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Poly(lactic acid) (PLA) biocomposites are usually plasticized to overcome the problem of poor ductility, which decreases the valuable tensile strength. In this study, novel nanofibrillated cellulose (NFC) was extracted to enhance the acetyl tributyl citrate (ATBC) plasticized PLA biocomposites. Interestingly, NFC not only exhibited an excellent strengthening effect but also showed a further toughening effect in the biocomposites. When 4 wt% NFC was added, the tensile strength, elongation at break, and impact strength of the biocomposites with 15 wt% ATBC and 20 wt% ATBC reached 52.6 MPa, 28.4%, 34.9 J/m and 35.8 MPa, 300.1%, 40 J/m, respectively. This is at least 1.1 folds higher in strength and 2.3 folds higher in impact toughness than the biocomposites without NFC. Glass transition and melting temperature slightly increased with NFC addition. More importantly, the mechanism of the strengthening and toughening effect was definitely elucidated, and the comprehensive performance of the application was evaluated. The findings of the study provide significant guidance for PLA application, such as in food packaging, medical engineering materials, and household products.

Vegetation restoration is one of the effective measures to deal with land degradation, and shrubs, as the pioneer plants, can improve soil conditions and accelerate the recovery of desertification. In recent decades, single‐scan (SS) and multiple‐scan (MS) modes have been widely used for forest inventories by terrestrial laser scanner (TLS) but TLS‐based shrub observation, and data quality uncertainties are less studied, especially in eco‐fragile regions with high survey costs and harsh environmental conditions. In this study, two shrub sample plots with different topographic characteristics were selected as the study area in the southern Qinghai‐Tibetan Plateau. We compared the basic phenotypic parameters (BPPs) under SS and MS mode, including number (N), height (H) and crown width (CW), to evaluate the potential of SS mode in extracting vegetation attributes. Through the distribution of shrub information loss rate (L) with distance and shrub height, the limitations of SS mode in obtaining data were discussed. By combining the topographic features of scanning spots, topographic relief (T) and L, we provided reasonable opinions on TLS collection mode, setting of scanning spots, and other operational aspects. The results indicated that: (1) SS mode has good applicability in shrub observation under different terrain characteristics. (2) The height distribution of the shrub is the main factor affecting the quality of data collection, and the information loss bias caused by distance should be considered only in the shrub plots with uniform height distribution. (3) T has an impact on shrub growth but has no effect on the quality of data acquisition (no significant correlation between T and L). These findings will provide technical support for TLS data collection on ecological restoration of degraded grassland dunes. [ABSTRACT FROM AUTHOR]

Global warming poses a serious threat to the alpine grassland on the Tibetan Plateau. Ecological restoration is an effective measure for adapting to climate change and controlling desertification. However, few studies have focused on the relationship between plant growth and the soil properties of valley-slope sand dunes during ecological restoration. We conducted a case study to investigate the changes in the soil properties at various elevations during two stages of ecological restoration. Our results indicated improvements in the plant growth and soil quality during the ecological restoration from 2011 to 2017. The soil particle size changed from predominantly medium-fine sand at stage 1 (2011) to very fine sand at stage 2 (2017). The soil organic matter and total N content ranged from 1.04–1.10 g·kg−1 and 0.06–0.07 g·kg−1 at different elevations in stage 1 and increased to 12.30–14.75 g·kg−1 and 2.82–3.08 g·kg−1, respectively, in stage 2. Higher plants were distributed mainly in the midslope area at stage 2. A significant positive correlation was observed between pH and plant height at stage 2. These findings improve our understanding of the changes in soils and plants on sandy land and their relationships during ecological restoration of alpine valleys. [ABSTRACT FROM AUTHOR]

The efficiency of ecosystem restoration of degraded land is typically assessed using vegetation structure parameters (VSP). However, the field measurement of VSP, particularly in the Qinghai–Tibet Plateau (QTP), which is a problematic area for ecological restoration because of its harsh environment, is generally time‐consuming and labour intensive. Therefore, new methods for VSP measurement should be developed. In this study, VSP were quantified at the individual scale, including their number, height, and crown width. Furthermore, the quadrat scale, such as vegetation coverage (VC) and leaf area index (LAI) on a restored sandy plot (100 m × 100 m) in the middle reaches of the Yarlung Zangbo River basin, is quantified using terrestrial laser scanning. Thereafter, the TLS‐derived VSP are validated by field measurements. To extract the VSP of low‐height vegetation (shrubs) at the individual scale, three approaches are tested: the manual measurement of VSP from TLS data, individual vegetation segmentation (IVS) without specific root locations, and IVS with specific root locations. The results indicate that the VSP of shrubs can be manually derived from the TLS data and are consistent with field measurements. By specifying the root locations before performing the IVS, the identification rate of the number of shrubs can be improved significantly from 40.3% to 100%. The height extracted by the IVS corresponds better with the manual measurement (R2 > 0.99) than with the crown width (R2 < 0.65). At the quadrat scale, the optimal resolution is analyzed to extract the VC. The analysis suggests that the optimal resolution for extracting the VC based on the canopy height model is in the 1‐2 cm range. In extracting the LAI using the voxel‐based method, it is discovered that the appropriate voxel size is linearly dependent on the mean point spacing (y = 2.143x, R2= 0.826). This study provides useful guidance for monitoring the effectiveness of ecological conservation and restoration on the QTP. [ABSTRACT FROM AUTHOR]

Nanofibrous poly(l‐lactic acid) (PLLA) microspheres are extensively studied to be used as cell carriers in the field of tissue engineering because the unique structure can promote cell proliferation and migration. But as injectable scaffold materials, PLLA microspheres easily run off to the soft tissue space because of the lack of cohesive force. It will affect the treatment efficiency and even cause additional inflammatory response. In order to overcome this disadvantage, superparamagnetic γ‐Fe2O3 nanoparticles assisted with oxidative polymerization of dopamine were used for surface modification of PLLA microspheres in this study. The results showed that this surface modification had no obvious cytotoxicity, and the modified microspheres possessed the ability to carry seed cells to controllably move to the defect sites with the guidance of magnetic field, which may be able to increase the repair efficiency. Moreover, the characteristic nanofibrous structure was not destroyed after modification, which was able to promote biological activity of cells. This work provides a novel way to produce superparamagnetic nanofibrous microspheres designed for cell microcarriers. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2018. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 511–520, 2019. [ABSTRACT FROM AUTHOR]

The main purpose of the paper is to analyze the conditional correlations, conditional covariances, and co-volatility spillovers between international crude oil and associated financial markets. The prices of oil and its interactions with financial markets make it possible to determine the associated prices of financial derivatives, such as carbon emission prices. The approach taken in the paper is different from others in the literature; the purpose is to examine the usefulness of modeling and testing volatility spillovers in the oil and financial markets. The paper investigates co-volatility spillovers (namely, the delayed effect of a returns shock in one physical or financial asset on the subsequent volatility or co-volatility in another physical or financial asset) between the oil and financial markets. The oil industry has four major regions, namely North Sea, the USA, Middle East, and South-East Asia. Associated with these regions are two major financial centers, namely the UK and the USA. For these reasons, the data to be used are the returns on alternative crude oil markets, returns on crude oil derivatives, specifically futures, and stock index returns in the UK and the USA. Given the importance of the Chinese financial and economic systems, the paper also analyzes Chinese financial markets, where the data are more recent. The USA and China are the world's two largest economies and the UK is the world's sixth largest economy (and second in the existing EU) behind the USA, China, Japan, Germany, and India. Moreover, the USA and the UK are associated with WTI and Brent oil, respectively. One of the purposes of the paper is to examine how China might be different from the USA and the UK, which seems to be borne out in the empirical analysis. Based on the conditional covariances to test the co-volatility spillovers, dynamic hedging strategies will be suggested to analyze market fluctuations in crude oil prices and associated financial markets. [ABSTRACT FROM AUTHOR]

Objective: To explore the impact of the level of differentiation in a minimum of two follicles with a diameter of ≥18 mm on the outcome of controlled ovarian hyperstimulation on the day of human chorionic gonadotropin (hCG) administration., Methods: Single-center data from January 2018 to December 2021 was retrospectively analyzed for 1,199 patients with fresh embryo transfer for assisted reproduction. The absolute value of the standard deviation of the follicle size of at least 2 follicles ≥18 mm in diameter in both ovaries on the day of hCG was taken as the degree of differentiation of the dominant follicle after ovulation induction, based on the standard deviation response to the degree of dispersion of the data. The degree of follicular differentiation was divided into 3 groups according to the size of the value, and the general clinical conditions, laboratory indexes, and clinical outcomes of the patients in the 3 groups were compared., Results: Among the three groups, the body mass index (BMI) of the ≤1s group was lower than that of the other two groups (P< 0.05), while the follicle-stimulating hormone (FSH) and Anti-Mullerian hormone (AMH) were higher (P< 0.05), and the implantation rate and clinical pregnancy rate were significantly higher than those of the other two groups (P< 0.01). After multifactorial logistic regression to correct for confounding factors, with the ≤1s group as the reference, the implantation rate, hCG-positive rate, clinical pregnancy rate and live birth rate of embryo transfer in the ≥2S group were significantly lower (P< 0.01). The results of curve fitting analysis showed that the live birth rate decreased gradually with the increase of the absolute standard deviation (P=0.0079)., Conclusion: Differences in follicle diameters ≥18 mm on the day of hCG injection did not have an impact on embryo quality, but had an impact on pregnancy outcomes. The less the variation in follicle size, the more homogeneous the follicle development and the higher the likelihood of live births., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Xu, Chen, Tian, Chen, Zhang, Li, Wu, Zhang and Zhang.)

Nanofibrous poly(l-lactic acid) (PLLA) microspheres are extensively studied to be used as cell carriers in the field of tissue engineering because the unique structure can promote cell proliferation and migration. But as injectable scaffold materials, PLLA microspheres easily run off to the soft tissue space because of the lack of cohesive force. It will affect the treatment efficiency and even cause additional inflammatory response. In order to overcome this disadvantage, superparamagnetic γ-Fe 2 O 3 nanoparticles assisted with oxidative polymerization of dopamine were used for surface modification of PLLA microspheres in this study. The results showed that this surface modification had no obvious cytotoxicity, and the modified microspheres possessed the ability to carry seed cells to controllably move to the defect sites with the guidance of magnetic field, which may be able to increase the repair efficiency. Moreover, the characteristic nanofibrous structure was not destroyed after modification, which was able to promote biological activity of cells. This work provides a novel way to produce superparamagnetic nanofibrous microspheres designed for cell microcarriers. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2018. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 511-520, 2019., (© 2018 Wiley Periodicals, Inc.)