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A magnetic solid phase extraction (M-SPE) based on covalent organic framework materials coupled with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed for the efficient determination of four aflatoxins (AFs) in tea. The samples were extracted with a mixture of acetonitrile, water and glacial acetic acid (8.0:1.9:0.1, V/V) and centrifuged. The supernatant was evaporated to almost dryness, re-dissolved in water and pH adjusted, extracted M-SPE and filtered, and the filtrate was detected in the positive ion mode. The calibration curves for all analytes were linear in the range of 0.05–50 μg/L with coefficients of determination (R2) > 0.999 2, the spiked recoveries were in the range of 67.6%-103.7%, and the relative standard deviations (RSDs) for intra- and inter-day precisions were less than 9.24%, the limits of detection (LODs) were in the range of 0.01-0.06 μg/kg, and the limits of quantification (LOQs) of the developed method were in the range of 0.05-0.20 μg/kg. The covalent organic framework material prepared in this study has a strong adsorption capacity for AFs, and M-SPE-HPLC-MS/MS is suitable for the rapid, highly sensitive and accurate detection of AFs in tea.

Utilizing the microwave radiometer data and hourly rainfall data in Jilin Cloud Physics Field Scientific Test Base, CMA, the precipitation cloud system in Northeast China cold vortex at the Changbai Mountain foothills is analyzed. Rainfall events are divided into heavy precipitation, moderate intensity precipitation, and weak precipitation. Assisted by ERA5 reanalysis data, results show that the middle and high clouds appear first by 6 hours before the precipitation occurrence at the Changbai Mountain foothills. Water vapor and cloud water are both important for the occurrence and maintenance of heavy precipitation induced by Northeast China cold vortex. The cloud liquid water appears approximately with the height of 5-6 km by 4 hours before the precipitation induced by Northeast China cold vortex. Two hours before precipitation, the cloud descendes sharply. During one hour after the three types precipitation occurrence, the vapor density respectively leap to 13-14 g·m-3, 9-12 g·m-3, and 7-9 g·m-3 below 1 km height. Integrated water vapor during three types of precipitation increase to 5.8 cm, 4.2 cm, and 3.5 cm, respectively. The water vapor increases 5 hours before the occurrence of strong precipitation below 6 km height. The vapor density increases to 12-14 g·m-3 below 1 km height. There is cloud liquid water with 1.0-1.6 g·m-3 at the height of 5-6 km in the temperature layers of -5--10 ℃, which contributes to the formation of ice and snow crystals. Six hours before the heavy precipitation, moderate intensity precipitation, and weak precipitation, the integrated cloud liquid water are 4.2-4.8 mm, 3.0 mm, 2.3 mm, respectively. There are middle and high clouds in the temperature layers of -6 ℃ and -16 ℃. The height of cloud base drops sharply from 5.5-7 km to the ground, while the relative humidity drops sharply. These characteristics continue until the beginning of heavy rainfall. For moderate and weak precipitation induced by Northeast China cold vortex, there is middle cloud before the precipitation, and the cloud liquid water is 0.4-0.8 g· m-3 at the height of 5-6 km. However, there is no characteristic of water vapor jumping or relative humidity decreasing.Through the study of these physical quantity characteristics, indicators with indicative and predictive significance for precipitation induced by Northeast China cold vortex have been established.

Gelation, an important quality attribute of meat products, significantly influences the appearance, flavor, and texture of meat products. Enhancing gelation in meat products holds immense importance in improving the production process and the quality. The gel properties of meat products are influenced by the content and structure of protein aggregates and the aggregation rate during processing. Protein additives have the potential to partially replace myofibrillar proteins in gelation and emulsification properties, leading to cost reduction, and therefore have attracted much research interest for the development of new meat products and the optimization of the processing technology. This paper summarizes recent studies on the gelation mechanism of myofibrillar proteins, and reviews the properties and applications of the major protein additives as well as recent progress in using protein additives combined with polysaccharide colloids, enzymes or phosphates to enhance the gelation of meat products. This review may serve as a valuable reference for enhancing the quality of gel-type meat products.

Although previous studies have found that repeated exposure has an influence on the judgment of facial attractiveness, how this effect occurs remains unclear. Two experiments were conducted to explore the impact of repeated exposure on facial attractiveness and the processing mechanism. The results of Experiment 1 showed that in the case of large number of exposures, the facial attractiveness judgment for faces with high, moderate, and low attractiveness increased after repeated exposure. The increase in familiarity and liking mediated the relationship between repeated exposure and faces with high attractiveness, while the increase in liking mediated the relationship between repeated exposure and faces with low attractiveness. The results of Experiment 2 showed that in the case of small number of exposures, the facial attractiveness rating of faces with high and moderate attractiveness increased after repeated exposure. The increase in familiarity and liking mediated the relationship between repeated exposure and faces with high attractiveness, while the increase in familiarity mediated the relationship between repeated exposure and faces with moderate attractiveness. The results indicate that both the fluency of cognitive processing and change of affective attitude play an important role when people judge the facial attractiveness during repeated exposure. The present study illustrates the change rule of the evaluation of facial attractiveness, and lays a solid theoretical foundation for further investigation of the dynamic relationship between social characteristics of faces and behavioral decision-making., Author(s): Shangfeng Han [sup.1] [sup.2] , Jie Shen [sup.1] , Xiujuan Wang [sup.3] , Zhibin Guo [sup.1] , Shen Liu [sup.4] , Yetong Gan [sup.4] , Qiang Xu [sup.1] , [...]

The rotational spectrum of an acrolein–formaldehyde complex has been characterized using pulsed jet Fourier transform microwave spectroscopy complemented with quantum chemical calculations. One isomer has been observed in pulsed jets, which is stabilized by a dominant O=C⋯O tetrel bond (n → π* interaction) and a secondary C–H⋯O hydrogen bond. Splittings arising from the internal rotation of formaldehyde around its C2v axis were also observed, from which its V2 barrier was evaluated. It seems that when V2 equals or exceeds 4.61 kJ mol−1, no splitting of the spectral lines of the rotational spectrum was observed. The nature of the non-covalent interactions of the target complex is elucidated through natural bond orbital analysis. These findings contribute to a deeper understanding on the non-covalent interactions within the dimeric complex formed by two aldehydes. [ABSTRACT FROM AUTHOR]

ObjectiveTo understand the health information needs of chronic disease inpatients and the current utilization of community health resources， and to analyze the influencing factors， so as to provide basis for personalized and high-quality health education for chronic disease inpatients and to guide them to make full use of community health resources.MethodsFrom November 2020 to February 2021， we conducted a face-to-face multi-center clinical epidemiological survey with paper questionnaire in three general hospitals of Shanghai. The study included 404 inpatients with diabetes， hypertension， coronary heart disease， chronic respiratory diseases， cancer and other chronic diseases.Results94.01% of the 404 respondents had different needs for disease or health related information， and there was no significant difference between patients of different ages， genders and educational backgrounds in their needs for health knowledge. Among these patients， only 39.11% of them participated in the establishment of a card for chronic disease management in the community or signed for a family doctor. The participation rate of male patients was lower than that of female patients （P