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Starch acetate was prepared from corn starch after ultra-high pressure (UHP) pretreatment at different pressure levels (100, 200, 300, 400, 500, and 600 MPa). The structural properties of UHP treated starch and starch acetate were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), rapid viscosity analysis (RVA) and differential scanning calorimetry (DSC). The results indicated that both UHP treatment and acetylation reaction resulted in swelling and rupture of starch granules. After UHP pretreatment, the relative crystallinity and gelatinization enthalpy of starch increased first and then decreased, reaching maximum values of 35.4% and 11.90 J/g at 400 MPa, respectively. Meanwhile, pasting parameters reached maximum values at this pressure level. After pretreatment at 600 MPa, the starch was gelatinized completely and the morphology of starch granules was destroyed. Furthermore, the crystalline structure changed from A-type to V-type. As a result, the degree of substitution and reaction efficiency of starch acetate significantly increased, reaching maximum values of 0.103 and 81.14%, respectively, when the pressure was 500 MPa. The occurrence of the maximum values might be related to the fact that the granular state was maintained despite obvious structural damage of starch granules, resulting in increased contact between starch granules and acetic anhydride. The findings of this study demonstrate that UHP pretreatment changes the structure of starch and thus helps increase the synthesis efficiency of starch acetate.

Cuproptosis is an emerging cell death pathway that depends on the intracellular Cu ions. Elesclomol (ES) as an efficient Cu ionophore can specifically transport Cu into mitochondria and trigger cuproptosis. However, ES can be rapidly removed and metabolized during intravenous administration, leading to a short half‐life and limited tumor accumulation, which hampers its clinical application. Here, the study develops a reactive oxygen species (ROS)‐responsive polymer (PCP) based on cinnamaldehyde (CA) and polyethylene glycol (PEG) to encapsulate ES‐Cu compound (EC), forming ECPCP. ECPCP significantly prolongs the systemic circulation of EC and enhances its tumor accumulation. After cellular internalization, the PCP coating stimulatingly dissociates exposing to the high‐level ROS, and releases ES and Cu, thereby triggering cell death via cuproptosis. Meanwhile, Cu2+‐stimulated Fenton‐like reaction together with CA‐stimulated ROS production simultaneously breaks the redox homeostasis, which compensates for the insufficient oxidative stress treated with ES alone, in turn inducing immunogenic cell death of tumor cells, achieving simultaneous cuproptosis and immunotherapy. Furthermore, the excessive ROS accelerates the stimuli‐dissociation of ECPCP, forming a positive feedback therapy loop against tumor self‐alleviation. Therefore, ECPCP as a nanoplatform for cuproptosis and immunotherapy improves the dual antitumor mechanism of ES and provides a potential optimization for ES clinical application. [ABSTRACT FROM AUTHOR]

Land urbanization has reduced the amount of area for natural ecosystem assets. However, with the development of the social economy, will the quality of natural ecosystem assets be improved? If one comprehensively considers the changes in the area and quality of natural ecosystem assets, is the dominant impact of urbanization on natural ecosystem assets positive or negative? In this study, detailed research is conducted on the area, pattern, quality, and overall situation of the ecosystem assets in the Beijing–Tianjin–Hebei urban agglomeration during the rapid urbanization process. The impact of urbanization on the overall situation of ecosystem assets is also analyzed. The research methods used to generate statistics, accounting, and analysis of the ecosystem assets include ArcGIS, satellite remote sensing images, R language programming, and other data analysis tools. The research results show that: (1) The ecosystem area was dominated by degradation, and the landscape pattern became increasingly fragmented, with the exception of farmland and wetland areas. (2) However, the quality of the natural ecosystem assets was significantly improved, and the overall situation of the natural ecosystem assets was optimized. (3) In addition to the population urbanization rate, the growth in the population density, land urbanization rate, and GDP per unit area had a significant negative impact on the overall situation of natural ecosystem assets. This reminds people that the improvement in asset quality can compensate for the reduction in area to some extent, and, in addition to the population urbanization rate, the levels of population density, land urbanization, and economic density should be appropriately controlled. [ABSTRACT FROM AUTHOR]

Ecosystem degradation can lead to adverse consequences and disasters and hence a healthy ecosystem is imperative for human well‐being. As a country with a large population and area, China's ecological security has global significance. To determine the effect of existing land use and relevant policies on the ecosystem, we need to understand the current situation of China's ecological degradation and restoration. However, relevant research at the national scale is lacking. We used remote sensing and GIS methods to study the extent, type, and composition of ecological degradation and restoration in China, at the national scale, from 2000 to 2015. The results revealed that the fundamental cause of China's ecological degradation was development and construction, and this kind of degradation is difficult to recover from. In the 15 years, the restoration area of this type of ecological degradation accounted for only 11% of the total degraded area. The total area that was newly constructed was 87,961.04 km2, of which 66,176.04 km2 was previously cultivated land. For food security, another 75,258.36 km2 of cultivated land was reclaimed. The two types of ecological degradation accounted for 71.59% of the total degraded area, and the increasing farmland area alone caused 42.14% of wetland degradation. Existing restoration projects are generally effective, but degradation, especially desertification, in the arid and semiarid regions of the northwest still needs special attention. Above all, ecological protection should be the focus, while ecological restoration the remedy. [ABSTRACT FROM AUTHOR]

Cyclocarya paliurusis a valuable medicinal tree species in China. However, limited information is available on its genotype selection and cultivation for improvement of growth and health-promoting phytochemicals. To contribute to improved knowledge of the potential use of the species, 33 families ofC. paliuruswere assessed with respect to genotype on growth and flavonoid content in the leaves, and the relationship between growth and flavonoid accumulation was examined. Growth and flavonoid content varied significantly among different families, and isoquercitrin was the main component of the individual flavonoids, followed by kaempferol and quercetin. Both total and individual flavonoids showed seasonal variation, with the mean highest contents of quercetin and isoquercitrin in July but the highest kaempferol content in October. Correlation analysis showed that tree height and diameter at breast height ofC. paliuruswere negatively correlated with the contents of quercetin and kaempferol in the leaves, whereas no significant correlation between tree growth and total flavonoid content was detected. Hierarchical cluster analysis based on the parameters of tree growth and leaf flavonoid contents indicated that 33 families ofC. paliuruswere classified into four distinct groups. Results from this study are valuable for identifying superior families for a specific site and provide a basis forC. paliurusbreeding strategies for flavonoid production. [ABSTRACT FROM PUBLISHER]

Natural gas infrastructure releases methane (CH4/, a potent greenhouse gas, into the atmosphere. The estimated emission rate associated with the production and transportation of natural gas is uncertain, hindering our understanding of its greenhouse footprint. This study presents a new application of inverse methodology for estimating regional emission rates from natural gas production and gathering facilities in north-eastern Pennsylvania. An inventory of CH4 emissions was compiled for major sources in Pennsylvania. This inventory served as input emission data for the Weather Research and Forecasting model with chemistry enabled (WRFChem), and atmospheric CH4 mole fraction fields were generated at 3 km resolution. Simulated atmospheric CH4 enhancements from WRF-Chem were compared to observations obtained from a 3-week flight campaign in May 2015. Modelled enhancements from sources not associated with upstream natural gas processes were assumed constant and known and therefore removed from the optimization procedure, creating a set of observed enhancements from natural gas only. Simulated emission rates from unconventional production were then adjusted to minimize the mismatch between aircraft observations and model-simulated mole fractions for 10 flights. To evaluate the method, an aircraft mass balance calculation was performed for four flights where conditions permitted its use. Using the model optimization approach, the weighted mean emission rate from unconventional natural gas production and gathering facilities in northeastern Pennsylvania approach is found to be 0.36% of total gas production, with a 2σ confidence interval between 0.27 and 0.45% of production. Similarly, the mean emission estimates using the aircraft mass balance approach are calculated to be 0.40% of regional natural gas production, with a 2σ confidence interval between 0.08 and 0.72% of production. These emission rates as a percent of production are lower than rates found in any other basin using a top-down methodology, and may be indicative of some characteristics of the basin that make sources from the north-eastern Marcellus region unique. [ABSTRACT FROM AUTHOR]

Abstract: The extraction conditions of procyanidins (PC) from the Chinese hawthorn (Crataegus pinnatifida Bge. var. major N.E.Br.) fruits were optimized by response surface methodology (RSM). Results showed that 93.4±0.21% of the PC could be recovered. The crude extract was then purified by using a LSA-10 resin column, which showed excellent adsorption and desorption properties for PC purification. A fraction with PC content above 83.2% and mainly consisting of EC, a singly-charged dimer and trimer as identified by HPLC/MS, was obtained by isolation on LSA-10 resin. The antioxidant activity of hawthorn PC was tested in vitro with different systems. In solution systems, the OH and O2 − scavenging ability of hawthorn PC were higher than vitamin C. In a liposome peroxidation system, hawthorn PC exhibited much higher antioxidant activity than vitamin E. In addition, hawthorn PC (0.02% w/v) was efficient to inhibit lipid peroxidation during enzymatic hydrolysis of porcine meat at 50°C for 24h. [Copyright &y& Elsevier]

Cyclocarya paliurus (Batal.) Iljinskaja is a plant with nutraceutical importance since its leaves have been used historically as folk medicines for hundreds of years. The content of 10 phenolic compounds was determined throughout the growing season by high-performance liquid chromatography (HPLC) with UV detector, while the antioxidant activities of C. paliurus leaf extracts were evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt radical cation (ABTS), and ferric reducing antioxidant power (FRAP) methods. Seasonal variations in phenolic concentration and antioxidant activity as well as linkage between the phenolic composition and antioxidant activity were assessed. A significant seasonal variation of phenolic compounds was observed in the leaves and the highest content appeared in May, July, and November. Seventy percent ethanol extract of C. paliurus leaves possessed a good radical scavenging potency. Meanwhile, a significant correlation between antioxidant activities and contents of phenolics was detected. Results of the relationship between molecular structures and their antioxidant activities showed that both the number and configuration of H-donating hydroxyl groups are the main structural features influencing the antioxidant capacity of phenolics, while glycosylation may reduce the antioxidant capacity. The information provided by this study not only revealed the accumulative dynamics of phenolic compounds, but also established a basis for determining the optimal time for harvesting to improve the content of beneficial compounds in the leaves of C. paliurus in the future. [ABSTRACT FROM AUTHOR]

Cyclocarya paliurus has been used commonly to treat diabetes in China. However, the effective components and the effect of plant origin remain unclear. In this study, C. paliurus leaves with different chemical compositions were selected from five geographical locations, and their effects on streptozotocin (STZ)-induced diabetic mice were evaluated with both ethanol and aqueous extracts. Glucose levels, lipid levels, and biomarkers of liver and kidney function were measured. The principal components of both C. paliurus ethanol and aqueous extracts from different geographical locations differed quantitatively and qualitatively. Results showed that C. paliurus extracts with better antihyperglycemic effects were characterized by higher contents of total flavonoids, especially quercetin-3-O-glucuronide and kaempferol-3-O-glucuronide. Furthermore, significantly negative correlations were found between triterpenoids contents and lipid levels. These results revealed the potential antihyperglycemic capacity of C. paliurus flavonoids and the antihyperlipidemic effect of C. paliurus triterpenoids. Thus, we suggest that the composition of C. paliurus compounds might help to design therapeutic alternatives for the treatment of diabetes mellitus. However, geographic origins and the extraction solvents can also affect the effectiveness of the treatment as these factors influence the chemical compositions and thereby the biological activities. [ABSTRACT FROM AUTHOR]