Polarization-sensitive and active controllable electromagnetically induced transparency in U-shaped terahertz metamaterials.

Electromagnetically induced transparency (EIT) phenomenon is observed in simple metamaterial which consists of concentric double U-shaped resonators (USRs). The numerical and theoretical analysis reveals that EIT arises from the bright-bright mode coupling. The transmission spectra at different polarization angle of incident light shows that EIT transparency window is polarization sensitive. More interestingly, Fano resonance appears in the transmission spectrum at certain polarization angles. The sharp and asymmetric Fano lineshape is high valuable for sensing. The performance of sensor is investigated and the sensitivity is high up to 327 GHz/RIU. Furthermore, active control of EIT window is realized by incorporating photosensitive silicon. The proposed USR structure is simple and compact, which may find significant applications in tunable integrated devices such as biosensor, filters, and THz modulators.

In silico analysis of novel dipeptidyl peptidase-IV inhibitory peptides released from Macadamia integrifolia antimicrobial protein 2 (MiAMP2) and the possible pathways involved in diabetes protection.

The aim of the present study was to screen novel dipeptidyl peptidase IV (DPP-IV) inhibitory peptides from Macadamia integrifolia antimicrobial protein 2 (MiAMP2) and evaluate the potential antidiabetic targets and involved signaling pathways using in silico approaches. In silico digestion of MiAMP2 with pepsin, trypsin and chymotrypsin was performed with ExPASy PeptideCutter and the generated peptides were subjected to BIOPEP-UWM, iDrug, INNOVAGEN and Autodock Vina for further analyses. Six novel peptides EQVR, EQVK, AESE, EEDNK, EECK, and EVEE were predicted to possess good DPP-IV inhibitory potentials, water solubility, and absorption, distribution, metabolism, excretion, and toxicity properties. Molecular dynamic simulation and molecular docking displayed that AESE was the most potent DPP-IV inhibitory peptide and can bind with the active sites of DPP-IV through hydrogen bonding and van der Waals forces. The potential antidiabetic targets of AESE were retrieved from SwissTargetPrediction and GeneCards databases. Protein-protein interaction analysis identified BIRC2, CASP3, MMP7 and BIRC3 to be the hub targets. Moreover, the KEGG pathway enrichment analysis showed that AESE prevented diabetes through the apoptosis and TNF signaling pathways. These results will provide new insights into utilization of MiAMP2 as functional food ingredients for the prevention and treatment of diabetes.

A genome-wide analysis reveals the MeCP2-dependent regulation of genes in BGC-823 cells.

Methyl-CpG-binding protein 2 (MeCP2) epigenetically modulates gene expression through genome-wide binding to methylated CpG dinucleotides. This study aimed to evaluate the effect of MeCP2 on the global gene expression profile of human gastric adenocarcinoma to determine the potential molecular mechanism of MeCP2. To identify the gene targets of MeCP2 in gastric cancer cells, we combined the expression microarray and chromatin immunoprecipitation approaches of MeCP2, followed by sequencing (ChIP-seq) to define the MeCP2-binding sites across the whole genome. The methylation levels of the promoters in BGC-823 cells were downloaded from the National Center for Biotechnology Information Gene Expression Omnibus database (GSM1093053). A total of 5,684 ChIP-enriched peaks were identified by comparing IP and Input, using a p-value threshold of 10-5 in ChIP-seq. The bioinformatics analysis presented a predictive model of the genome-wide MeCP2-binding pattern, in which the MeCP2 binding site is closely related to the transcription start site region in the genome. The results of motif detection showed that the MeCP2-binding regions contained not only the core CpG motif but also the extended poly (A/T) motifs. Finally, an integrative analysis of the sequence features and DNA methylation states revealed that MeCP2's function as a multifunctional transcriptional regulator may not be directly related to the methylation status of the binding site. The first MeCP2 ChIP-seq and gene expression microarray analysis in BGC-823 cells revealed that MeCP2 plays multiple roles in the regulation of gene expression depending on the microenvironment, such as sequence characteristics and the methylation levels of binding sites.

Magnetic-field sensor with self-reference characteristic based on a magnetic fluid and independent plasmonic dual resonances.

A magnetic-field sensor with self-reference characteristic based on metal-dielectric-metal (MDM) plasmonic waveguides and a magnetic fluid (MF) is proposed and theoretically investigated. Independent dual resonances are supported by the coupled resonator-waveguide system. The physical mechanisms of dual resonances are analyzed by the temporal coupled-mode theory. The transmission response to an external magnetic field is explored by using the remarkable tunability of the refractive index of the MF. Based on the different dependence of two resonances on the external field, a magnetic-field sensor with self-reference characteristic is achieved. The magnetic-field nanosensor shows an excellent performance with a high sensitivity of 27 pm/Oe, i.e., 270 pm/mT. The proposed sensor takes advantage of the refractive-index tunability of the MF and the compactness of the MDM waveguide structure. This research may open new opportunities to design nanoscale magnetic sensors with good performance.

Chia (Salvia hispanica) experiment at a 30˚ N site in Sichuan Basin, China / Performance agronômica da chia (Salvia hispanica) cultivada aos 30˚ N na Bacia de Sichuan, China

ABSTRACT: The mysterious ancient Mesoamerican Indian crop chia (Salvia hispanica) is revived and expanding worldwide due to its richness of valuable nutraceuticals such as α-linolenic acid (ALA), antioxidants, food fiber, gels, and proteins. We carried out a pilot experiment on chia planting in non-frost Sichuan Basin, at Hechuan Base (30˚0′ 43″ N, 106˚7′ 41″ E, 216 m), Southwest University, Chongqing, China. The split-plot trial contained two factors, 3 spring-summer sowing times as main plots, and 6 densities as subplots, with 3 replicates. Phenological, botanical, adversity, yield, and seed quality traits were investigated. Plants were very tall, suffered from lodging, and flowered in mid-October. Sichuan Basin can be considered as a north edge for growing chia, with low yield (680 kg/hectare) because of insufficient seed filling and maturation in autumn-winter season (1000-seed weight of 1.14 g). However, its ALA content is 5 percent points higher than the seed-donor commercial bottle (65.06%/63.96% VS 59.35%/59.74% for black/white seeds), accompanied by decrease oleic and stearic acid, while linoleic acid and palmitic acid are equivalent. Considering its short-day habit, it is recommended to try sowing in middle summer (from late June to early August) to avoid too long growing period, excessive vegetative growth, and waste of field and climate resources caused by spring-summer sowing. Furthermore, winter sowing of chia with mulch cover could also be tried, with an expectation of harvesting in summer. Most importantly, only when the photoperiod-insensitive early flowering stocks are created, chia can be recommended as a low-risk crop to the farmers of this region.

RESUMO: A chia (Salvia hispanica) é cultivada em todo o mundo por sua riqueza de nutrientes nutracêuticos valiosos, tais como a-ácido linolênico (ALA), antioxidantes, fibras alimentares, géis e proteínas. Entretanto, não há informações sobre sua performance agronômica se cultivada aos 30˚N na China. Assim, realizou-se um experimento com o cultivo de chia na base Hechuan (30°0'43"N, 106°7'41"E, 216m, que não apresenta geada) da Southwest University, Chongqing, China. O delineamento em parcela subdividida contém dois fatores,três épocas de semeadura na primavera-verão como parcelas principais e seis densidades de sementes como subparcelas, com três repetições. Foram investigados os caracteres fenológicos, botânicos, de adversidade, rendimento e qualidade da semente. As plantas se tornaram altas, acamarame floresceram em meados de outubro. A bacia de Sichuan pode ser considerada como uma fronteira limítrofe norte para o crescimento da chia, com baixo rendimento (680kg ha-1) devido ao enchimento e amadurecimento insuficientes na estação outono-inverno (peso de 1000 sementes de 1,14g). No entanto, o seu conteúdo de ALA é de 5 pontos percentuais mais elevado do que a semente comercial, 65,06%/63,96% contra 59,35%/59,74% para as sementes pretas/brancas, respectivamente, acompanhado por diminuição de ácido oleico e ácido esteárico, enquanto que o ácido linoleico e o ácido palmítico são equivalentes. Considerando o seu hábito de dia curto, recomenda-se semear no meio do verão,de junho a início de agosto, para evitar um tempo de cultivo muito longo, desenvolvimento vegetativo excessivo e desperdício de recursos de campo e clima causados pela semeadura de primavera-verão. Além disso, a semeadura de inverno da chia com cobertura morta também poderia ser realizada, com expectativa de colheita no verão. Mais importante ainda, somente quando os estoques de floração precoce insensíveis ao fotoperíodo são criados, pode-se recomendar como uma cultura de baixo risco para os agricultores desta região.