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An analytical method was established for the simultaneous detection of five saccharides in tea by multi-plug filtration cleanup (m-PFC) combined with high performance liquid chromatography-evaporative light scattering detector (HPLC-ELSD). An m-PFC cartridge with polyamide powder as sorbent was developed for sample pretreatment. Tea samples were extracted with water while shaking, and then back-extracted with dichloromethane for the removal of impurities. The upper phase was purified using the m-PFC column and detected by HPLC. Quantification was performed by the external standard method. The results showed that the logarithm of the peak areas was linearly related to the logarithm of the concentrations of rhamnose, fructose, glucose, sucrose, and maltose within the linear ranges tested, with correlation coefficients higher than 0.99. The limits of detection (LOD) were in the range of 0.04–0.1 g/100 g, and the limits of quantitation (LOQ) were 0.10–0.20 g/100 g. The average recoveries at three spiked levels were in the range of 91.0%–103%, with relative standard deviations (RSDs) of 1.0%–4.6%. This method has the advantages of simple operation and good purification effect, and is suitable for the quantitation of these five saccharides in tea.

In this study, the transfer rates of nine pesticides with different water solubility (imidaclothiz, acetamiprid, thiamethoxam, imidacloprid, clothianidin, carbendazim, pyraclostrobin, phoxim and etoxazole) from dry tea to infusion were carefully determined using the liquid-chromatography-tandem mass spectrometry (LC-MS/MS). The obtained results show that the transfer of each pesticide from tea spiked with the pesticides to the infusion ranged from 4.54% (etoxazole) to 58.0% (acetamiprid) under the traditional brewing condition in China, which indicates that transfer of pesticides was dependent on their water solubilities. Increases in infusion time resulted in increased transfer within 30 min. However, there was little influence of infusion time on transfer rates after 30 min. When the infusion temperature was between 50 and 100°C, the transfer rates of acetamiprid, thiamethoxam, imidacloprid, carbendazim, pyraclostrobin, phoxim and etoxazole increased with temperature, while transfer rates for imidaclothiz and clothianidin decreased with increasing temperature. After three infusions, the transfer rates of imidaclothiz, thiamethoxam, acetamiprid, and clothianidin were >70%. Our results provide a basis for the rational use of pesticides in tea gardens and a reasonable evaluation of dietary exposure levels of pesticide residues in brewed tea. [ABSTRACT FROM AUTHOR]

Hydrological models play an important role in water resources management and extreme events forecasting, and they are sensitive to the underlying conditions. This study aims to evaluate the impact of different soil-type maps and land-use maps on hydrological simulations and watershed responses by applying the WRF-Hydro (Weather Research and Forecasting Model Hydrological modeling system) distributed hydrological model to the Xijiang River basin. WRF-Hydro runs for four different scenarios for the period 1992–2013. FAO (Food and Agriculture Organization) and GSDE (Global Soil Dataset for Earth System Science) soil-type maps, and MODIS (Moderate-Resolution Imaging Spectroradiometer) and CNLUCC (China Land Use Land Cover Remote Sensing Monitoring Dataset) land-use maps are used in this study. These soil-type maps and land-use maps are freely combined to form four scenarios. It is found that soil moisture and surface runoff are sensitive to soil-type maps, and absorbed shortwave radiation is found to be the least sensitive to soil-type maps. Absorbed shortwave radiation and heat flux are sensitive to land-use maps. The model performance of simulating soil moisture has increased when the soil-type map changes from FAO to GSDE and the land-use map changes from MODIS to CNLUCC for most stations. When the soil-type map changes from FAO to GSDE and the land-use map changes from MODIS to CNLUCC, the biases of simulating streamflow decrease. This study shows that the performance of the offline WRF-Hydro is significantly influenced by soil-type and land-use maps, and better simulation results can be obtained with more realistic underlying surface maps. Significance Statement: The purpose of this study is to evaluate the impacts of land-use and soil-type maps on hydrological processes at the watershed scale by applying a distributed hydrological model WRF-Hydro model for the Xijiang River basin and reveal the importance of choosing land-use and soil-type maps. In this study, two soil-type maps and two land-use maps are used. It is found that soil moisture and surface runoff are sensitive to soil-type maps, and absorbed shortwave radiation and heat flux are sensitive to land-use maps. When using GSDE soil-type and CNLUCC land-use maps, the performance of the model is improved. The underlying conditions should be considered when applying the models in practice. [ABSTRACT FROM AUTHOR]

Secreted proteins are critical mediators in various biological systems, including the immune system, nervous system, and tumor microenvironment. Understanding profound cellular functional heterogeneity in secretion requires multiplexed secreted protein analysis at the single‐cell level. However, most single‐cell protein secretion analysis technologies rely on bulky, expensive instruments, preventing widespread use. Herein, we proposed using a portable and low‐cost desktop scanner to detect multiplexed proteins secreted from single cells. Gold nanoparticle‐enhanced silver staining and tyramide signal amplification are combined to construct a two‐step amplification for single‐cell secretion assay detection. We used this approach to investigate the heterogeneous immune response of macrophages at the single‐cell level, which revealed that only a minority of cells could secrete 10‐fold more MCP‐1 and TNF‐α than the averaged secretion. The reported platform eliminates bulky equipment for single‐cell secretion analysis, making it affordable for basic and clinical research. [ABSTRACT FROM AUTHOR]

Endoplasmic reticulum stress (ERS) and autophagy activation play important roles in the process of cerebral ischemia/reperfusion (I/R) injury. The synergistic protective effects of Geniposide and ursodeoxycholic acid against cellular apoptosis caused by oxygen-glucose deprivation-reoxygenation (OGD/R) were investigated using a Cell Counting Kit-8 assay, lactate dehydrogenase (LDH) assay, flow cytometry, quantitative polymerase chain reaction (qPCR), and western blotting to examine cellular viability, apoptosis, reactive oxygen species (ROS) levels, mRNA and protein levels, respectively, in relation to ERS and autophagy. We found that pretreatment with Geniposide improved cellular viability. Moreover, treatment with a combination of Geniposide and Tauroursodeoxycholic acid (TUDCA) (GT) protected injured cells better than Geniposide alone. Further studies showed that the increase in cellular ROS levels, and the overexpression of mRNA and proteins related to OGD/R-induced ERS and autophagy, were both counteracted by GT. Our study indicates that the protective effects of GT on OGD/R-induced apoptosis in SH-SY5Y cells are associated with the inhibition of ERS and autophagy. [ABSTRACT FROM AUTHOR]

Abstract The quick, easy, cheap, effective, rugged, and safe (QuEChERS) approach is widely used in sample pretreatment in agricultural products, food, environment, etc. And nano-materials are widely used in QuEChERS method due to its small size and large specific surface area. In this review, we examine the typical applications of several commonly used nano-materials in improved QuEChERS method. These materials include multi-walled carbon nanotubes (MWCNTs) and their derivatives, magnetic nanoparticles (MNPs), metal organic frameworks (MOFs), covalent organic frameworks (COFs), graphene oxide (GO), lipid and protein adsorbent (LPAS), cucurbituril (CBs), and carbon nano-cages (CNCs), and so on. The strengths and weaknesses of each nano-material are presented, as well as the challenging aspects that need to be addressed in future research. By comparing the applications and the current technology development, this review suggests utilizing artificial intelligence (AI) to screen suitable combinations of purification agents and performing virtual simulation experiments to verify the reliability of this methodology. By doing so, we aim to accelerate the development of new products and decrease the cost of innovation. It also recommends designing smarter pretreatment instruments to enhance the convenience and automation of the sample pretreatment process and reduce the margin for human error. [ABSTRACT FROM AUTHOR]

The quick, easy, cheap, effective, rugged, and safe (QuEChERS) approach is widely used in sample pretreatment in agricultural products, food, environment, etc. And nano-materials are widely used in QuEChERS method due to its small size and large specific surface area. In this review, we examine the typical applications of several commonly used nano-materials in improved QuEChERS method. These materials include multi-walled carbon nanotubes (MWCNTs) and their derivatives, magnetic nanoparticles (MNPs), metal organic frameworks (MOFs), covalent organic frameworks (COFs), graphene oxide (GO), lipid and protein adsorbent (LPAS), cucurbituril (CBs), and carbon nano-cages (CNCs), and so on. The strengths and weaknesses of each nano-material are presented, as well as the challenging aspects that need to be addressed in future research. By comparing the applications and the current technology development, this review suggests utilizing artificial intelligence (AI) to screen suitable combinations of purification agents and performing virtual simulation experiments to verify the reliability of this methodology. By doing so, we aim to accelerate the development of new products and decrease the cost of innovation. It also recommends designing smarter pretreatment instruments to enhance the convenience and automation of the sample pretreatment process and reduce the margin for human error.

The method for the determination of imidaclothiz residue in tea by liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been developed. The imidaclothiz in tea was extracted by acetonitrile and purified by QuEChERS with PSA (primary secondary amine), C18, GCB (graphitized carbon black) as the adsorbents. The purified solution was centrifuged and the supernatant was diluted with water of equal volume. The separation was performed on a C18 column with a gradient elution program of acetonitrile (containing 0.1% (v/v) formic acid) and water at a flow rate of 0.30 mL/min. The mass spectrometer was carried out with electrospray ion source in the positive mode (ESI+) and selective reaction monitoring (SRM), quantified by external standard solution. The results showed that the mass concentration of imidaclothiz in the range of 1 to 500 μg/L was linearly correlated with the peak area, and the correlation coefficient (r) was 0.999 9. The limit of quantification (LOQ, S/N ≥ 10) was 0.01 mg/kg. The recoveries in oolong tea and green tea at three spiked levels (0.01, 0.3 and 3 mg/kg) varied from 87.0%-101.0% and the relative standard deviations (RSDs, n = 7) were between 2.1% and 13.1%. The real sample tests showed that the method is simple, cheap, accurate, specific, rapid, and suitable for the qualitative and quantitative confirmation of imidaclothiz residue in tea.