Substoichiometrically Different Mitotypes Coexist in Mitochondrial Genomes of Brassica napus L

Cytoplasmic male sterility (CMS) has been identified in numerous plant species. Brassica napus CMS plants, such as Polima (pol), MI, and Shaan 2A, have been identified independently by different researchers with different materials in conventional breeding processes. How this kind of CMS emerges is unclear. Here, we report the mitochondrial genome sequence of the prevalent mitotype in the most widely used pol-CMS line, which has a length of 223,412 bp and encodes 34 proteins, 3 ribosomal RNAs, and 18 tRNAs, including two near identical copies of trnH. Of these 55 genes, 48 were found to be identical to their equivalents in the “nap” cytoplasm. The nap mitotype carries only one copy of trnH, and the sequences of five of the six remaining genes are highly similar to their equivalents in the pol mitotype. Forty-four open reading frames (ORFs) with unknown function were detected, including two unique to the pol mitotype (orf122 and orf132). At least five rearrangement events are required to account for the structural differences between the pol and nap sequences. The CMS-related orf224 neighboring region (∼5 kb) rearranged twice. PCR profiling based on mitotype-specific primer pairs showed that both mitotypes are present in B. napus cultivars. Quantitative PCR showed that the pol cytoplasm consists mainly of the pol mitotype, and the nap mitotype is the main genome of nap cytoplasm. Large variation in the copy number ratio of mitotypes was found, even among cultivars sharing the same cytoplasm. The coexistence of mitochondrial mitotypes and substoichiometric shifting can explain the emergence of CMS in B. napus

Engineering Plasmonic Environments for 2D Materials and 2D-Based Photodetectors

Two-dimensional layered materials are considered ideal platforms to study novel small-scale optoelectronic devices due to their unique electronic structures and fantastic physical properties. However, it is urgent to further improve the light–matter interaction in these materials because their light absorption efficiency is limited by the atomically thin thickness. One of the promising approaches is to engineer the plasmonic environment around 2D materials for modulating light–matter interaction in 2D materials. This method greatly benefits from the advances in the development of nanofabrication and out-plane van der Waals interaction of 2D materials. In this paper, we review a series of recent works on 2D materials integrated with plasmonic environments, including the plasmonic-enhanced photoluminescence quantum yield, strong coupling between plasmons and excitons, nonlinear optics in plasmonic nanocavities, manipulation of chiral optical signals in hybrid nanostructures, and the improvement of the performance of optoelectronic devices based on composite systems

Effect of Alkali Pollutant in Influencing Crack Propagation in Soils

Shrinkage, deformation, and cracking will occur under extreme climate conditions such as drought, due to the accumulation of salt inside the soil during the evaporation of water on the surface of the soil. In this study, the image processing method was used to quantitatively analyze the dehydration cracking process of clay polluted by alkaline pollutant sodium carbonate on the basis of experiments. The mechanism of the effect of sodium carbonate concentration on the shrinkage cracks of clay was discussed through the analysis and comparison of different concentrations of sodium carbonate samples. The results showed that the water loss and shrinkage cracks of alkaline contaminant clay were developed in different stages. Firstly, first-level cracks developed diagonally or parallel to the edge of the container, and then second-level cracks developed along the main cracks with an angle of close to 90°. Most of the third-level or higher-level cracks were approximately perpendicular to the second-level cracks or the edge of the container and developed in parallel. In the cracking stage, the water loss ratio of the sample had a good positive correlation with the surface crack ratio. The slope of the fitted curve increased with the increase of the sodium carbonate concentration. With the increase of sodium carbonate concentration, the water loss ratio and the width of first-level cracks of clayey soil decreased, and the total length and the number of cracks increased, while the surface cracking ratio increased first and then decreased

Organic-inorganic manganese (II) halide hybrids based paper sensor for the fluorometric determination of pesticide ferbam

Organic-inorganic metal halide hybrids, which consist of metal halide anions and organic cations, have been widely applied in the sensor design. Instead of general lead (high toxicity) and copper (I) (weak stability) halide hybrids, the low toxic and highly luminescent manganese (II) halide hybrids may be more promising for optical sensors. In this work, a paper sensor based on the organic-inorganic manganese (II) halide hybrids is fabricated as the first attempt. Three new highly luminescent and soluble manganese (II) halide hybrids MnBr4 (TPA)(2), MnBr4(TEA)(2) and MnCl4 (btmdme)(2) are prepared, and their quantum yields are 89.23%, 78.86% and 71.28%, respectively. The hybrids are dispersed uniformly and immoblized on the wax-based paper. The as-fabricated sensor is used for the fluorometric determination of pesticide ferbam, and the limit of detection is calculated to be 0.06 ppm, which is even lower than the maximum permissible concentration in EU pesticides database. Moreover, the practical application of ferbam assay for apple and pear samples is described with satisfactory recoveries (91.88-101.32%). The mechanism of ferbam detection is investigated in detail, and tentatively explained by the interaction between the manganese in MnBr4(TPA)(2) and the sulfur in ferbam together with the inner filter effect (IFE)

Complete mitochondrial genome of Eruca sativa Mill. (Garden rocket).

Eruca sativa (Cruciferae family) is an ancient crop of great economic and agronomic importance. Here, the complete mitochondrial genome of Eruca sativa was sequenced and annotated. The circular molecule is 247,696 bp long, with a G+C content of 45.07%, containing 33 protein-coding genes, three rRNA genes, and 18 tRNA genes. The Eruca sativa mitochondrial genome may be divided into six master circles and four subgenomic molecules via three pairwise large repeats, resulting in a more dynamic structure of the Eruca sativa mtDNA compared with other cruciferous mitotypes. Comparison with the Brassica napus MtDNA revealed that most of the genes with known function are conserved between these two mitotypes except for the ccmFN2 and rrn18 genes, and 27 point mutations were scattered in the 14 protein-coding genes. Evolutionary relationships analysis suggested that Eruca sativa is more closely related to the Brassica species and to Raphanus sativus than to Arabidopsis thaliana

Performance analysis of a novel trench SOI LDMOS with centrosymmetric double vertical field plates

A novel trench SOI LDMOS with centrosymmetric double vertical field plates structure (CDVFPT SOI LDMOS) is proposed in this paper. The 2-D device simulator MEDICI is used to investigate the characteristics of the proposed structure. Compared with the conventional trench SOI LDMOS (CT SOI LDMOS), the optimized device shows an obvious reduction in the specific on-resistance (Ron,sp) when its breakdown voltage (BV) is enhanced due to the introduction of centrosymmetric double vertical field plates structure. And when compared to previous device with floating vertical field plate trench SOI LDMOS (FVFPT SOI LDMOS), the overall performance of CDVFPT SOI LDMOS is also promoted. According to the simulation results, compared to a CT SOI LDMOS, the BV of CDVFPT SOI LDMOS increases from 188 V to 234 V. The Ron,sp, however, decreases from 2.30 mΩ·cm2 to 1.24 mΩ·cm2. In addition, the maximum lattice temperature at 1 mW/μm2 is slightly reduced. Keywords: Power MOSFET, Vertical field plate, Breakdown voltage, Specific on-resistanc

Molecular length adjustment for organic azo-based nonvolatile ternary memory devices

Two conjugated small molecules with different molecular length, DPAPIT and DPAPPD, in which an electron donor dimethylamino moiety and an electron acceptor phthalimide core unit are bridged by another electron-accepting azobenzene block, were designed and synthesized. DPAPIT molecule with longer conjugation length stacked regularly in the solid state and formed uniform nanocrystalline film. The fabricated memory devices with DPAPIT as active material exhibited outstanding nonvolatile ternary memory effect with the current ratio of 1:101.7:104 for “0”, “1” and “2” states and all the switching threshold voltages lower than −3 V. In contrast, the shorter molecule DPAPPD showed amorphous microstructure and no obvious conductive switching behavior was observed in the device. The crystallinity and surface roughness of DPAPIT thin films were significantly improved as the annealing temperature increased, lowering the switching threshold voltages which are highly desirable for low-power consumption data-storage devices. It is worth noting that the tristable memory signals of DPAPIT film could also be achieved by using conductive atomic force microscopy with platinum-coated probe, which enables fabrication of nano-scale or even molecular-scale device, a significant progress for the ultra-high density data storage application. Mechanism analysis demonstrated that two charge traps with different depth in the molecular backbone were injected by charge carriers progressively as the external bias increased, resulting in the formation of three distinct conductive states (OFF, ON1 and ON2 states)