47 research outputs found
Nonlinear optical properties in a quantum well with the hyperbolic confinement potential
We have performed theoretical calculation of the nonlinear optical properties
in a quantum well (QW) with the hyperbolic confinement potential. Calculation
results reveal that the transition energy, oscillator strength, second-order
nonlinear optical rectification (OR), geometric factor and nonlinear optical
absorption (OA) are strongly affected by the parameters () of
the hyperbolic confinement potential. And an increment of the parameter
reduces all these physical quantities, while an increment of the
parameter enhances them, but not for geometric factor. In addition, it
is found that one can control the optical properties of QW by tuning these
parameters.Comment: 16pages,6 figures,Accepted for publication in Physica
A longitudinal resource for population neuroscience of school-age children and adolescents in China
During the past decade, cognitive neuroscience has been calling for population diversity to address the challenge of validity and generalizability, ushering in a new era of population neuroscience. The developing Chinese Color Nest Project (devCCNP, 2013–2022), the first ten-year stage of the lifespan CCNP (2013–2032), is a two-stages project focusing on brain-mind development. The project aims to create and share a large-scale, longitudinal and multimodal dataset of typically developing children and adolescents (ages 6.0–17.9 at enrolment) in the Chinese population. The devCCNP houses not only phenotypes measured by demographic, biophysical, psychological and behavioural, cognitive, affective, and ocular-tracking assessments but also neurotypes measured with magnetic resonance imaging (MRI) of brain morphometry, resting-state function, naturalistic viewing function and diffusion structure. This Data Descriptor introduces the first data release of devCCNP including a total of 864 visits from 479 participants. Herein, we provided details of the experimental design, sampling strategies, and technical validation of the devCCNP resource. We demonstrate and discuss the potential of a multicohort longitudinal design to depict normative brain growth curves from the perspective of developmental population neuroscience. The devCCNP resource is shared as part of the “Chinese Data-sharing Warehouse for In-vivo Imaging Brain” in the Chinese Color Nest Project (CCNP) – Lifespan Brain-Mind Development Data Community (https://ccnp.scidb.cn) at the Science Data Bank
Generation of ESTs for Flowering Gene Discovery and SSR Marker Development in Upland Cotton
BACKGROUND: Upland cotton, Gossypium hirsutum L., is one of the world's most important economic crops. In the absence of the entire genomic sequence, a large number of expressed sequence tag (EST) resources of upland cotton have been generated and used in several studies. However, information about the flower development of this species is rare. METHODOLOGY/PRINCIPAL FINDINGS: To clarify the molecular mechanism of flower development in upland cotton, 22,915 high-quality ESTs were generated and assembled into 14,373 unique sequences consisting of 4,563 contigs and 9,810 singletons from a normalized and full-length cDNA library constructed from pooled RNA isolated from shoot apexes, squares, and flowers. Comparative analysis indicated that 5,352 unique sequences had no high-degree matches to the cotton public database. Functional annotation showed that several upland cotton homologs with flowering-related genes were identified in our library. The majority of these genes were specifically expressed in flowering-related tissues. Three GhSEP (G. hirsutum L. SEPALLATA) genes determining floral organ development were cloned, and quantitative real-time PCR (qRT-PCR) revealed that these genes were expressed preferentially in squares or flowers. Furthermore, 670 new putative microsatellites with flanking sequences sufficient for primer design were identified from the 645 unigenes. Twenty-five EST-simple sequence repeats were randomly selected for validation and transferability testing in 17 Gossypium species. Of these, 23 were identified as true-to-type simple sequence repeat loci and were highly transferable among Gossypium species. CONCLUSIONS/SIGNIFICANCE: A high-quality, normalized, full-length cDNA library with a total of 14,373 unique ESTs was generated to provide sequence information for gene discovery and marker development related to upland cotton flower development. These EST resources form a valuable foundation for gene expression profiling analysis, functional analysis of newly discovered genes, genetic linkage, and quantitative trait loci analysis
ATC constraints and modelling in global ATM environment
The United Kingdom’s Civil Aviation Authority published the national aviation
forecast in 2008. The forecast predicts that domestic traffic will increase by
3.5% per year, and that international traffic will grow, on average, by 4.5%
during 2010-2020. Based on this prediction, the traffic density will increase
dramatically in the future, and airspace will be more and more congested.
Usually, there are two potential solutions to deal with this situation: improving
the ability of air traffic flow management is one solution; reducing the separation
minimum of aircraft is another solution. However, this thesis focuses on the
second solution, based on constraints of communication, navigation and
surveillance systems (CNS). Cont?d
Hydrogen Peroxide Is Involved in Salicylic Acid-Elicited Rosmarinic Acid Production in Salvia miltiorrhiza Cell Cultures
Salicylic acid (SA) is an elicitor to induce the biosynthesis of secondary metabolites in plant cells. Hydrogen peroxide (H2O2) plays an important role as a key signaling molecule in response to various stimuli and is involved in the accumulation of secondary metabolites. However, the relationship between them is unclear and their synergetic functions on accumulation of secondary metabolites are unknown. In this paper, the roles of SA and H2O2 in rosmarinic acid (RA) production in Salvia miltiorrhiza cell cultures were investigated. The results showed that SA significantly enhanced H2O2 production, phenylalanine ammonia-lyase (PAL) activity, and RA accumulation. Exogenous H2O2 could also promote PAL activity and enhance RA production. If H2O2 production was inhibited by NADPH oxidase inhibitor (IMD) or scavenged by quencher (DMTU), RA accumulation would be blocked. These results indicated that H2O2 is secondary messenger for signal transduction, which can be induced by SA, significantly and promotes RA accumulation
Hydrogen Peroxide Is Involved in Salicylic Acid-Elicited Rosmarinic Acid Production in Salvia miltiorrhiza Cell Cultures
Salicylic acid (SA) is an elicitor to induce the biosynthesis of secondary metabolites in plant cells. Hydrogen peroxide (H2O2) plays an important role as a key signaling molecule in response to various stimuli and is involved in the accumulation of secondary metabolites. However, the relationship between them is unclear and their synergetic functions on accumulation of secondary metabolites are unknown. In this paper, the roles of SA and H2O2 in rosmarinic acid (RA) production in Salvia miltiorrhiza cell cultures were investigated. The results showed that SA significantly enhanced H2O2 production, phenylalanine ammonia-lyase (PAL) activity, and RA accumulation. Exogenous H2O2 could also promote PAL activity and enhance RA production. If H2O2 production was inhibited by NADPH oxidase inhibitor (IMD) or scavenged by quencher (DMTU), RA accumulation would be blocked. These results indicated that H2O2 is secondary messenger for signal transduction, which can be induced by SA, significantly and promotes RA accumulation
A meta-analysis of the response of soil moisture to experimental warming
Soil moisture is an important variable for regulating carbon, water and energy cycles of terrestrial ecosystems. However, numerous inconsistent conclusions have been reported regarding the responses of soil moisture to warming. In this study, we conducted a meta-analysis for examination of the response of soil moisture to experimental warming across global warming sites including several ecosystem types. The results showed that soil moisture decreased in response to warming treatments when compared with control treatments in most ecosystem types. The largest reduction of soil moisture was observed in forests, while intermediate reductions were observed in grassland and cropland, and they were both larger than the reductions observed in shrubland and tundra ecosystems. Increases (or no change) in soil moisture also occurred in some ecosystems. Taken together, these results showed a trend of soil drying in most ecosystems, which may have exerted profound impacts on a variety of terrestrial ecosystem processes as well as feedbacks to the climate system
Catalytic Asymmetric Synthesis of Esomeprazole by a Titanium Complex with a Hexa-aza-triphenolic Macrocycle Ligand
<div><p></p><p>An efficient synthesis of esomeprazole via catalytic asymmetric oxidation of 1<i>H</i>-benzimidazolyl pyridinylmethyl sulfide by a titanium complex with a hexa-aza-triphenolic macrocycle ligand is described. Esomeprazole was prepared with 99.6% <i>ee</i>, which meets the high requirement of the European Pharmacopeia on enantiomeric purity.</p>
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Comprehensive analyses of molecular features, prognostic values, and regulatory functionalities of m6A-modified long non-coding RNAs in lung adenocarcinoma
Abstract Background Lung adenocarcinoma (LUAD) has a high incidence and recurrence rate. N6-methyladenosine (m6A) modification of RNA has become a promising epigenetic marker in tumors. The dysregulation of both RNA m6A levels and m6A regulator expression levels reportedly affects essential biological processes in various tumors. Long non-coding RNAs (lncRNAs), a subgroup of RNAs over 200 nucleotides in length that do not code for protein, can be modified and regulated by m6A, but the relevant profile in LUAD remains unclear. Results The m6A levels of total RNA were decreased in LUAD tumor tissues and cells. Multiple m6A regulators were abnormally expressed at both the RNA and protein levels, and were related in expression patterns and functionally synergistic. Our microarray revealed 2846 m6A-modified lncRNA transcripts as well as its molecular features, 143 of which were differentially m6A-modified and manifested a negative correlation between expression levels and m6A modification levels. More than half of the differentially m6A-modified lncRNAs associated with dysregulated expression. The 6-MRlncRNA risk signature was a reliable indicator for assessing survival time of LUAD patients. The competitive endogenous regulatory network suggested a potential m6A-induced pathogenicity in LUAD. Conclusions These data have demonstrated that differential RNA m6A modification and m6A regulator expression levels were identified in LUAD patients. In addition, this study provides evidence increasing the understanding of molecular features, prognostic values, and regulatory functionalities of m6A-modified lncRNAs in LUAD