Development of a compact helicon plasma source with two sets of ring array permanent magnets for the study of blue core plasma.

A compact helicon plasma source for the study of helicon plasma, especially for the study of blue core plasma, is designed and developed with permanent magnets (PMs). The structure of the PMs consists of two sets of ring array magnets with opposite magnetization. This structure can provide a higher magnetic field with fewer PMs, which is helpful for controlling the device's mass. A quartz tube with 50 cm in length, 5 cm in outer diameter, and 0.3 cm in thickness is used. Argon helicon plasma is produced at ∼38 sccm (3.4 Pa inlet chamber and 0.122 Pa diffusion chamber) by a radio frequency (RF) power of ∼13.56 MHz using a helical antenna under a high magnetic field (∼1600 G). Preliminary results measured by the Langmuir probe, photomultiplier tube (PMT), CCD, and Hall coil are applied to characterize the helicon plasma in this source, such as the mode transition and the formation of the blue core with the RF power variation. The device generates the blue core (W mode) plasma at a lower power of about 200 W, and the energy coupling efficiency is as high as 65%.

Correction: Yang et al. Growing Carbon Nanotubes In Situ Surrounding Carbon Fiber Surface via Chemical Vapor Deposition to Reinforce Flexural Strength of Carbon Fiber Composites. Polymers 2023, 15, 2309.

In the original publication [...].

Growing Carbon Nanotubes In Situ Surrounding Carbon Fiber Surface via Chemical Vapor Deposition to Reinforce Flexural Strength of Carbon Fiber Composites.

This study employed novel joint treatments to strengthen the carbon fiber reinforced polymer (CFRP) composites. Vertically aligned carbon nanotubes (VACNTs) were prepared in situ on the catalyst-treated CF surface via the chemical vapor deposition (CVD) method, intertwining into three-dimensional fiber-nets and fully surrounding CF to form an integrated structure. The resin pre-coating (RPC) technique was further used to guide diluted epoxy resin (without hardener) to flow into nanoscale and submicron spaces to eliminate void defects at the root of VACNTs. Three-point bending testing results showed the "growing CNTs and RPC"-treated CFRP composites yielded the best flexural strength, a 27.1% improvement over the specimens without treatment, while the failure modes indicated that the original delamination failure was changed into "flexural failure" with through-the-thickness crack propagation. In brief, growing VACNTs and RPC on the CF surface enabled toughening of the epoxy adhesive layer, reducing potential void defects and constructing the integrated quasi-Z-directional fiber bridging at the CF/epoxy interface for stronger CFRP composites. Therefore, the joint treatments of growing VACNTs in situ via the CVD method and RPC technique are very effective and have great potential in manufacturing high-strength CFRP composites for aerospace applications.

In situ electrochemical synthesis of graphene-poly(arginine) composite for p-nitrophenol monitoring.

Para-Nitrophenol (p-nitrophenol) is a common industrial pollutant occurring widely in water bodies, yet actual monitoring methods are limited. Herein we proposed a fully electrochemically in situ synthesized graphene-polyarginine composite functionalized screen printed electrode, as a novel p-nitrophenol sensing platform. The electrode was characterized by morphologic, spectrometric and electrochemical techniques. p-nitrophenol in both pure aqueous solution and real water samples was tested. Results show a detection limit as low as the nanomolar level, and display a linear response and high selectivity in the range of 0.5-1250 µM. Molecular simulation reveals a detailed synergy between graphene and poly-arginine. The preferable orientation of nitrophenol molecules on the graphene interface in the presence of poly-arginine induces H- and ionic binding. This sensor is an ideal prototype for p-nitrophenol quantification in real waters.

Predicting copper contamination in wheat canopy during the full growth period using hyperspectral data.

The rapid and efficient determination of heavy metal content in food crops is essential for human health and environmental protection. The use of hyperspectral data has become a popular way to predict heavy metal content in plants; however, many challenges remain. One challenge is that lab conditions differ from actual agricultural production conditions. Another challenge is that spectral data characteristics are not universally applicable to all situations. Therefore, in this study, the field test method was adopted to conduct experiments during the full growth period of wheat, and the spectrum data of wheat canopy were processed by the first derivative method to screen-sensitive spectral bands as the basis for the prediction model of the copper content in wheat. The results showed that the copper content increased with an increase in the soil copper content, and there were dissimilar subtle differences in the spectral reflectance of wheat canopy under different stressed soil copper concentrations; sensitive spectral indices and wavelengths were screened based on good correlation with the copper content in the wheat canopy. Different optimal predicting models in different periods were built and verified. The established linear regression models, which were based on NDVI/SIPI and W728, were the most suitable predicting models during the tillering stage with R2 = 0.669 and 0.818; Rg, W741, and multiple bands were the most suitable predicting models during the jointing stage with R2 = 0.548, 0.830, and 0.868; the optimal model during the heading stage was based on W480 (R2 = 0.625). This study demonstrated that the constructed models had good potential for estimating the copper content in wheat leaves during full growth periods, and this method had the potential to be applied to the actual agricultural production process.

Non-alcoholic Fatty Liver Disease Induced by Perinatal Exposure to Bisphenol a Is Associated With Activated mTOR and TLR4/NF-κB Signaling Pathways in Offspring Rats.

Accumulating evidence suggests a role of bisphenol A (BPA) in non-alcoholic fatty liver disease (NAFLD), and its mechanism may be related to the up-regulation of lipogenic genes, but the mechanism of BPA induced lipogenic gene expression remains unknown. The aim of this study was to investigate the effects of perinatal exposure to BPA on NAFLD and its mechanisms. Pregnant Sprague-Dawley rats had access to drinking water containing 1 or 10 µg/ml BPA from gestational day 6 to post-natal day 21. For 5 weeks after weaning, offspring drank normal water without BPA. Body weight, lipid profile and the expression of genes or proteins involved in mTOR mediated lipid metabolism and autophagy, as well as inflammatory response were investigated in the 8-wk-old offspring of different genders. The results showed that body weight was increased only in females, however, males, and females from dams treated with BPA had significantly excess visceral adipose tissue, which was consistent with adipocyte hypertrophy. Elevated TG levels and up-regulation of lipogenic genes or proteins in liver, such as sterol regulatory element binding protein 1 (SREBP1), acetyl-CoA carboxylase 1 (ACC1), and fatty acid synthase (FAS) were consistent with increased liver lipid droplets in offspring exposed to BPA. Compared with controls, the protein levels of InsR, p-IRS-1, IRS-1, TSC1, and TSC2 were decreased, p-PI3K, p-Akt (S473), p-Akt (T308), p-mTOR, and mTOR were increased, and the impaired autophagic degradation was evidenced by increased protein levels of p62, although the levels of p-ULK1, Beclin1, and LC3B proteins were increased in liver of BPA-exposed offspring. The levels of TLR4 and NF-κB proteins were also significantly increased, and ERα protein was significantly decreased in BPA-exposed offspring. Our findings indicate that perinatal exposure to BPA causes the development of NAFLD in both female and male offspring, which is associated with up-regulation of lipogenic genes, dysregulated autophagy and activated inflammatory response involving the PI3K/Akt/mTOR and TLR4/NF-κB pathways.

Differentiation of clear cell and non-clear cell renal cell carcinomas by all-relevant radiomics features from multiphase CT: a VHL mutation perspective.

OBJECTIVES: To develop a radiomics model with all-relevant imaging features from multiphasic computed tomography (CT) for differentiating clear cell renal cell carcinoma (ccRCC) from non-ccRCC and to investigate the possible radiogenomics link between the imaging features and a key ccRCC driver gene-the von Hippel-Lindau (VHL) gene mutation. METHODS: In this retrospective two-center study, two radiomics models were built using random forest from a training cohort (170 patients), where one model was built with all-relevant features and the other with minimum redundancy maximum relevance (mRMR) features. A model combining all-relevant features and clinical factors (sex, age) was also built. The radiogenomics association between selected features and VHL mutation was investigated by Wilcoxon rank-sum test. All models were tested on an independent validation cohort (85 patients) with ROC curves analysis. RESULTS: The model with eight all-relevant features from corticomedullary phase CT achieved an AUC of 0.949 and an accuracy of 92.9% in the validation cohort, which significantly outperformed the model with eight mRMR features (seven from nephrographic phase and one from corticomedullary phase) with an AUC of 0.851 and an accuracy of 81.2%. Combining age and sex did not benefit the performance. Five out of eight all-relevant features were significantly associated with VHL mutation, while all eight mRMR features were significantly associated with VHL mutation (false discovery rate-adjusted p < 0.05). CONCLUSIONS: All-relevant features in corticomedullary phase CT can be used to differentiate ccRCC from non-ccRCC. Most subtype-discriminative imaging features were found to be significantly associated with VHL mutation, which may underlie the molecular basis of the radiomics features. KEY POINTS: • All-relevant features in corticomedullary phase CT can be used to differentiate ccRCC from non-ccRCC with high accuracy. • Most RCC-subtype-discriminative CT features were associated with the key RCC-driven gene-the VHL gene mutation. • Radiomics model can be more accurate and interpretable when the imaging features could reflect underlying molecular basis of RCC.

Changes of some anti-oxidative physiological indices under soil water deficits among 10 wheat (Triticum aestivum L.) genotypes at tillering stage.

Drought is one of the major ecological factors limiting crop production and food quality globally, especially in the arid and semi-arid areas of the world. Wheat is the staple food for more than 35% of world population and wheat cultivation is mainly restricted to such zones with scarcity of water, so wheat anti-drought physiology study is of importance to wheat production, food safety and quality and biotechnological breeding for the sake of coping with abiotic and biotic conditions. The current study is to investigate changes of anti-oxidative physiological indices of 10 wheat genotypes at tillering stage. The main results and conclusion of tillering stage in terms of activities of POD, SOD, CAT and MDA content as followed: (1) 10 wheat genotypes can be generally grouped into three kinds (A-C, respectively) according to their changing trend of the measured indices; (2) A group performed better drought resistance under the condition of treatment level 1 (appropriate level), whose activities of anti-oxidative enzymes (POD, SOD, CAT) were higher and MDA lower; (3) B group exhibited stronger anti-drought under treatment level 2 (light-stress level), whose activities of anti-oxidative enzymes were higher and MDA lower; (4) C group expressed anti-drought to some extent under treatment level 3 (serious-stress), whose activities of anti-oxidative enzymes were stronger, MDA lower; (5) these results demonstrated that different wheat genotypes have different physiological mechanisms to adapt themselves to changing drought stress, whose molecular basis is discrete gene expression profiling (transcriptom). The study in this respect is the key to wheat anti-drought and biological-saving water in worldwide arid and semi-arid areas; (6) POD, SOD, and CAT activities and MDA content of different wheat genotypes had quite different changing trend at different stages and under different soil water stress conditions, which was linked with their origin of cultivation and individual soil water threshold, which will provide better reference to selecting proper plant species for eco-environmental construction and crops for sustainable agriculture in arid and semi-arid areas.