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The problem of food-borne illnesses due to microbial contamination of infant and young children foods is usually of international concern， and the unique character of the infant and young child population requires special and strict food safety requirements for their own foods. This article reviews the progress of contamination with Salmonella and Cronobacter （Enterobacter sakazakii） of Enterobacteriaceae family in foods for infants and young children and its diseases risk at home and abroad in recent years， and also provides technical support for the revision of national standards for infant and young children foods and its manufacturing processes in China through the comparative analysis of domestic and international microbiological limits for infant and young children foods.

ObjectiveThe sampling method of virus on food packaging surfaces was optimized. The virus recovery rate on different material surfaces was studied by simulating different scenes of virus contamination on the surfaces of frozen food packaging materials.MethodsThe virus was evenly coated on the surfaces of different materials in different scenarios. Different buffers and different sampling methods were used for sampling residual virus. The virus recovery rate was calculated by virus titer （TCID50）.ResultsAmong the three sample buffers， Hank’s balanced salt solution had the highest virus recovery rate， followed by PBS buffer and MEM media. Among the five sampling methods， the highest recovery was to apply the wet swab once on the surface and then rotated for the next swabing. Using the optimized sampling method to sample virus from the surfaces of different materials， the recovery rates of smooth plastic surface and metal surface were 10.47% and 3.55%， while the living virus of hard plastic surface， thick cardboard surface， kraft paper and wood surface could not be collected. The virus recovery rates of contaminated food on smooth plastic surface before and after frozen were 92.03% and 4.83%， and that of and metal surface were 1.27% and 4.94%. In addition， the recovery rate of hard plastic surface was 2.59% in contaminated food before frozen， and the recovery rate of thick cardboard surface was 1.27% only in the contaminated food after frozen.ConclusionThe virvs recovery rates varies depending on the substrate of surfaces. This sampling method is suitable for collecting virus from smooth "hard surfaces". The residual virus on frozen food packaging surfaces can be effectively collected by the sampling method optimized above as well.

ObjectiveTo investigate and analyze the contamination of 12 mycotoxins in unprocessed wheat grain samples from four provinces of China in 2019.MethodsA total of 289 wheat grain samples harvested in 2019 from He'nan, Hebei, Anhui and Shandong provinces of China were collected and analyzed for 12 kinds of mycotoxins, including 8 Fusarium toxins and 4 aflatoxins by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS).ResultsDeoxynivalenol (DON) was the predominant mycotoxin in wheat samples, and the positive rate and the average level of DON were 95.5% (276/289) and 135.9 μg/kg. While the positive rates and the average levels of 15-acetyl-deoxynivalenol (15-Ac-DON) and 3-acetyl-deoxynivalenol (3-Ac-DON) were 37.4% (108/289) and 4.4 μg/kg, 36.7% (106/289) and 5.2 g/kg, respectively. The positive rates and the average levels of the rest of 8 Fusarium toxins and 4 aflatoxins were relatively low. There was no significant difference in mycotoxins contamination levels among the four provinces. Among 289 wheat samples, 59.9% (173/289) samples were simultaneously contaminated with more than 2 mycotoxins with DON and its derivatives 15-Ac-DON and/or 3-Ac-DON being the frequent combination.ConclusionDON is the predominant mycotoxin in wheat samples in China and the incidence of co-occurrence of DON and its derivatives, 3-Ac-DON and/or 15-Ac-DON are high. The positive rate and contamination levels of aflatoxins and other Fusarium toxins are relatively low. These results suggest that there should be a continuous monitoring for the contamination of fusarium mycotoxins, especially DON and its derivatives, in wheat in China.

All‐solid‐state lithium metal batteries (ASSLMBs) hold great promise for the development of next‐generation high‐safety, high‐energy‐density lithium batteries, but still face the challenges of lithium dendrite growth and thickness. Herein, the ultrathin PEO‐based composite solid polymer electrolyte (denoted as PAL) supported by a low‐density self‐supporting aramid nanofiber (ANF) aerogel framework is developed. The ANF aerogel obtained by a novel CO2‐assisted induced self‐assembly method has a well‐designed bilayer structure with double cross‐linking degree. Benefiting from the intermolecular interaction between ANFs and PEO, the PAL achieves an ultrathin thickness (20 µm) with excellent thermal stability and mechanical strength. Meanwhile, due to the modulation of ionic pathways by the functionalized ANF, the PAL achieves uniform lithium deposition without dendrites, resulting in stable long cycling (1400 h) for symmetric cells. Consequently, the Li|PAL|LiFePO4 (LFP) cell has excellent long‐term cycling stability (1 C, >700 cycles, Coulombic efficiency > 99.8%) and fast charge/discharge performance (rate, 10 C). More practically, the Li|PAL|LFP cell achieves an energy density of 180 Wh kg−1 due to the ability to match a high‐loading (8 mg cm−2) cathode. Furthermore, the double‐layer Li|PAL|LFP pouch cell demonstrates excellent flexibility and safety in cycling and abuse tests. [ABSTRACT FROM AUTHOR]

Magnetic MXene-based composites have been extensively developed for highly effective electromagnetic (EM) wave absorption. However, previously reported studies neglected the influence of regulating primary dissipation sources and electron migration on absorption performance. This is probably due to the fact that the present modification methods frequently severely oxidize MXenes, obliterating the electron migration pathway. Here, a facile strategy is developed to create sandwich-like m-Ti3C2/Fe3O4 (MTF) composites by electrostatic assembly. The room temperature assembly process prevents oxidation and safeguards the in-plane electron migration path of m-Ti3C2. This makes it possible to reveal the mechanism by which increased Fe3O4 content inhibits electron migration, lowers attenuation capacity, and leads to increasing impedance-matching thickness. More importantly, we provide the first explanation of the absorption band transfer phenomenon. Additionally, at a thickness of 2.96 mm, the as-prepared MTF composites exhibit exceptional EM wave absorption capacity, reaching −77.5 dB with an effective absorption band of 3.0 GHz. The comprehensive insight presented in this work offers a solid theoretical foundation for an in-depth understanding of the influence of electron hopping behaviors on electromagnetic characteristics and, consequently, EM wave absorption performance, which further offers an essential roadmap to fabricate high-performance absorbers. [ABSTRACT FROM AUTHOR]

Land-use change plays an important role in ecological change; knowing the trends in land-use change can quickly help identify problems in regional ecosystems. In 2000 to 2020, the development of a global economy caused increasing extreme weather events worldwide and lead to exacerbating changes in types of land-use. The Yellow River source area is an important water source and a central part of ecological protection efforts in China. The fragile ecosystems make the area sensitive to environmental changes. Therefore, in protecting the ecological security of the basin, simulating changes in the ecosystem service value under different scenarios is a meaningful procedure. A patch-generating land use simulation model was used to simulate different land use scenarios in 2030, including an ecological protection scenario, a production priority scenario, a carbon neutral scenario and a natural development scenario. The analysis shows that significant progress has been made in water conservation but grassland conservation faces enormous challenges. The rate of development, occupation of farmland and land dedicated to construction has increased. Unused land increased dramatically from 2010–2020 and has not been mitigated by existing policies. Based on the unit area value equivalent coefficients, the ecosystem service value rankings for the seven land use types were as follows: Grassland > Wetland > Water Area > Forest > Farmland > Unused Land > Construction Land; the four types of ecosystem service value are ranked as follows: regulating services > supporting services > supply services > cultural services; the four scenarios of ecosystem service value are ranked as follows: ecological protection scenario > production priority scenario > carbon neutral scenario > natural development scenario. The ecosystem service value of the Yellow River source area would increase by CNY 1.641 billion in 2030 with ecological protection goals and decrease by CNY 1.421 billion with the current of development. This study provides valuable insights and implications for land use, ecological protection and sustainable development by shedding light on watershed change issues and assessing and predicting the ecological status of the Yellow River source area. [ABSTRACT FROM AUTHOR]