Dipolarizing flux bundles transport magnetic flux to the inner and dayside magnetosphere, heat the plasma sheet, and provide a seed population to the radiation belt. The magnetic perturbation ahead ...of them, often referred to as a dipolarization front (DF), is asymmetric with a small Bz dip followed by a sharp Bz enhancement. The Bz dip is thought to be generated from dawnward currents carried by DF‐reflected ions; after reflection, these earthward moving ions gyrate clockwise and contribute to dawnward diamagnetic currents ahead of the front. Using observations of hundreds of DFs, we investigate this hypothesis. We find that the depth of the Bz dip as a function of the front azimuth depends on DF propagation speed and ambient plasma density. These statistical signatures support the hypothesis that the Bz dip is caused by ion reflection and suggest that secondary currents carried by these reflected ions can reshape the front significantly.
Key Points
Dawnward currents carried by DF‐reflected ions can generate precursor Bz dips
Predicted signatures of Bz dips are consistent with statistical results
Distortion of moving flux tubes is explained without invoking other mechanisms
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•Polycationic coatings are efficiently fabricated via co-deposition and N-alkylation.•The optimized membrane surfaces exhibit over 95% bacterial inhibition.•The positively charged ...coatings also show low adhesion of BSA and S.aureus cells.
Biofouling control is a major task in membrane separation processes for water treatment and biomedical applications. In this work, N-alkylated polyethylenimine (PEI) is facilely and efficiently introduced onto the membrane surfaces via the co-deposition of catechol (CCh) and PEI, followed by further grafting of PEIs (600Da, 70kDa and 750kDa) and cationization with methyl iodide (CH3I). The physical and chemical properties of the constructed membrane surfaces are characterized with scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, zeta potential and water contact angle measurements. Antibacterial assay reveals that the optimized membrane surfaces possess around 95% antibacterial efficiency against Gram-positive Staphylococcus aureus (S. aureus) with weak adhesion of bacteria cells after 24h of bacterial contact. Additionally, the membrane surfaces also exhibit much enhanced antifouling property during the filtration of opposite charged bovine serum albumin (BSA). These results demonstrate a useful strategy for the surface modification of separation membranes by a kind of antimicrobial and antifouling coating.
Long noncoding RNAs (lncRNAs) have been demonstrated to play significant roles in non-small cell lung cancer (NSCLC) progression. Recently, a newly identified lncRNA, LncRNA LINC00668 (LINC00668), ...was reported to be involved in the regulation of progression of several tumors. However, the expression pattern and biological function of LINC00668 in NSCLC remains largely unclear. In this study, we found that LINC00668 expression was significantly up-regulated in both NSCLC tissues and cell lines. we also showed that LINC00668 upregulation was induced by transcription factor STAT3. Clinical investigation demonstrated that high expression level of LINC00668 was associated with advanced TNM stage, histological grade and lymph node metastasis. Moreover, multivariate analysis confirmed LINC00668 expression level to be an independent prognostic indicator for overall survival of NSCLC patients. Functional assays indicated that knockdown of LINC00668 suppressed NSCLC cells proliferation, migration and invasion, and promoted apoptosis. Mechanistic studies indicated that LINC00668 is a direct target of miR-193a, leading to down-regulation in the expression of its target gene KLF7. Our findings suggested that STAT3-induced LINC00668 contributed to NSCLC progression through upregulating KLF7 expression by sponging miR-193a, and may serve as a prognostic biomarker and a potential target for NSCLC.
This study investigated the pyrolysis of plant acidified oil, aiming to upgrade the quality of oil for fuel use. The decomposition temperature of plant acidified oil was in the range of 300oC-500 °C ...in 10 K/min according to TG-DTG. The Py-GC-MS results showed that except alkane, alkene and oxygen containing compound, plant sterol derivatives were also detected. The ESI FT–ICR MS results showed the presence of some products produced from hydrogenation and polymerization reaction occurred in pyrolysis process. The yield of the liquid product reached the maximum of 90% at 500 °C. The acid value and viscosity of pyrolysis products were relative high compared with diesel oil. The calorific value has no difference with that of diesel oil. According to above experiments, it was confirmed that pyrolysis components and characteristic of plant acidified oil was different with vegetable oil or fatty acid. Plant acidified oil was potential renewable source to obtain bio-fuel oil using pyrolysis method.
•Plant acidified oil was first reported as a renewable source to obtain bio-fuel oil using cracking method.•According to ESI FT-ICR MS results, it was found that hydrogenation and polymerization process occurred in pyrolysis process.•The pyrolysis products of plant acidification oil were different with vegetable oil or fatty acid.
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•An AIRE-active hydrazone-based fluorescent probe with endoplasmic reticulum-targeting ability has been developed.•The probe could act as a fluorescent ratiometric chemsensor for ClO− ...detection.•The probe responded to ClO− with a short response time (within 20 s) and a lower detection limit (15.4 μM).•The probe has been successfully applied to the imaging of ClO− in the endoplasmic reticulum of living cells and zebrafish.
Hypochlorite (ClO−) plays an important role in the human immune defense system, but high concentrations of ClO− in the endoplasmic reticulum (ER) damage cellular proteins, causing ER stress, cell death, and various diseases. Herein, we developed a simple hydrazone probe (1) featuring aggregation-induced ratiometric emission, which would quickly (within 20 s) and sensitively (detection limit of 15.4 μM) respond to ClO− in an almost pure aqueous solution via a fluorescent ratiometric output. Furthermore, the probe was employed to track the level of ClO− in the ER of HeLa cells and zebrafish.
The existence of planetary radiation belts with relativistic electron components means that powerful acceleration mechanisms are operating within their volume. Mechanisms that bring charged particles ...planetward toward stronger magnetic fields can cause their heating. On the basis that electron fluxes in Saturn's radiation belts are enhanced over discrete energy intervals, previous studies have suggested that rapid inward plasma flows may be controlling the production of their most energetic electrons. However, rapid plasma inflows languish in the planet's inner magnetosphere, and they are not spatially appealing as a mechanism to form the belts. Here we show that slow, global-scale flows resulting from transient noon-to-midnight electric fields successfully explain the discretized flux spectra at quasi- and fully relativistic energies, and that they are ultimately responsible for the bulk of the highest energy electrons trapped at Saturn. This finding is surprising, given that plasma flows at Saturn are dominated by the planetary rotation; these weak electric field perturbations were previously considered impactful only over a very narrow electron energy range where the magnetic drifts of electrons cancel out with corotation. We also find quantitative evidence that ultrarelativistic electrons in Jupiter's radiation belts are accelerated by the same mechanism. Given that similar processes at Earth drive a less efficient electron transport compared to Saturn and Jupiter, the conclusion is emerging that global-scale electric fields can provide powerful relativistic electron acceleration, especially at strongly magnetized and fast-rotating astrophysical objects.
A series of diamide derivatives containing α‐amino acids were designed and synthesized. These compounds were evaluated for their insecticidal activities against Plutella xylostella, Mythimna ...separate, Myzus persicae, and Tetranychus cinnabarinus. Most of the title compounds containing an l‐phenylglycine skeleton were endowed with good activities at the concentration of 500 mg·L−1. Compounds (R)‐A6 showed a potential value for further optimization as an insecticidal lead with the LC50 value of 86.8 mg·L−1.
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Directional sweat-wicking by Janus fabrics has gained substantial attention in promoting personal wet-thermal management for optimal human comfort. During intense physical exercise, ...excessive sweating can cause the flooding of fabrics and weaken their wicking capabilities once the inner capillary channels are saturated. To address this issue, we develop a photothermal Janus fabric through a facile polydopamine (PDA) deposition followed by single-sided spray-coating of hydrophobic polydimethylsiloxane (PDMS). Such innovative fabrics enable directional sweat-wicking through a Janus structure and persistent removal of excessive sweat by solar-powered evaporation. Under sunlight, our photothermal Janus fabrics exhibit an enhanced evaporation rate, approximately twice compared with that of conventional Janus fabrics (∼1.143 ± 0.027 kg m-2h−1), making them suitable for high sweating rates during vigorous exercise. Furthermore, these fabrics help to maintain the skin temperature within the normal range, preventing hypothermia caused by profuse sweating. In addition, our photothermal Janus fabrics exhibit excellent washing durability even after multiple washing cycles, ensuring prolonged performance and safety.
The bimetallic 2D conductive MOFs of M1Pc–M2–O, possessing dual metal sites to realize flexible molecular-level structural modification, are brilliant catalysts for electrochemical CO2 reduction. ...However, the bimetallic centers bring about the complex regulatory mechanism of catalytic activity and obscure principles for catalyst design. Herein, systematical theoretical investigation unravels intrinsic descriptors to design favorable M1Pc–M2–O catalysts based on the discovered coarse-fine two-stage activity regulation mechanism. The reaction site controls the M–COOH distance of the key intermediate and therefore affects the reaction kinetics for the first stage of coarse regulation. The other metal site influents the d-band center of the reaction site and thus constitutes the second stage of fine regulation. The coarse and fine regulation are related to the valence electrons (V), electronegativity (E), and bond length (LM–N/O) between the metal and coordination atoms. The intrinsic descriptor φ = (4 × VM1 × (EM1 + EN/O)/EN/O + VM2 × (EM2 + EN/O)/EN/O) × LM1–N/O (with a coefficient ratio of 4 : 1) was eventually established and correlated well with the reported experiments. On this basis, the favorable catalysts CoPc–Zn–O and CoPc–Co–O were located. The research results could contribute to the diversity of bimetallic 2D c-MOFs in CO2RR.
Where did SARS-CoV-2 come from? Zhai, Shao-Lun; Wei, Wen-Kang; Lv, Dian-Hong ...
Veterinary record,
02/2020, Letnik:
186, Številka:
8
Journal Article
Recenzirano
email: zhaishaolun@163.com AT the end of 2019, a novel coronavirus (2019-nCoV) was discovered in Wuhan city, Hubei province, central China.1 Due to the close genetic relationship with severe acute ...respiratory syndrome (SARS) coronavirus (SARS-CoV), it was renamed as SARS-CoV-2 by the International Committee on Taxonomy of Viruses. Since the first case report in China, SARS-CoV-2 has, at the time of writing, also been reported in 28 other countries. During the discovery of potential intermediate hosts for SARS-CoV and MERS-CoV, multidisciplinary experts, including doctors, medical scientists, virologists, microbiologists and veterinarians, all played an important role.5, 6 Using a One Health approach, the route of the virus spread and control measures were identified, which was useful in reducing the spread of SARS-CoV and MERS-CoV. SEE PDF. SARS-CoV-2 is an emerging and zoonotic virus, and has a huge public health impact.7 At present, although SARS-CoV-2 has been found in bats and pangolins and it is likely to have spread to people, there is still much information about the virus that is unknown, including how it moves between animals and people, and whether it has other hosts.
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