Transfer Learning with Optimal Transportation and Frequency Mixup for EEG-based Motor Imagery Recognition

Peer reviewedPublisher PD

Near-Earth injection of MeV electrons associated with intense dipolarization electric fields: Van Allen Probes observations.

Substorms generally inject tens to hundreds of keV electrons, but intense substorm electric fields have been shown to inject MeV electrons as well. An intriguing question is whether such MeVelectron injections can populate the outer radiation belt. Here we present observations of a substorm injection of MeV electrons into the inner magnetosphere. In the premidnight sector at L ∼ 5.5, Van Allen Probes (Radiation Belt Storm Probes)-A observed a large dipolarization electric field (50 mV/m) over ∼40 s and a dispersionless injection of electrons up to ∼3 MeV. Pitch angle observations indicated betatron acceleration of MeV electrons at the dipolarization front. Corresponding signals of MeV electron injection were observed at LANL-GEO, THEMIS-D, and GOES at geosynchronous altitude. Through a series of dipolarizations, the injections increased the MeV electron phase space density by 1 order of magnitude in less than 3 h in the outer radiation belt (L > 4.8). Our observations provide evidence that deep injections can supply significant MeV electrons

Experimental study and multi–objective optimization for drip irrigation of grapes in arid areas of northwest China

Grapes are the most important cash crop in Xinjiang. However, the effective utilization of agricultural water and fertilizer in this area is relatively low, which is very unfavourable for the development of Xinjiang grape industry. At present, there is a lack of research based on multi-objective water and fertilizer optimization to guide grape production. Field experiments were thus conducted over three consecutive years (2015–2017) to study the effects of water and fertilizer coupling on the yield, fruit quality, water use efficiency (WUE), fertilizer partial productivity (PFP), and net profits of Vitis vinifera cv. “Frey” grapes in northern Xinjiang. The optimum input range of water and fertilizer for multi-objective optimization were determined by using multiple regression and spatial analysis. Five levels of N–P2O5–K2O (180–225–495, 240–300–660, 300–375–825, 360–450–990, 420–525–1155 kg ha−1) were set up in the experiment, designated F60 %, F80 %, F100 %, F120 %, and F140 %, respectively. Three drip irrigation levels were designated W60 %, W80 %, W100 %, accounting for 60 %, 80 %, and 100 % of the ETc (where ETc denotes evapotranspiration under sufficient water supply for crops). The results show that at the same fertilization level, the leaf area index (LAI), vitamin C content, titratable acid, soluble solids content, dry matter yield, grape yield, PFP, and net profit increased with an increase in irrigation. They reached their maximum under full irrigation (W100 %). Compared to W80 % and W60 % irrigation levels, the WUE at a full (W100 %) irrigation was lower, but the PFP was the highest. The maximum grape bunch weight over three years was 407, 383, and 378 g, respectively. The highest harvest index (HI) was 0.460, 0.425, and 0.416, respectively. When the irrigation range was 334–348 mm and the N–P2O5–K2O fertilization range was 320–400–880∼392–490–1077 kg ha−1, the grape yield, net profit, WUE, vitamin C content, titratable acid content, and soluble solids content of the fruits reached more than 90 % of their maximum values simultaneously. The results of this research provide a scientific reference for water and fertilizer management of drip irrigation in Xinjiang vineyards.Grapes are the most important cash crop in Xinjiang. However, the effective utilization of agricultural water and fertilizer in this area is relatively low, which is very unfavourable for the development of Xinjiang grape industry. At present, there is a lack of research based on multi-objective water and fertilizer optimization to guide grape production. Field experiments were thus conducted over three consecutive years (2015–2017) to study the effects of water and fertilizer coupling on the yield, fruit quality, water use efficiency (WUE), fertilizer partial productivity (PFP), and net profits of Vitis vinifera cv. “Frey” grapes in northern Xinjiang. The optimum input range of water and fertilizer for multi-objective optimization were determined by using multiple regression and spatial analysis. Five levels of N–P2O5–K2O (180–225–495, 240–300–660, 300–375–825, 360–450–990, 420–525–1155 kg ha−1) were set up in the experiment, designated F60 %, F80 %, F100 %, F120 %, and F140 %, respectively. Three drip irrigation levels were designated W60 %, W80 %, W100 %, accounting for 60 %, 80 %, and 100 % of the ETc (where ETc denotes evapotranspiration under sufficient water supply for crops). The results show that at the same fertilization level, the leaf area index (LAI), vitamin C content, titratable acid, soluble solids content, dry matter yield, grape yield, PFP, and net profit increased with an increase in irrigation. They reached their maximum under full irrigation (W100 %). Compared to W80 % and W60 % irrigation levels, the WUE at a full (W100 %) irrigation was lower, but the PFP was the highest. The maximum grape bunch weight over three years was 407, 383, and 378 g, respectively. The highest harvest index (HI) was 0.460, 0.425, and 0.416, respectively. When the irrigation range was 334–348 mm and the N–P2O5–K2O fertilization range was 320–400–880∼392–490–1077 kg ha−1, the grape yield, net profit, WUE, vitamin C content, titratable acid content, and soluble solids content of the fruits reached more than 90 % of their maximum values simultaneously. The results of this research provide a scientific reference for water and fertilizer management of drip irrigation in Xinjiang vineyards

Anti-icing property of bio-inspired micro-structure superhydrophobic surfaces and heat transfer model

Ice accumulation is a thorny problem which may inflict serious damage even disasters in many areas, such as aircraft, power line maintenance, offshore oil platform and locators of ships. Recent researches have shed light on some promising bio-inspired anti-icing strategies to solve this problem. Inspired by typical plant surfaces with super-hydrophobic character such as lotus leaves and rose petals, structured superhydrophobic surface are prepared to discuss the anti-icing property. 7075 Al alloy, an extensively used materials in aircrafts and marine vessels, is employed as the substrates. As-prepared surfaces are acquired by laser processing after being modified by stearic acid for 1 h at room temperature. The surface morphology, chemical composition and wettability are characterized by means of SEM, XPS, Fourier transform infrared (FTIR) spectroscopy and contact angle measurements. The morphologies of structured as-prepared samples include round hump, square protuberance and mountain-range-like structure, and that the as-prepared structured surfaces shows an excellent superhydrophobic property with a WCA as high as 166 ± 2°. Furthermore, the anti-icing property of as-prepared surfaces was tested by a self-established apparatus, and the crystallization process of a cooling water on the sample was recorded. More importantly, we introduced a model to analyze heat transfer process between the droplet and the structured surfaces. This study offers an insight into understanding the heat transfer process of the superhydrophobic surface, so as to further research about its unique property against ice accumulation

Viral neutralization by antibody-imposed physical disruption

中和抗体是机体抵御病毒入侵的一类免疫球蛋白，也是疫苗发挥作用的主要效应分子。目前已知的中和抗体作用机制，主要包括阻断病毒-细胞相互作用和介导免疫调理作用。最近我校夏宁邵教授团队研究结果揭示了一种由抗体诱导病毒原位崩解的中和新机制。该研究首次揭示了抗体的直接物理碰撞中和机制，并提出诱导这类中和抗体的方法，有助于病毒保护性抗体和疫苗设计，适用于多种病原体，而不仅限于戊型肝炎病毒。分子疫苗学和分子诊断学国家重点实验室夏宁邵教授、李少伟教授和顾颖副教授为该论文的共同通讯作者，郑清炳博士、硕士生蒋婕、博士生何茂洲和郑子峥副教授为共同第一作者。In adaptive immunity, organisms produce neutralizing antibodies (nAbs) to eliminate invading pathogens. Here, we explored whether viral neutralization could be attained through the physical disruption of a virus upon nAb binding. We report the neutralization mechanism of a potent nAb 8C11 against the hepatitis E virus (HEV), a nonenveloped positive-sense single-stranded RNA virus associated with abundant acute hepatitis. The 8C11 binding flanks the protrusion spike of the HEV viruslike particles (VLPs) and leads to tremendous physical collision between the antibody and the capsid, dissociating the VLPs into homodimer species within 2 h. Cryo-electron microscopy reconstruction of the dissociation intermediates at an earlier (15-min) stage revealed smeared protrusion spikes and a loss of icosahedral symmetry with the capsid core remaining unchanged. This structural disruption leads to the presence of only a few native HEV virions in the ultracentrifugation pellet and exposes the viral genome. Conceptually, we propose a strategy to raise collision-inducing nAbs against single spike moieties that feature in the context of the entire pathogen at positions where the neighboring space cannot afford to accommodate an antibody. This rationale may facilitate unique vaccine development and antimicrobial antibody design.This research was supported by grants from the Natural Science Foundation of Fujian Province (Grant 2017J07005), the National Science and Technology Major Project of Infectious Diseases (Grant 2018ZX10101001-002), and the National Natural Science Foundation of China (Grants 81871247, 81991490, and 81571996).国家自然科学基金重大项目、海峡联合项目和面上项目、福建省自然科学杰出青年基金、国家传染病科技重大专项等资助了该项研究

Neutralization sites of human papillomavirus-6 relate to virus attachment and entry phase in viral infection.

Human papillomavirus type 6 (HPV6) is the major etiologic agent of genital warts and recurrent respiratory papillomatosis. Although the commercial HPV vaccines cover HPV6, the neutralization sites and mode for HPV6 are poorly understood. Here, we identify the HPV6 neutralization sites and discriminate the inhibition of virus attachment and entry by three potent neutralizing antibodies (nAbs), 5D3, 17D5, and 15F7. Mutagenesis assays showed that these nAbs predominantly target surface loops BC, DE, and FG of HPV6 L1. Cryo-EM structures of the HPV6 pseudovirus (PsV) and its immune complexes revealed three distinct binding modalities - full-occupation-bound to capsid, top-center-bound-, and top-rim-bound to pentamers - and illustrated a structural atlas for three classes of antibody-bound footprints that are located at center-distal ring, center, and center-proximal ring of pentamer surface for 5D3, 17D5, and 15F7, respectively. Two modes of neutralization were identified: mAb 5D3 and 17D5 block HPV PsV from attaching to the extracellular matrix (ECM) and the cell surface, whereas 15F7 allows PsV attachment but prohibits PsV from entering the cell. These findings highlight three neutralization sites of HPV6 L1 and outline two antibody-mediated neutralization mechanisms against HPV6, which will be relevant for HPV virology and antiviral inhibitor design. HighlightsMajor neutralization sites of HPV6 were mapped on the pseudovirus cryo-EM structuremAb 15F7 binds HPV6 capsid with a novel top-rim binding modality and confers a post-attachment neutralizationmAb 17D5 binds capsid in top-centre manner but unexpectedly prevents virus from attachment to cell surface

Viral neutralization by antibody-imposed physical disruption.

In adaptive immunity, organisms produce neutralizing antibodies (nAbs) to eliminate invading pathogens. Here, we explored whether viral neutralization could be attained through the physical disruption of a virus upon nAb binding. We report the neutralization mechanism of a potent nAb 8C11 against the hepatitis E virus (HEV), a nonenveloped positive-sense single-stranded RNA virus associated with abundant acute hepatitis. The 8C11 binding flanks the protrusion spike of the HEV viruslike particles (VLPs) and leads to tremendous physical collision between the antibody and the capsid, dissociating the VLPs into homodimer species within 2 h. Cryo-electron microscopy reconstruction of the dissociation intermediates at an earlier (15-min) stage revealed smeared protrusion spikes and a loss of icosahedral symmetry with the capsid core remaining unchanged. This structural disruption leads to the presence of only a few native HEV virions in the ultracentrifugation pellet and exposes the viral genome. Conceptually, we propose a strategy to raise collision-inducing nAbs against single spike moieties that feature in the context of the entire pathogen at positions where the neighboring space cannot afford to accommodate an antibody. This rationale may facilitate unique vaccine development and antimicrobial antibody design

Synthesis of Ruthenium (II) trisbipyridine complex containing ionic liquids immobilized on fibrous CoMn2O4 for isolation of asphaltene from petroleum

The formation of a durable nanoadsorbent, known as DFCoMn2O4/IL@Ru(II), was achieved by binding a complex of Ru (II) trisbipyridine with ionic liquids (IL) to a dendritic fibrous CoMn2O4 (DFCoMn2O4). The resulting DFCoMn2O4/IL@Ru(II) was characterized using various techniques such as X-ray diffraction analysis (XRD), fourier-transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), thermal gravimetric analysis (TGA), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), and scanning electron microscopy (SEM). DFCoMn2O4/IL@Ru(II) was then employed as an environmentally friendly adsorbent for the removal and adsorption of asphaltene from petroleum. The presence of fibrous CoMn2O4 categories enhanced the adsorption capacity and facilitated the recovery of the adsorbent without significantly reducing the efficiency. The results demonstrated a clear synergistic effect between dendritic fibrous CoMn2O4 and the IL@Ru(II) categories, exhibiting a strong correlation. The utilization of the DFCoMn2O4/IL@Ru(II) system resulted in quasi-second-order adsorption kinetics. The experiment was conducted using the Taguchi method to minimize costs and time. Various amounts of asphaltene, temperatures, and adsorbent quantities were examined. Minitab software was deployed to evaluate the impact of these variables on asphaltene adsorption. The presence of ionic liquid groups enhanced the solubility of the heterogeneous adsorbent in environmentally friendly solvents, thereby enhancing function and reducing the time

The Spatiotemporal Patterns of Climate Asymmetric Warming and Vegetation Activities in an Arid and Semiarid Region

Asymmetric warming was bound to have a major impact on terrestrial ecosystems in arid regions during global warming. Further study was necessary to reveal the spatiotemporal patterns of asymmetric warming in Xinjiang; this study analyzed the climate and normalized difference vegetation index (NDVI) data (2000–2020). The change trends of the day and nighttime warming (DNW), seasonal warming, and the diurnal temperature range in northern Xinjiang (S1) and southern Xinjiang (S2) were determined. The findings indicated that the DNW rate showed a significant (p < 0.05) upward trend, especially in winter. The nighttime warming rate (0.65 °C (decade)−1) was faster than the daytime warming rate (0.4 °C (decade)−1), and the diurnal temperature range between daytime and nighttime exhibited a decreasing trend. The diurnal temperature range was the highest in spring and the lowest in winter. Extreme values of the diurnal temperature range appeared in autumn (48.6 °C) and winter (12.3 °C) and both in S1. The Tmin in S1 had an abruption trend in 2006–2017, the Tmax in S2 had an abruption trend in 2005–2011, and the probability of spatial abruption in S1 was higher than that in S2. The partial correlation between the NDVI and Tmin was significantly higher than that between the NDVI and Tmax in the area where the significance test passed; therefore, asymmetric nighttime warming had a greater impact on the NDVI than the asymmetric daytime warming