 0.9994 to 0.9997 for pure water. The limits of detection were in the range of 0.09-0.16 µg/L. The enrichment factors were in the range of 171-188. Linearities were achieved in the range of 0.5-500 µg/L. The proposed method was successfully applied to determine benzoylureas in environmental water samples with a satisfactory recovery of approximately 81.38-97.67%.

Deep eutectic solvent-based ultrasound-assisted dispersive liquid-liquid microextraction coupled with high-performance liquid chromatography for the determination of ultraviolet filters in water samples.

In the present study, a simple and rapid sample preparation method designated ultrasound-assisted dispersive liquid-liquid microextraction based on a deep eutectic solvent (DES) followed by high-performance liquid chromatography with ultraviolet (UV) detection (HPLC-UVD) was developed for the extraction and determination of UV filters from water samples. The model analytes were 2,4-dihydroxybenzophenone (BP-1), benzophenone (BP) and 2-hydroxy-4-methoxybenzophenone (BP-3). The hydrophobic DES was prepared by mixing trioctylmethylammonium chloride (TAC) and decanoic acid (DecA). Various influencing factors (selection of the extractant, amount of DES, ultrasound duration, salt addition, sample volume, sample pH, centrifuge rate and duration) on UV filter recovery were systematically investigated. Under optimal conditions, the proposed method provided good recoveries in the range of 90.2-103.5% and relative standard deviations (inter-day and intra-day precision, n=5) below 5.9%. The enrichment factors for the analytes ranged from 67 to 76. The limits of detection varied from 0.15 to 0.30ngmL-1, depending on the analytes. The linearities were between 0.5 and 500ngmL-1 for BP-1 and BP and between 1 and 500ngmL-1 for BP-3, with coefficients of determination greater than 0.99. Finally, the proposed method was applied to the determination of UV filters in swimming pool and river water samples, and acceptable relative recoveries ranging from 82.1 to 106.5% were obtained.