MRI in the differential diagnosis of primary architectural distortion detected by mammography

PURPOSEWe aimed to evaluate the diagnostic accuracy of a combination of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and apparent diffusion coefficient (ADC) values in lesions that manifest with architectural distortion (AD) on mammography.METHODSAll full-field digital mammography (FFDM) images obtained between August 2010 and January 2013 were reviewed retrospectively, and 57 lesions showing AD were included in the study. Two independent radiologists reviewed all mammograms and MRI data and recorded lesion characteristics according to the BI-RADS lexicon. The gold standard was histopathologic results from biopsies or surgical excisions and results of the two-year follow-up. Receiver operating characteristic curve analysis was carried out to define the most effective threshold ADC value to differentiate malignant from benign breast lesions. We investigated the sensitivity and specificity of FFDM, DCE-MRI, FFDM+DCE-MRI, and DCE-MRI+ADC.RESULTSOf the 57 lesions analyzed, 28 were malignant and 29 were benign. The most effective threshold for the normalized ADC (nADC) was 0.61 with 93.1% sensitivity and 75.0% specificity. The sensitivity and specificity of DCE-MRI combined with nADC was 92.9% and 79.3%, respectively. DCE-MRI combined with nADC showed the highest specificity and equal sensitivity compared with other modalities, independent of the presentation of calcification.CONCLUSIONDCE-MRI combined with nADC values was more reliable than mammography in differentiating the nature of disease manifesting as primary AD on mammography

A Genome-Wide Characterization of MicroRNA Genes in Maize

MicroRNAs (miRNAs) are small, non-coding RNAs that play essential roles in plant growth, development, and stress response. We conducted a genome-wide survey of maize miRNA genes, characterizing their structure, expression, and evolution. Computational approaches based on homology and secondary structure modeling identified 150 high-confidence genes within 26 miRNA families. For 25 families, expression was verified by deep-sequencing of small RNA libraries that were prepared from an assortment of maize tissues. PCR–RACE amplification of 68 miRNA transcript precursors, representing 18 families conserved across several plant species, showed that splice variation and the use of alternative transcriptional start and stop sites is common within this class of genes. Comparison of sequence variation data from diverse maize inbred lines versus teosinte accessions suggest that the mature miRNAs are under strong purifying selection while the flanking sequences evolve equivalently to other genes. Since maize is derived from an ancient tetraploid, the effect of whole-genome duplication on miRNA evolution was examined. We found that, like protein-coding genes, duplicated miRNA genes underwent extensive gene-loss, with ∼35% of ancestral sites retained as duplicate homoeologous miRNA genes. This number is higher than that observed with protein-coding genes. A search for putative miRNA targets indicated bias towards genes in regulatory and metabolic pathways. As maize is one of the principal models for plant growth and development, this study will serve as a foundation for future research into the functional roles of miRNA genes

Synthesis of Spherical Silver-coated Li4Ti5O12 Anode Material by a Sol-Gel-assisted Hydrothermal Method

Abstract ᅟ Ag-coated spherical Li4Ti5O12 composite was successfully synthesized via a sol-gel-assisted hydrothermal method using an ethylene glycol and silver nitrate mixture as the precursor, and the influence of the Ag coating contents on the electrochemical properties of its was extensively investigated. X-ray diffraction (XRD) analysis indicated that the Ag coating does not change the spinel structure of Li4Ti5O12. The electrochemical impedance spectroscopy (EIS) analyses demonstrated that the excellent electrical conductivity of the Li4Ti5O12/Ag resulted from the presence of the highly conducting silver coating layer. Additionally, the nano-thick silver layer, which was uniformly coated on the particles, significantly improved this material’s rate capability. As a consequence, the silver-coated micron-sized spherial Li4Ti5O12 exhibited excellent electrochemical performance. Thus, with an appropriate silver content of 5 wt.%, the Li4Ti5O12/Ag delivered the highest capacity of 186.34 mAh g−1 at 0.5C, which is higher than that of other samples, and maintained 92.69% of its initial capacity at 5C after 100 cycles. Even at 10C after 100 cycles, it still had a capacity retention of 89.17%, demonstrating remarkable cycling stability. Trial registration ISRCTN NARL-D-17-0056

Genetic diversity and structure of wild and cultivated Amorphophallus paeoniifolius populations in southwestern China as revealed by RAD-seq

Abstract Amorphophallus paeoniifolius, is a commercially important vegetable crop because of its high production potential. In this study, we generated a total of 166 Gb of genomic data from 16 wild and 20 cultivated A. paeoniifolius individuals in southwestern China using restriction site associated DNA sequencing (RAD-seq). We compared the genome-wide variations between the wild and cultivated populations. Wild populations exhibited higher genetic diversity than did cultivated populations based on private allele number, expected heterozygosity, observed heterozygosity and nucleotide diversity. STRUCTURE analysis, principal component analysis (PCA) and a maximum likelihood (ML) tree indicated that A. paeoniifolius populations could be divided into three groups (a cultivated group and two wild groups) with significant genetic differentiation. The low genetic diversity and shallow genetic differentiation found within cultivated populations are likely caused by continuous selection and the clonal propagation methods used during domestication. The significant differentiation between the wild populations may suggest strong genetic drift due to small populations and human disturbance. The genome-wide single nucleotide polymorphisms (SNPs) identified in our study will provide a valuable resource for further breeding improvement and effective use of the germplasm

High-Performance Cathode Material of FeF3·0.33H2O Modified with Carbon Nanotubes and Graphene for Lithium-Ion Batteries

Abstract The FeF3·0.33H2O cathode material can exhibit a high capacity and high energy density through transfer of multiple electrons in the conversion reaction and has attracted great attention from researchers. However, the low conductivity of FeF3·0.33H2O greatly restricts its application. Generally, carbon nanotubes (CNTs) and graphene can be used as conductive networks to improve the conductivities of active materials. In this work, the FeF3·0.33H2O cathode material was synthesized via a liquid-phase method, and the FeF3·0.33H2O/CNT + graphene nanocomposite was successfully fabricated by introduction of CNTs and graphene conductive networks. The electrochemical results illustrate that FeF3·0.33H2O/CNT + graphene nanocomposite delivers a high discharge capacity of 234.2 mAh g−1 in the voltage range of 1.8–4.5 V (vs. Li+/Li) at 0.1 C rate, exhibits a prominent cycling performance (193.1 mAh g−1 after 50 cycles at 0.2 C rate), and rate capability (140.4 mAh g−1 at 5 C rate). Therefore, the electronic conductivity and electrochemical performance of the FeF3·0.33H2O cathode material modified with CNTs and graphene composite conductive network can be effectively improved