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• Preston coefficient is affected by ultrasonic amplitude • Contact pressure is affected by ultrasonic amplitude • Large ultrasonic amplitude helps to improve the polishing ability • Local surface profile can be well predicted by the proposed calculation model • Prediction of surface profile is a basis for free-form surface polishing of UVAP With the rapid progress of science and technology, many applications of hard and brittle materials require advanced and suitable machining-techniques. One technique in particular, ultrasonic vibration-assisted polishing (UVAP), has been studied intensively by researchers worldwide. These studies indicate that UVAP has the capability to improve the surface quality as well as the machining efficiency. However, few studies focus on the deterministic material-removal of UVAP. The difference between generated and theoretical surface profiles determines the surface accuracy. Therefore, this paper focuses on predicting the generated local surface profile and providing a theoretical basis to reduce this error by controlling the polishing parameters. In addition to the axial ultrasonic vibration of polishing tool, ultrasonic atomization was adopted to provide uniformly distributed polishing slurry. To ensure sufficient surface-accuracy, it is necessary to predict the generated surface profile for a fixed spot as a basis research. This means, to enable accurate predictions the following improvements are realized: (i) A novel model for the elastic spherical contact-deformation of the polishing tool is used to calculate both the polishing force and contact radius. It takes into account the nonlinear elasticity of the polishing tool and the lateral extension of the contact area, which makes it more consistent with the actual deformation. (ii) A novel model for the material-removal distribution function for UVAP is proposed, based on the Preston equation. It considers the periodic changes of polishing force and contact radius caused by ultrasonic vibration. (iii) A series of fixed-spot polishing experiments on BK7 glass are carried out to verify the proposed models. The results show that the Preston coefficient is affected by axial ultrasonic amplitude, and large ultrasonic amplitude improves the polishing ability. In addition, the generated local surface profile, the maximum contact radius, as well as the material-removal depth and material-removal rate (MRR) can be predicted well. The new models not only provide a possibility to realize deterministic material removal but also enables in-depth-understanding of UVAP. It also represents a basic theoretical foundation for future, flat or free-form surface-polishing. [ABSTRACT FROM AUTHOR]

In the previous studies about grinding simulation, most of the abrasive grain models are simple geometries. The shape and size of the abrasive grain are varied, which will lead to the difference between the simulation and the reality. To make the virtual abrasive grains closer to reality, a stochastic polyhedral abrasive particle modeling method based on the ellipsoid tangent plane is proposed. Based on the ellipsoid model, the vertex coordinate equations of abrasive grain are derived. The 3D normal distribution is used to generate uniform random tangent points on the ellipsoid. The shape characteristics of normal virtual abrasive grains were analyzed, and the abnormal abrasive grains were corrected. The diameter of the minimum enclosed ball is used to calculate the equivalent diameter of the abrasive grain. According to the normal distribution, the abrasive grain sizes are scaled to the actual sizes. The coordinate transformation makes the abrasive grains more diverse. Finally, the influence of each input parameter on the virtual abrasive grain shapes is analyzed. And the shape distribution of actual and virtual abrasive grains is compared. The results show that the abrasive grain shape distribution can be effectively controlled through different generation strategies, and the model can simulate the actual abrasive grains effectively through the specific input strategy. [ABSTRACT FROM AUTHOR]

• Phosphorus application increased the yield of citrus plants by 32.6 % compared with the treatment without P fertilizer. • The increased yield was attributed to the increase in total number of fruits. • Soil acidification and aluminum toxicity to plants were likely the main constraints limiting the increase in yield. The objectives of the current study were to investigate the effects of nitrogen (N), phosphorus (P), and potassium (K) application rates on yield and quality of citrus fruits, and soil nutrient availability. The experiment was carried out using 8-year-old 'Navelina' navel orange (Citrus sinensis L. Osbeck) trees in an acid yellow sandy soil over three consecutive growing years in Zigui County in the Three Gorges Reservoir Area. This experiment consisted of 14 treatments with three factors (N, P, and K) and four levels of each factor. N application doses were 0, 66, 132, and 198 kg hm−2; P application doses were 0, 16.5, 33.0, and 49.5 kg hm−2; K application doses were 0, 27, 54, and 81 kg hm−2. P application at 49.5 kg hm−2 increased the yield of citrus by 32.6 % attributed to the increase in fruit number rather than mean fruit weight. P application did not affect total soluble solids of fruits when compared with the treatment without P application. Soil receiving 198 kg hm-2 of N rate revealed the lowest soil pH, which likely increased the toxicity of aluminum and then reduced citrus yield compared with the treatment without N fertilization. N and P application did not affect available N and available P in soils compared with treatments without N and P applications, respectively. We speculate that the increased fruit yield response of citrus trees by P fertilization is possibly due to aluminum detoxification as a result of phosphate complex with aluminum ions. [ABSTRACT FROM AUTHOR]

Leaf dark respiration (R dark ), an important yet rarely quantified component of carbon cycling in forest ecosystems, is often simulated from leaf traits such as the maximum carboxylation capacity (V cmax ), leaf mass per area (LMA), nitrogen (N) and phosphorus (P) concentrations, in terrestrial biosphere models. However, the validity of these relationships across forest types remains to be thoroughly assessed. Here, we analyzed R dark variability and its associations with V cmax and other leaf traits across three temperate, subtropical and tropical forests in China, evaluating the effectiveness of leaf spectroscopy as a superior monitoring alternative. We found that leaf magnesium and calcium concentrations were more significant in explaining cross-site R dark than commonly used traits like LMA, N and P concentrations, but univariate trait-R dark relationships were always weak (r 2  ≤ 0.15) and forest-specific. Although multivariate relationships of leaf traits improved the model performance, leaf spectroscopy outperformed trait-R dark relationships, accurately predicted cross-site R dark (r 2  = 0.65) and pinpointed the factors contributing to R dark variability. Our findings reveal a few novel traits with greater cross-site scalability regarding R dark , challenging the use of empirical trait-R dark relationships in process models and emphasize the potential of leaf spectroscopy as a promising alternative for estimating R dark , which could ultimately improve process modeling of terrestrial plant respiration., (© 2024 The Author(s). New Phytologist © 2024 New Phytologist Foundation.)

Purpose: In patients with gallstones complicated by common bile duct (CBD) stones, both normal and dilated common bile ducts have been reported. The goal of this study was to investigate the efficacy and safety of primary suturing after microincision of the cystic duct confluence in treating these patients., Method: Between July 2018 and December 2021, 104 patients were admitted to the Department of General Surgery at Guannan County People's Hospital with gallstone complications, and their records were reviewed retrospectively. The patients were divided into 2 groups: normal CBD group (n=70, CBD diameter: 6.0 to 8.0 mm) and dilated CBD group (n=34, CBD diameter: >8.0 mm). In these 104 patients, there were 75 cases of CBD stones with acute cholangitis, 12 cases of CBD stones without cholangitis, and 17 cases of mild biliary pancreatitis with CBD stones (including 2 cases of biliary pancreatitis with cholangitis). Among all patients, there were 37 cases with jaundice, 67 cases without jaundice, and 5 cases of emergency surgery. All patients underwent microincision of the cystic duct confluence followed by primary suturing. Both groups were compared on a variety of general and perioperative indicators., Result: All patients underwent laparoscopy combined with choledochoscopy; there were no cases of biliary tract injury or conversion to laparotomy. There was no statistically significant difference in operation duration ( P =0.286), blood loss ( P =0.06), length of stay ( P =0.821), and time to drainage tube removal ( P =0.096) between the 2 groups., Conclusion: Microincision of the cystic duct confluence, followed by a primary suture, is a safe and effective treatment for CBD stones in patients with a normal CBD diameter, as determined by preoperative imaging., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Introduction: Canopy species need to shift their ecological adaptation to improve light and water resources utilization, and the study of intraspecific variations in plant leaf functional traits based at individual scale is of great significance for evaluating plant adaptability to climate change., Methods: In this study, we evaluate how leaf functional traits of giant trees relate to spatial niche specialization along a vertical gradient. We sampled the tropical flagship species of Parashorea chinensis around 60 meters tall and divided their crowns into three vertical layers. Fourteen key leaf functional traits including leaf morphology, photosynthetic, hydraulic and chemical physiology were measured at each canopy layer to investigate the intraspecific variation of leaf traits and the interrelationships between different functional traits. Additionally, due to the potential impact of different measurement methods ( in-situ and ex-situ branch) on photosynthetic physiological parameters, we also compared the effects of these two gas exchange measurements., Results and Discussion: In-situ measurements revealed that most leaf functional traits of individual-to-individual P. chinensis varied significantly at different canopy heights. Leaf hydraulic traits such as midday leaf water potential (MWP) and leaf osmotic potential (OP) were insignificantly correlated with leaf photosynthetic physiological traits such as maximal net assimilation rate per mass ( A mass ). In addition, great discrepancies were found between in-situ and ex-situ measurements of photosynthetic parameters. The ex-situ measurements caused a decrease by 53.63%, 27.86%, and 38.05% in A mass , and a decrease of 50.00%, 19.21%, and 27.90% in light saturation point compared to the in-situ measurements. These findings provided insights into our understanding of the response mechanisms of P. chinensis to micro-habitat in Xishuangbanna tropical seasonal rainforests and the fine scale adaption of different resultant of decoupled traits, which have implications for understanding ecological adaption strategies of P. chinensis under environmental changes., 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 Jin, Yu, Dong, Duan, Mo, Feng, Bai, Zhao, Song, Dossa and Lu.)

Elevated atmospheric CO 2 (eCO 2 ) concentration can increase root exudation into soils, which improves plant tolerance to abiotic stresses. This review used a meta-analysis to assess effect sizes of eCO 2 on both efflux rates and total amounts of some specific root exudates, and dissected whether eCO 2 enhances plant's resistance to nutrient deficiency and ion toxicity via root exudates. Elevated CO 2 did not affect efflux rates of total dissolved organic carbon, a measure of combined root exudates per unit of root biomass or length, but increased the efflux amount of root systems per plant by 31% which is likely attributed to increased root biomass (29%). Elevated CO 2 increased efflux rates of soluble-sugars, carboxylates, and citrate by 47%, 111%, and 16%, respectively, but did not affect those of amino acids and malate. The increased carbon allocation to roots, increased plant requirements of mineral nutrients, and heightened detoxification responses to toxic ions under eCO 2 collectively contribute to the increased efflux rates despite lacking molecular evidence. The increased efflux rates of root exudates under eCO 2 were closely associated with improved nutrient uptake whilst less studies have validated the associations between root exudates and resistance to toxic ions of plants when grown under eCO 2 . Future studies are required to reveal how climate change (eCO 2 ) affect the efflux of specific root exudates, particularly organic anions, the corresponding nutrient uptake and toxic ion resistance from plant molecular biology and soil microbial ecology perspectives., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Crown Copyright © 2020. Published by Elsevier B.V. All rights reserved.)

Background: Elevated carbon dioxide (CO 2 ) and nitrogen (N) availability can interactively promote cucumber yield, but how the yield increase is realized remains unclear, whilst the interactive effects on fruit quality are unknown. In this study, cucumber plants (Cucumis sativus L. cv. Jinmei No. 3) were grown in a paddy soil under three CO 2 concentrations - 400 (ambient CO 2 ), 800 (elevated CO 2 , eCO 2 ) and 1200 µmol mol -1 (super-elevated CO 2 ) - and two N applications - 0.06 (low N) and 0.24 g N kg -1 soil (high N)., Results: Compared with ambient CO 2 , eCO 2 increased yield by 106% in high N but the increase in total biomass was only 33%. This can result from greater carbon translocation to fruits from other organs, indicated by the increased biomass allocation from stems and leaves, particularly source leaves, to fruits and the decreased concentrations of fructose and glucose in source leaves. Super-elevated CO 2 reduced the carbon allocation to fruits thus yield increase (71%). Additionally, eCO 2 also increased the concentrations of fructose and glucose in fruits, maintained the concentrations of dietary fiber, phosphorus, potassium, calcium, magnesium, sulfur, manganese, copper, molybdenum and sodium, whilst it decreased the concentrations of nitrate, protein, iron, and zinc in high N. Compared with eCO 2 , super-elevated CO 2 can still improve the fruit quality to some extent in low N availability., Conclusions: Elevated CO 2 promotes cucumber yield largely by carbon allocation from source leaves to fruits in high N availability. Besides a dilution effect, carbon allocation to fruits, carbohydrate transformation, and nutrient uptake and assimilation can affect the fruit quality. © 2018 Society of Chemical Industry., (© 2018 Society of Chemical Industry.)

Elevated atmospheric CO 2 (eCO 2 ) enhances the yield of vegetables and could also affect their nutritional quality. We conducted a meta-analysis using 57 articles consisting of 1,015 observations and found that eCO 2 increased the concentrations of fructose, glucose, total soluble sugar, total antioxidant capacity, total phenols, total flavonoids, ascorbic acid, and calcium in the edible part of vegetables by 14.2%, 13.2%, 17.5%, 59.0%, 8.9%, 45.5%, 9.5%, and 8.2%, respectively, but decreased the concentrations of protein, nitrate, magnesium, iron, and zinc by 9.5%, 18.0%, 9.2%, 16.0%, and 9.4%. The concentrations of titratable acidity, total chlorophyll, carotenoids, lycopene, anthocyanins, phosphorus, potassium, sulfur, copper, and manganese were not affected by eCO 2 . Furthermore, we propose several approaches to improving vegetable quality based on the interaction of eCO 2 with various factors, including species, cultivars, CO 2 levels, growth stages, light, O 3 stress, nutrient, and salinity. Finally, we present a summary of the eCO 2 impact on the quality of three widely cultivated crops, namely, lettuce, tomato, and potato.

In the title solvated mol-ecular salt, 2C4H12N5 (+)·CO3 (2-)·2CH3OH, the complete carbonate ion is generated by crystallographic twofold symmetry, with the C atom and one O atom lying on the rotation axis. The cation is twisted about the central C-N bond [C-N-C-N = -137.7 (6)°]. In the crystal, the components are linked by N-H⋯O, N-H⋯N and O-H⋯O hydrogen bonds, generating a three-dimensional supra-molecular network.

In the title compound, C(17)H(15)N(3)O(4), the mol-ecule is in the keto-hydrazone form. Intra-molecular N-H⋯O hydrogen bonds ensure that the mol-ecule is nearly planar (r.m.s. deviation of non-H atoms is 0.098 Å), with the two benzene rings forming a dihedral angle of 10.04 (2)°. In the crystal, inversion dimers are formed via pairs of O-H⋯O hydrogen bonds involving the -CO(2)H groups.

The asymmetric unit of the title compound, C(20)H(12)Cl(4)N(2)O(2), contains one half-mol-ecule with a center of symmetry along a C⋯C axis of the central benzene ring. The two C=O groups adopt an anti orientation and the two amide groups are twisted away from the central benzene ring by 27.38 (3) and 27.62 (4)°. The mean planes of the dichloro-substituted benzene rings are twisted by 7.95 (4)° with respect to the benzene ring. The crystal packing is stabilized by weak inter-molecular N-H⋯O inter-actions.