Flavonoid biosynthesis in plants is primarily regulated at the transcriptional level by transcription factors modulating the expression of genes encoding enzymes in the flavonoid pathway. One of the most studied transcription factor complexes involved in this regulation consists of a MYB, bHLH and WD40. However, in Chinese Narcissus (Narcissus tazetta L. var. chinensis), a popular monocot bulb flower, the regulatory mechanism of flavonoid biosynthesis remains unclear.In this work, genes related to the regulatory complex, NtbHLH1 and a R2R3-MYB NtMYB6, were cloned from Chinese Narcissus. Phylogenetic analysis indicated that NtbHLH1 belongs to the JAF13 clade of bHLH IIIf subgroup, while NtMYB6 was highly homologous to positive regulators of proanthocyanidin biosynthesis. Both NtbHLH1 and NtMYB6 have highest expression levels in basal plates of Narcissus, where there is an accumulation of proanthocyanidin. Ectopic over expression of NtbHLH1 in tobacco resulted in an increase in anthocyanin accumulation in flowers, and an up-regulation of expression of the endogenous tobacco bHLH AN1 and flavonoid biosynthesis genes. In contrast, the expression level of LAR gene was significantly increased in NtMYB6-transgenic tobacco. Dual luciferase assays showed that co-infiltration of NtbHLH1 and NtMYB6 significantly activated the promoter of Chinese Narcissus DFR gene. Furthermore, a yeast two-hybrid assay confirmed that NtbHLH1 interacts with NtMYB6.Our results suggest that NtbHLH1 may function as a regulatory partner by interacting directly with NtMYB6 to enhance proanthocyanidin accumulation in Chinese Narcissus.
ELABELA (ELA), previously classified as a "noncoding" RNA, is a new endogenous peptidic ligand of apelin receptor (APJ/APLNR), a class A (rhodopsin-like) G protein-coupled receptor. It has been identified to play a crucial role in diverse biological processes, especially in the normal and pathological cardiovascular system. In comparison with APJ's first ligand apelin, ELA may play a key role at different time points or heart regions. In this review, we summarized the roles of the ELA-APJ signaling pathway in cardiovascular system development and diseases.
A finite element perturbation approach to the prediction of foil bearing stiffness and damping coefficients is presented. The fluid lubricant is modeled as a simple barotropic fluid which is described by the Reynolds equation. The structural model includes membrane, bending, and elastic foundation effects in a general geometry. The equivalent viscous damping of the Coulomb friction caused by the foil relative motion is included in the structural calculation. Bearing stiffness and damping coefficients are predicted for an air-lubricated foil bearing with a corrugated sub-foil. The effects of the bearing number, bearing compliance, sub-foil Coulomb friction, and foil membrane stiffness on the bearing dynamic coefficients are discussed.
Advances have been made in identifying genetic etiologies and maternal risk factors of congenital heart defects (CHDs), while few literatures are available regarding paternal risk factors for CHDs. Thus, we aim to conduct a meta-analysis and systematic review about the non-genetic paternal risk factors for CHDs.We searched the PubMed, MEDLINE, and Cochrane Library online databases and identified 31 studies published between 1990 and 2018 according to the inclusion criteria. Paternal risk factors were divided into subgroups, and summarized odd ratios (OR) were calculated.Paternal age between 24 and 29 years decreased the risk of CHDs in the offspring (OR = 0.90 [0.82, 0.98]), while paternal age ≥ 35 years old increased the risk of CHDs (35-39 years old: OR = 1.14 [1.09, 1.19], and ≥ 40 years: OR = 1.27 [1.14, 1.42]). Paternal cigarette smoking increased the risk of CHDs in a dose-dependent way. Paternal wine drinking (OR = 1.47 [1.05, 2.07]) and exposure to chemical agents or drugs (OR = 2.15 [1.53, 3.02]) also increased the risk of CHDs. Some specific paternal occupations were also associated with increased risk for CHDs or CHD subtypes including factory workers, janitors, painters, and plywood mill workers.This meta-analysis and systematic review suggested that advanced paternal age, cigarette smoking, wine drinking, exposure to chemical agents or drugs and some specific occupations were associated with an increased risk of CHDs. More measures should be taken to reduce occupational and environment exposures. At the same time, fertility at certain age and establishment of healthy life habits are strongly recommended.
In the problem of flexible flow shop scheduling with variable processing times, the change of processing speed often affects product quality and causes fluctuations in capacity, which makes it difficult to solve the scheduling problem. In the light of the flexible flow-shop scheduling problem with variable processing times (FFSP-VPT), the FFSP-VPT mathematical model is established. The improved differential shuffled frog leaping algorithm (DSFLA) serves as the global optimisation algorithm. It overcomes the shortcomings of the adaptive shuffled frog leaping algorithm which easily falls into local optimum and converges slowly. The two-stage coding method is used to determine the online sequence of the job and processing speed of the stage with variable processing times. The simulation experiments confirm the improvement of the shuffled frog leaping algorithm in global search ability and its effectiveness in solving the flexible flow shop scheduling problem with variable processing times.
High areal density recording requires advancement in both linear density and track density. In order to resolve the side-writing issue and the edge noise reading issue associated with high track density, discrete track recording (DTR) technology was proposed by some researchers recently. While the DTR technology offers many advantages, there are difficulties yet to be overcome. With the DTR media configuration proposed by Wachenschwanz, et al. (2005), slider flyability becomes more challenging due to the land-groove structure. In addition, the discrete nature of the DTR makes the magnetic write width (MWW) narrower than its continuous counterpart (continuous track recording, CTR), resulting in lower signal amplitude. Therefore, it is the objective of this paper to evaluate the performance of DTR technology. Both tribological performance and electric performance were evaluated.
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