A Brief Review and Perspective on the Functional Biodegradable Films for Food Packaging

High-performance, environmentally-friendly biodegradable packaging as substitutes for conventional plastics becomes severe demand to nowadays economy and society. As an aliphatic aromatic copolyester PBAT is recognized as the preferred alternative to traditional plastics. However, the relatively high cost and weak properties obstacles the widespread adoption of PBAT. Modification pertaining to improve the properties, lower the cost, and include the functional additives of PBAT is a continuous effort to meet the needs of food accessibility, antibacterial properties, oxygen resistance, high mechanical strength, stable size, low moisture absorption, and various gas permeability for commercial competitiveness

Effect of moxibustion on the expression of GDNF and its receptor GFRα3 in the colon and spinal cord of rats with irritable bowel syndrome

Background: Moxibustion treatment has been found to ameliorate clinical symptoms including abdominal pain, diarrhoea and constipation in patients with irritable bowel syndrome (IBS). Herein we investigated the mechanisms underlying the use of moxibustion in a rat model of IBS. Methods: In our study, an IBS model was established in rats by colorectal distension (CRD) stimulus and mustard oil enema. The rats were randomly divided into a normal group, model group, mild moxibustion group, electroacupuncture group, probiotic group and dicetel group. Abdominal withdrawal reflex (AWR) scores were determined within 90 min of the last treatment. The expression of GDNF/GFRα3 protein and mRNA in the colon and spinal cord were detected by immunohistochemistry and quantitative real-time-PCR, respectively. Results: The IBS model rats had significantly higher AWR scores than the normal group (P<0.01). After mild moxibustion treatment, the AWR score was significantly reduced (20 mm Hg, P<0.05; 40 mm Hg, 60 mm Hg and 80 mm Hg, P<0.01). The model group showed significantly more colonic glial cell line-derived neurotrophic factor (GDNF/GFRα3 (GDNF family receptor α3) protein and mRNA expression in the colon and spinal cord than the normal group (P<0.01). Compared with the model group, the expression of GDNF/GFRα3 protein and mRNA in the colon and spinal cord of the rats were significantly decreased in the mild moxibustion group (colon: GDNF and GFRα3 protein, P<0.01; GDNF and GFRα3 mRNA, P<0.01; spinal cord: GDNF and GFRα3 protein, P<0.01; GDNF mRNA, P<0.05, GFRα3 mRNA, P<0.01). Conclusions: Our data suggest that moxibustion therapy may mitigate CRD-induced increases in the expression of GDNF and its receptor GFRα3 in the colon and spinal cord in a rat model of IBS

Total Phosphorus and Nitrogen Dynamics and Influencing Factors in Dongting Lake Using Landsat Data

Total phosphorus (TP) and total nitrogen (TN) reflect the state of eutrophication. However, traditional point-based water quality monitoring methods are time-consuming and labor-intensive, and insufficient to estimate and assess water quality at a large scale. In this paper, we constructed machine learning models for TP and TN inversion using measured data and satellite imagery band reflectance, and verified it by in situ data. Atmospheric correction was performed on the Landsat Top of Atmosphere (TOP) data by removing the effect of the adjacency effect and correcting differences between Landsat sensors. Then, using the established model, the TP and TN patterns in Dongting Lake with a spatial resolution of 30 m from 1996 to 2021 were derived for the first time. The annual and monthly spatio-temporal variation characteristics of TP and TN in Dongting Lake were investigated in details, and the influences of hydrometeorological elements on water quality variations were analyzed. The results show that the established empirical model can accurately estimate TP with coefficient (R2) ≥ 0.70, root mean square error (RMSE) ≤ 0.057 mg/L, mean relative error (MRE) ≤ 0.23 and TN with R2 ≥ 0.73, RMSE ≤ 0.48 mg/L and MRE ≤ 0.20. From 1996 to 2021, TP in Dongting Lake showed a downward trend and TN showed an upward trend, while the summer value was much higher than the other seasons. Furthermore, the influencing factors on TP and TN variations were investigated and discussed. Between 1996 and 2003, the main contributors to the change of water quality in Dongting Lake were external inputs such as water level and flow. The significant changes in water quantity and sediment characteristics following the operation of the Three Gorges Dam (TGD) in 2003 also had an impact on the water quality in Dongting Lake

Effects of Danqidihuang Granules on glucolipid metabolism in insulin-resistant rats

AbstractObjectiveTo explore whether the insulin resistance (IR) model could be established through feeding Sprague-Dawley (SD) rats high-sugar and high-fat diets and to further observe the preventive and treatment effects of different doses of Danqidihuang Granules in rats.MethodsThirty-two SD rats were divided randomly into control group A (given regular feed), model group B (food high in sugar and fat), intervention group C (food high in sugar and fat as well as regular doses of Danqidihuang Granules), and intervention group D (food high in sugar and fat as well as double doses of Danqidihuang Granules). The interventions were for 8 weeks. Motion, change in color, body weight, and food intake, as well as plasma lipids (including low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C), total cholesterol (TC) and triglyceride (TG), fasting blood glucose (FBG), fasting insulin (FINs) levels, insulin sensitivity index (ISI), and insulin resistance index (HOMO-IR) were observed.ResultsAt the end of the second week of the experiment, the appetite and activities of rats in groups B, C and D decreased significantly compared with group A. The fur of the rats in those three groups was curly. After the fourth week, the activities, food intake and color of rats in group B were worse than those in groups C and D, but there were no significant differences in weight (P>0.05). Compared with group A, LDL-C, TC, FBG and HOMO-IR in model group B were increased significantly (P<0.05), whereas the FINs and ISI increased obviously (P<0.05). The levels of LDL-C and TC in group D was decreased obviously compared with those in group C, and HOMO-IR in group D was less than that in group B (P<0.05).ConclusionsDanqidihuang Granules helped to prevent and improved the insulin resistance of rats

Modeling dust sources, transport, and radiative effects at different altitudes over the Tibetan Plateau

Mineral dust plays an important role in the climate of the Tibetan Plateau (TP) by modifying the radiation budget, cloud macro- and microphysics, precipitation, and snow albedo. Meanwhile, the TP, with the highest topography in the world, can affect intercontinental transport of dust plumes and induce typical distribution characteristics of dust at different altitudes. In this study, we conduct a quasi-global simulation to investigate the characteristics of dust source contribution and transport over the TP at different altitudes by using a fully coupled meteorology–chemistry model, the Weather Research and Forecasting model with chemistry (WRF-Chem), with a tracer-tagging technique. Generally, the simulation reasonably captures the spatial distribution of satellite-retrieved dust aerosol optical depth (AOD) at different altitudes. Model results show that dust particles are emitted into atmosphere through updrafts over major desert regions and then transported to the TP. The East Asian dust (mainly from the Gobi and Taklamakan deserts) is transported southward and is lifted up to the TP, contributing a mass loading of 50 mg m−2 at a height of 3 km and 5 mg m−2 at a height of 12 km over the northern slope of the TP. Dust from North Africa and the Middle East are concentrated over both of the northern and southern slopes below 6 km, where mass loadings range from 10 to 100 and 1 to 10 mg m−2 below 3 km and above 9 km, respectively. As the dust is transported to the north and over the TP, mass loadings are 5–10 mg m−2 above a height of 6 km. The dust mass flux carried from East Asia to the TP is 7.9 Tg yr−1, mostly occurring at heights of 3–6 km. The dust particles from North Africa and the Middle East are transported eastward following the westerly jet and then are carried into the TP at the west side with dust mass fluxes of 7.8 and 26.6 Tg yr−1, respectively. The maximum mass flux of the North African dust mainly occurs at 0–3 km (3.9 Tg yr−1), while the Middle Eastern dust occurs at 6–9 km (12.3 Tg yr−1). The dust outflow occurs on the east side (−17.89 Tg yr−1) and south side (−11.22 Tg yr−1) of the TP, with a peak value (8.7 Tg yr−1) at 6–9 km. Moreover, the dust (by mass) is concentrated within the size range of 1.25–5.0 µm and the dust (by particle number) is concentrated in the size range of 0.156–1.25 µm. Compared with other aerosols, the dust contributes to more than 50 % of the total AOD over the TP. The direct radiative forcing induced by the dust is −1.28 W m−2 at the top of the atmosphere (cooling), 0.41 W m−2 in the atmosphere (warming), and −1.68 W m−2 at the surface (cooling). Our quantitative analyses of the dust contributions from different source regions and the associated radiative forcing can help us to better understand the role of dust on the climate over the TP and surrounding regions