Abstract
We present a study on investigating the propagation characteristics of umbral oscillations in sunspots. In sunspot 1 (located in NOAA AR 12127) with four umbrae, the analysis shows that the ...oscillations in different umbrae are correlated. The weak correlation (<20%) is attributed to the propagation of umbral oscillations across the umbral boundary to its adjacent umbra in the horizontal direction. We speculate that oscillations in two of the umbrae have a common origin in the sub-photosphere, resulting in a stronger correlation (>30%). Additionally, utilizing the TiO (photosphere), H
α
(chromosphere) images provided by BBSO/GST, and the 304 Å (upper chromosphere and lower transition region), 171 Å (upper transition region), 193 Å (corona), and 211 Å (active region corona) images acquired by the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory (SDO), we analyze the vertical propagation of oscillations in the sunspot umbra. Multi-channel observation shows that the umbral oscillations observed in the lower atmosphere of sunspot 1 cannot be detected in the upper atmosphere. However, in sunspot 2 (located in NOAA AR 12132), oscillations in the lower atmosphere can propagate to the upper atmosphere. Using photospheric magnetic field data provided by the Helioseismic and Magnetic Imager on board SDO, potential field extrapolation of the magnetic field for the two sunspots shows that open magnetic field structures allow sunspot oscillations to propagate to higher heights, while closed magnetic field structures do not.
Abstract
MicroRNAs (miRNAs) are small non-coding RNAs (typically consisting of 18–25 nucleotides) that negatively control expression of target genes at the post-transcriptional level. Owing to the ...biological significance of miRNAs, miRTarBase was developed to provide comprehensive information on experimentally validated miRNA–target interactions (MTIs). To date, the database has accumulated >13,404 validated MTIs from 11,021 articles from manual curations. In this update, a text-mining system was incorporated to enhance the recognition of MTI-related articles by adopting a scoring system. In addition, a variety of biological databases were integrated to provide information on the regulatory network of miRNAs and its expression in blood. Not only targets of miRNAs but also regulators of miRNAs are provided to users for investigating the up- and downstream regulations of miRNAs. Moreover, the number of MTIs with high-throughput experimental evidence increased remarkably (validated by CLIP-seq technology). In conclusion, these improvements promote the miRTarBase as one of the most comprehensively annotated and experimentally validated miRNA–target interaction databases. The updated version of miRTarBase is now available at http://miRTarBase.cuhk.edu.cn/.
Molecular desalination is broadly used in chemical, food, and textile industries, which needs efficient and anti‐fouling separation technologies to reach this goal. Interfacial polymerization is one ...of the most promising routes to construct ultrahigh selective nanofiltration membranes. However, the irreversible hydrolysis of residual acyl chlorides makes Donnan charges of nascent films distribute unevenly which hinders fine molecular desalination and anti‐fouling. Here, we propose a pioneering solvation‐amination‐synergy strategy to synchronously inhibit the hydrolysis of residual acyl chlorides and promote their amination. The electroneutral nanofiltration membrane with high water permeance (13.2 L m−2 h−1 bar−1) is quantitatively fabricated that has superb anti‐fouling abilities and minimizes Donnan impacts on competitive ion penetrations, so it transmits Na2SO4 and NaCl while fully obstructs cationic or anionic dyes (< 500 Da). The ultrahigh molecule to ion selectivities outperform state‐of‐art nanofiltration membranes, which may provide a paradigm shift for scalable membrane fabrication for various industrial product desalination.
Fluoroalkyl aryl ethers are valuable structural motifs in pharmaceuticals because compounds with these motifs are more metabolically stable and more lipophilic than their nonfluorinated analogues. ...However, hexafluoroisopropyl aryl ethers have not been extensively studied, presumably because of the lack of efficient synthetic methods. Herein, we describe a rhodium‐catalyzed nucleophilic aromatic substitution of aryl chlorides or bromides, which act as the limiting reagents, with weakly nucleophilic hexafluoro‐2‐propanol under mild reaction conditions. This method provides diverse hexafluoroisopropyl aryl ethers. We demonstrated the generality of this method by carrying out reactions of a large array of unactivated aryl halides, and we found that the success of the reactions relied on arene activation by means of η6‐coordination.
A rhodium catalyzed SNAr hexafluoroisopropoxylation of unactivated aryl chlorides and bromides was demonstrated. The catalyst activates the aromatic ring via η6‐coordination, dramatically facilitating the attack by weakly nucleophilic hexafluoro‐2‐propanol. Given that fluoroalkyl aryl ethers are valuable structural motifs in bioactive molecules, this method might find utility in medicinal and agricultural chemistry.
Abstract
By investigating the expression profiles of miR‐19a and metalloproteinases (
MMP13)
in human fibroblast‐like synoviocytes‐rheumatoid arthritis (HFLS‐RA) and HFL cells lines, this study ...intends to confirm the directly target connection between them and reveal the effect of suppressing
MMP13
on HLFS‐RA migration, invasion and apoptosis. After screening the abnormal expressed messenger RNAs and microRNAs in synovial tissues of patients with RA, the underlying pathway was determined by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. The HFLS‐RA cell line was transfected for the following experiments with pcDNA3.1(+) served as vector. The directly target association between miR‐19a and
MMP13
was confirmed by Luciferase reporter assay. Microarray analysis suggested that
MMP13
was upregulated while miR‐19a was downregulated in HFLS of RA tissues compared with the healthy control group.
MMP13
was related to many proteins in protein‐protein interaction network, which might be the main influencing factor of RA. KEGG pathway analysis identified that interleukin (IL)‐17 pathway was activated in the regulation of
MMP13
in the development of RA. Through observing the alteration of luciferase activity, miR‐19a could indeed bind to the 3′UTR of the downstream of
MMP13
, the target association was then confirmed. The proliferation and invasion of HFLS‐RA were promoted by overexpressing MMP13 protein. miR‐19a could function as a suppressor of
MMP13
and thereby retard the severity of RA. The results showed that miR‐19a could regulate the expression of MMP13 in HFLS‐RA by mediating the proliferation and invasion of HFLS‐RA through IL‐17 signaling pathway, thereby participating in the degradation of chondrocytes in the progression of RA.
Abstract
This paper proposes a system concept to prevent work accidents caused by vehicles transporting goods within a particular space. Furthermore, the system uses image processing methods to avoid ...these accidents. This is meant to allow the system to calculate motion vectors for all objects in the vehicle's path, so such a design can predict possible collisions. In addition to this, additional person detection has a higher priority, enabling a two-stage warning. This way, collisions endangering people can be warned earlier than collisions with other obstacles.
To develop a stable chronic obstructive pulmonary disease (COPD) model in rats. Sprague-Dawley rats were treated with cigarette-smoke inhalation (CSI) for 12 weeks, repetitive bacterial infection ...(RBI) for 8 weeks, or the combination of the two (CCR) for 12 weeks and followed up for the additional 20 weeks. Tidal volume (VT), peak expiratory flow (PEF) and 50% VT expiratory flow (EF50), histological changes in the lungs, and levels of the cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-8, and IL-10 in serum and bronchial alveolar lavage fluid (BALF) were examined at intervals during the 32 week study period. The right ventricular hypertrophy index (RVHI) was also determined at the same times. VT, PEF, and EF50 were decreased in rats with COPD compared to the control. The expression of TNF-α, IL-8 and IL-10 increased in both serum and BALF with a similar trend. Bronchiole and arteriole wall thickness and the degree of bronchiole stenosis and alveolar size increased in COPD rats. RVHI was reduced gradually following the treatment. All of these changes were more pronounced in the CCR-treatment group than in the other groups. Our results have shown that CSI or RBI alone can induce COPD in rats, but that the combination of CSI with RBI induces a stable COPD that has more similarity to complications seen in patients with COPD. This combination may therefore provide a more appropriate model for study of human COPD.
This article presents two experiments examining the effects of external focus of attention on motor performance and learning. Two main findings resulted from the present studies. First, directing ...learners' attention to the movement effect (external focus) can enhance learning complex, real-life skills. In contrast, wording instructions in a way that directs individuals' attention to coordinating their movements (internal focus), while not detrimental, is ineffective. In the present experiments, as in other studies, internal focus instructions provided no advantage compared to not giving instructions at all. Second, the benefits of adopting an external focus generalize to high skill levels. Similar to beginners, the performance of semiprofessional golfers also benefited if their attention was directed externally. (Contains 1 figure.)
In this paper, we consider a problem of recovering a space-dependent source for a time fractional diffusion wave equation by the fractional Landweber method. The inverse problem has been transformed ...into an integral equation by using the final measured data. We use the fractional Landweber regularization method for overcoming the ill-posedness. We discuss an a-priori regularization parameter choice rule and an a-posteriori regularization parameter choice rule, and we also prove the conditional stability and convergence rates for the inverse problem. Numerical experiments for four examples in one-dimensional and two-dimensional cases are provided to show the effectiveness of the proposed method.
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