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Recent magnetospheric observations and three‐dimensional (3D) kinetic simulations have shown that plasma wave activities are significantly enhanced around the reconnection x‐line, implying that the reconnection process is fully 3D. However, how the turbulence affects the local reconnection process has been poorly understood so far. We find by means of large‐scale particle‐in‐cell simulation in 3D system that the local reconnection rate can be significantly enhanced, reaching 0.4, which is much larger than theoretical predictions for two‐dimensional (2D) reconnection. The large reconnection rate is associated with large energy conversion rate and strong electron acceleration. The enhancement of the reconnection rate is caused by local increases of electron momentum transport and pressure gradient force induced by turbulence, which can not occur in 2D system. The result is expected to give better interpretations to in‐situ satellite observations where magnetic reconnection proceeds in 3D system. Plain Language Summary Magnetic reconnection is an important process in space physics to convert the magnetic field energy into particle kinetic energy. In this study, we investigate reconnection rate, a physical quantity that measures the speed of magnetic reconnection by using fully kinetic simulation, in which both electrons and ions are particles. We find very fast local reconnection processes in three‐dimensional system that far exceeds expectation. It indicates that magnetic reconnection is a three‐dimensional process. The high reconnection rate comes from the electrons rather than ions. And the main reason is the increasing of electron momentum transport and pressure gradient caused by strong turbulence, leading to a strong magnetic reconnection process in the current sheet. Key Points Magnetic reconnection can be strongly intensified in turbulent current sheet with the local reconnection rate exceeding 0.4 High reconnection rate is caused by local enhancements of electron momentum transport and pressure gradient force induced by turbulence Reconnection process is essentially 3D, suggesting that local satellite observations may be insufficient in capturing the global process

Nitric acid or qiangshui 强水 (\"strong liquid,\" from lat.aqua fortis) was introduced to China multiple times by European missionaries during the Ming and Qing dynasties.Xu Guangqi 徐光啟 (1562-1633) was the first Chinese to record related knowledge from his communication with Johann Schreck (1576-1630).Johann Adam Schall von Bell (1591-1666), Joachim Bouvet (1656-1730), and Matteo Ripa (1682-1746) independently described the substance to the Chinese in their writings, explaining production methods together with different applications such as separating and assaying of gold and silver, etching of iron or copperplates, and manufacturing of thermometers.This paper focuses on newly discovered Chinese materials, mainly from the Investigations of the Earth's Interior (Kunyu gezhi 坤輿格致, 1640) by Schall von Bell and his Chinese collaborators, but also from the Record of Essentials of Inception and Completion (Kaicheng jiyao 開成紀要) by Xu Guangqi.It analyzes different aspects of knowledge transmission processes including the identification of useful knowledge, the purpose of transmission, the sources of European knowledge, and the applied methods of translation and explanation.From these analyses we can better understand the reasons of their failure or success.

Although the effects of human disturbance on population genetic variation in plants have been widely studied, little attention has been paid to the impact of environmental changes on genetic dynamics after the implementation of conservation measures. Previously, freshwater Caohai Lake, famous for its abundant aquatic plants and birds, was strongly disturbed by tourism and other human activities; however, strict protective measures have been implemented since 2019. Therefore, the lake provides a suitable natural sampling ecosystem for investigating genetic variation changes following the implementation of conservation measures. Samples of cosmopolitan aquatic Ceratophyllum demersum were collected in 2019 and 2021, and they were analyzed using microsatellite primers. Our results show the presence of considerable genetic diversity in the C. demersum Caohai population. Although human disturbance decreased, the impact of natural disturbances, such as water flow and bird activities, persisted and may have increased. For C. demersum, water flow may cause vegetative propagules of different genotypes to pool in the downstream area of the lake. At sites with a very rich diversity of birds, increasing bird activities may augment the advantage of competitive clones in communities. Therefore, the continuous monitoring of the population’s genetic variation and the impact of related environmental factors is required for the efficient management of the lake ecosystem.

Background Iron oxide nanoparticles have been approved by food and drug administration for clinical application as magnetic resonance imaging (MRI) and are considered to be a biocompatible material. Large iron oxide nanoparticles are usually used as transversal ( T 2 ) contrast agents to exhibit dark contrast in MRI. In contrast, ultrasmall iron oxide nanoparticles (USPIONs) (several nanometers) showed remarkable advantage in longitudinal ( T 1 )-weighted MRI due to the brighten effect. The study of the toxicity mainly focuses on particles with size of tens to hundreds of nanometers, while little is known about the toxicity of USPIONs. Results We fabricated Fe 3 O 4 nanoparticles with diameters of 2.3, 4.2, and 9.3 nm and evaluated their toxicity in mice by intravenous injection. The results indicate that ultrasmall iron oxide nanoparticles with small size (2.3 and 4.2 nm) were highly toxic and were lethal at a dosage of 100 mg/kg. In contrast, no obvious toxicity was observed for iron oxide nanoparticles with size of 9.3 nm. The toxicity of small nanoparticles (2.3 and 4.2 nm) could be reduced when the total dose was split into 4 doses with each interval for 5 min. To study the toxicology, we synthesized different-sized SiO 2 and gold nanoparticles. No significant toxicity was observed for ultrasmall SiO 2 and gold nanoparticles in the mice. Hence, the toxicity of the ultrasmall Fe 3 O 4 nanoparticles should be attributed to both the iron element and size. In the in vitro experiments, all the ultrasmall nanoparticles (< 5 nm) of Fe 3 O 4 , SiO 2 , and gold induced the generation of the reactive oxygen species (ROS) efficiently, while no obvious ROS was observed in larger nanoparticles groups. However, the ·OH was only detected in Fe 3 O 4 group instead of SiO 2 and gold groups. After intravenous injection, significantly elevated ·OH level was observed in heart, serum, and multiple organs. Among these organs, heart showed highest ·OH level due to the high distribution of ultrasmall Fe 3 O 4 nanoparticles, leading to the acute cardiac failure and death. Conclusion Ultrasmall Fe 3 O 4 nanoparticles (2.3 and 4.2 nm) showed high toxicity in vivo due to the distinctive capability in inducing the generation of ·OH in multiple organs, especially in heart. The toxicity was related to both the iron element and size. These findings provide novel insight into the toxicology of ultrasmall Fe 3 O 4 nanoparticles, and also highlight the need of comprehensive evaluation for their clinic application. Graphical Abstract

In the field of rehabilitation, the electromyography (EMG) signal plays an important role in interpreting patients’ intentions and physical conditions. Nevertheless, utilizing merely the EMG signal suffers from difficulty in recognizing slight body movements, and the detection accuracy is strongly influenced by environmental factors. To address the above issues, multisensory integration-based EMG pattern recognition (PR) techniques have been developed in recent years, and fruitful results have been demonstrated in diverse rehabilitation scenarios, such as achieving high locomotion detection and prosthesis control accuracy. Owing to the importance and rapid development of the EMG centered multisensory fusion technologies in rehabilitation, this paper reviews both theories and applications in this emerging field. The principle of EMG signal generation and the current pattern recognition process are explained in detail, including signal preprocessing, feature extraction, classification algorithms, etc. Mechanisms of collaborations between two important multisensory fusion strategies (kinetic and kinematics) and EMG information are thoroughly explained; corresponding applications are studied, and the pros and cons are discussed. Finally, the main challenges in EMG centered multisensory pattern recognition are discussed, and a future research direction of this area is prospected.

The geometric and electronic structures and the bonding of U5M+ and T5M+ (U = uracil, T = thymine, M = Ag, Au) cluster cations have been investigated with density functional theory methods. They have a perfectly planar structure with C5h symmetry and significant stability, containing self-complementary N-H···O hydrogen bonds and five Au-O or Ag-O contacts. The energy gap between the LUMO and HOMO in the U5Ag+ cluster is 4.2 eV, which is twice as large as the HOMO-LUMO gap observed in the U5Au+ cluster. This notable difference clearly indicates that the U5Ag+ cluster possesses substantially greater stability compared to the U5Au+ cluster. This finding is consistent with the results from the energy decomposition analyses, which show that the total interaction energy of U5Ag+ is significantly higher than that of U5Au+. The same trend is observed in T5M+ as well. The interaction between the metal atoms, whether gold (Au) or silver (Ag), and the nucleobase is not predominantly controlled by electrostatic forces, as initially believed. Instead, it is primarily characterized by pronounced covalent bonding effects.

To address the challenges of difficult rock excavation and low mechanical breaking efficiency in vertical shafts, a gravity-driven shaft tunneling machine with improved adaptability for medium-hardness rock tunneling has been developed. By integrating numerical simulation and field testing, this study clarifies the dynamic rock-breaking mechanism of the cutter under the combined action of gravitational force and the tunneling machine’s rotational force. The approach aims to investigate the dynamic destruction process of rock under varying drum rotation speeds, analyzing rock crack development, crushing characteristics, and the variation laws of the cutter’s rolling and normal forces. Research results indicate that once the cutter of the new shaft tunneling machine penetrates the rock, driven by its self-gravity and the machine body’s rotational force, the tensile and shear stresses exerted on the rock exceed its inherent tensile strength, compressive strength, and shear strength thresholds. This leads to rock disintegration and separation from the main rock structure. The findings provide an effective reference for actual shaft construction projects.

Soil drought is detrimental to plant growth worldwide, particularly by triggering reactive oxygen species (ROS) burst. Serendipita indica ( Si ), a culturable root-associated endophytic fungus, can assist host plants in dealing with abiotic stresses; however, it is unknown whether and how Si impacts the drought tolerance of citrus plants. To unravel the effects and roles of Si on drought-stressed plants, trifoliate orange ( Poncirus trifoliata L. Raf.; a citrus rootstock) seedlings were inoculated with Si and exposed to soil drought, and growth, gas exchange, ROS levels, antioxidant defense systems, and expression of genes encoding antioxidant enzymes and fatty acid desaturases in leaves were measured. Soil drought suppressed plant biomass, whereas Si inoculation significantly increased plant biomass (10.29%-22.47%) and shoot/root ratio (21.78%-24.68%) under ample water and drought conditions, accompanied by improved net photosynthetic rate (105.71%), water use efficiency (115.29%), chlorophyll index (55.34%), and nitrogen balance index (63.84%) by Si inoculation under soil drought. Soil drought triggered an increase in leaf hydrogen peroxide and superoxide anion levels, while Si inoculation significantly reduced these ROS levels under soil drought, resulting in lower membrane lipid peroxidation with respect to malondialdehyde changes. Furthermore, Si -inoculated seedlings under soil drought had distinctly higher levels of ascorbate and glutathione, as well as catalase, peroxidase, and glutathione peroxidase activities, compared with no- Si -inoculated seedlings. Si inoculation increased the expression of leaf PtFAD2 , PtFAD6 , PtΔ9 , PtΔ15 , PtFe-SOD , PtCu/Zn-SOD , PtPOD , and PtCAT1 genes under both ample water and soil drought conditions. Overall, Si -inoculated trifoliate orange plants maintained a low oxidative burst in leaves under drought, which was associated with stimulation of antioxidant defense systems. Therefore, Si has great potential as a biostimulant in enhancing drought tolerance in plants, particularly citrus.

Flavonoids are the representative active substances of citrus with various biological activities and high nutritional value. In order to evaluate and utilize citrus flavonoids, isolation and purification are necessary steps. This manuscript reviewed the research advances in the extraction and purification of citrus flavonoids. The structure classification, the plant and nutritional functions, and the biosynthesis of citrus flavonoids were summarized. The characteristics of citrus flavonoids and the selection of separation strategies were explained. The technical system of extraction and purification of citrus flavonoids was systematically described. Finally, outlook and research directions were proposed. In order to evaluate and utilize citrus flavonoids, isolation and purification are necessary steps. In this review, the technical system of extraction and purification of citrus flavonoids was systematically described.

Electrospinning is a promising technique for preparing bioartificial blood vessels. Nanofibers prepared by electrospinning can simulate the structure of extracellular matrix to promote cell adhesion and proliferation. However, thorn-like protrusions can appear as defects on electrospun scaffolds and coaxial electrospun nanofibers often have no clear core/shell structure, which can seriously affect the quality of bioartificial blood vessels. To address these problems, Tween 80 is added to the electrospinning solution, which results in a stable Taylor cone, eliminates the thorn-like protrusions on electrospun bioartificial blood vessels, and reduces interfacial effects due to different core/shell solutions during coaxial electrospinning. Simulations, biomechanical tests, and in vivo studies were performed. The results demonstrate the excellent mechanical properties and biocompatibility of the bioartificial blood vessel. This research provides a useful reference for optimizing the electrospinning process for fabricating bioartificial blood vessels.