Search

Multi-omics analysis of the transcriptome, metabolome and genome identified major and minor loci and candidate genes for seed coat color and explored the mechanism of flavonoid metabolites biosynthesis in Brassica rapa. Yellow seed trait is considered an agronomically desirable trait with great potential for improving seed quality of Brassica crops. Mechanisms of the yellow seed trait are complex and not well understood. In this study, we performed an integrated metabolome, transcriptome and genome-wide association study (GWAS) on different B. rapa varieties to explore the mechanisms underlying the seed coat color formation. A total of 2,499 differentially expressed genes and 116 differential metabolites between yellow and black seeds with strong association with the flavonoid biosynthesis pathway was identified. In addition, 330 hub genes involved in the seed coat color formation, and the most significantly differential flavonoids biosynthesis were detected based on weighted gene co-expression network analysis. Metabolite GWAS analysis using the contents of 42 flavonoids in developing seeds of 159 B. rapa lines resulted in the identification of 1,626 quantitative trait nucleotides (QTNs) and 37 chromosomal intervals, including one major locus on chromosome A09. A combination of QTNs detection, transcriptome and functional analyses led to the identification of 241 candidate genes that were associated with different flavonoid metabolites. The flavonoid biosynthesis pathway in B. rapa was assembled based on the identified flavonoid metabolites and candidate genes. Furthermore, BrMYB111 members (BraA09g004490.3C and BraA06g034790.3C) involved in the biosynthesis of taxifolin were functionally analyzed in vitro. Our findings lay a foundation and provide a reference for systematically investigating the mechanism of seed coat color in B. rapa and in the other plants.

High-speed railways (HSRs) greatly decrease transportation costs and facilitate the movement of goods, services, and passengers across cities. In the context of the Covid-19 pandemic, however, HSRs may contribute to the cross-regional spread of the new coronavirus. This paper evaluates the role of HSRs in spreading Covid-19 from Wuhan to other Chinese cities. We use train frequencies in 1971 and 1990 as instrumental variables. Empirical results from gravity models demonstrate that one more HSR train originating from Wuhan each day before the Wuhan lockdown increases the cumulative number of Covid-19 cases in a city by about 10 percent. The empirical analysis suggests that other transportation modes, including normal-speed trains and airline flights, also contribute to the spread of Covid-19, but their effects are smaller than the effect of HSRs. This paper's findings indicate that transportation infrastructures, especially HSR trains originating from a city where a pandemic broke out, can be important factors promoting the spread of an infectious disease.

In this study, a micro-molding technology was used to prepare the microneedles (MNs), while a texture analyzer was used to measure its Young’s modulus, Poisson’s ratio and compression breaking force, to evaluate whether the MNs can penetrate the skin. The effects of different materials were characterized by their ability to withstand stresses using the Structural Mechanics Module of COMSOL Multiphysics. Carboxymethylcellulose (CMC) was chosen as the needle formulation material with varying quantities of polyvinyl pyrrolidone (PVP), polyvinyl alcohol (PVA) and hyaluronic acid (HA) to adjust the viscosity, brittleness, hardness and solubility of the material. The results of both the experimental tests and the predictions indicated that the hardest tip material had a solids content of 15% (w/w ) with a 1:2 (w/w) CMC: HA ratio. Furthermore, it was shown that a solid content of 10% (w/w) with a 1:5 (w/w) CMC: PVA ratio is suitable for making patches. The correlation between the mechanical properties and the different materials was found using the simulation analysis as well as the force required for different dissolving microneedles (DMNs) to penetrate the skin, which significantly promoted the research progress of microneedle transdermal drug delivery.

SolidWorks and ANSYS Workbench were used to establish solid model and perform FEM analysis of truck with and without sealing covers respectively. In the past practical production, there has been no precedent for the modal analysis of the truck carriage with a sealing cover; the modal analysis is carried out for the first time in this paper. The vibration characteristics of the truck carriage are obtained. The first ten-order of non-rigid mode of the newly development truck carriage is obtained and the excitation frequency range of the idling state of the engine is calculated to avoid resonating with the ground. In order to avoid the resonance phenomenon during the truck running, the vibration characteristics of the new carriage model were studied, the first ten non-rigid modes of the new carriage model were extracted, and the excitation frequency range of the engine during idling was calculated. The non-rigid natural frequencies of the first 10 free models are between 6.18 ∼ 26.74 Hz. The engine idling excitation frequency is 32.5 ∼ 145 Hz, and the common excitation frequency caused by road roughness is 3 Hz. In theory, it does not cause resonance when driving in a normal state.

The allotetraploid species Brassica juncea (mustard) is grown worldwide as oilseed and vegetable crops, the yellow seed-color trait is particularly important for oilseed crops. Here, to examine the factors affecting seed coat color, we performed a metabolic and transcriptomic analysis of yellow- and dark-seeded B. juncea seeds. In this study, we identified 236 compounds, including 31 phenolic acids, 47 flavonoids, 17 glucosinolates, 38 lipids, 69 other hydroxycinnamic acid compounds, and 34 novel unknown compounds. Of these, 36 compounds (especially epicatechin and its derivatives) accumulated significantly different levels during the development of yellow- and dark-seeded B. juncea. In addition, the transcript levels of BjuDFR, BjuANS,BjuBAN, BjuTT8, and BjuTT19 were closely associated with changes to epicatechin and its derivatives during seed development, implicating this pathway in the seed coat color determinant in B. juncea. Furthermore, we found numerous variations of sequences in the TT8A genes that may be associated with the stability of seed coat color in B. rapa, B. napus, and B. juncea, which might have undergone functional differentiation during polyploidization in the Brassica species. The results provide valuable information for understanding the accumulation of metabolites in the seed coat color of B. juncea and lay a foundation for exploring the underlying mechanism.

Cobalt (II, III) oxide (Co

The AINTEGUMENTA-like (AIL) proteins, which belong to the AP2 family, play important roles in regulating the growth and development of plant organs. The AIL family has not yet been comprehensively studied in rapeseed (Brassica napus), an allotetraploid and model organism for the study of polyploid evolution. In the present study, 99 AIL family genes were identified and characterized from B. rapa, B. oleracea, B. napus, B. juncea, and B. nigra using a comprehensive genome-wide study, including analyses of phylogeny, gene structure, chromosomal localization, and expression pattern. Using a phylogenetic analysis, the AIL genes were divided into eight groups, which were closely related to the eight AtAIL genes, and which shared highly conserved structural features within the same subfamily. The non-synonymous/synonymous substitution ratios of the paralogs and orthologs were less than 1, suggesting that the AIL genes mainly experienced purifying selection during evolution. In addition, the RNA sequencing data and qRT-PCR analysis revealed that the B. napus AIL genes exhibited organ- and developmental stage-specific expression patterns. Certain genes were highly expressed in the developing seeds (BnaAIL1, BnaAIL2, BnaAIL5, and BnaAIL6), the roots (BnaANT, BnaAIL5, and BnaAIL6), and the stem (BnaAIL7B). Our results provide valuable information for further functional analysis of the AIL family in B. napus and related Brassica species.

Phosphorus transporter (PHT) genes encode H2PO4&minus, /H+ co-transporters that absorb and transport inorganic nutrient elements required for plant development and growth and protect plants from heavy metal stress. However, little is known about the roles of PHTs in Brassica compared to Arabidopsis thaliana. In this study, we identified and extensively analyzed 336 PHTs from three diploid (B. rapa, B. oleracea, and B. nigra) and two allotetraploid (B. juncea and B. napus) Brassica species. We categorized the PHTs into five phylogenetic clusters (PHT1&ndash, PHT5), including 201 PHT1 homologs, 15 PHT2 homologs, 40 PHT3 homologs, 54 PHT4 homologs, and 26 PHT5 homologs, which are unevenly distributed on the corresponding chromosomes of the five Brassica species. All PHT family genes from Brassica are more closely related to Arabidopsis PHTs in the same vs. other clusters, suggesting they are highly conserved and have similar functions. Duplication and synteny analysis revealed that segmental and tandem duplications led to the expansion of the PHT gene family during the process of polyploidization and that members of this family have undergone purifying selection during evolution based on Ka/Ks values. Finally, we explored the expression profiles of BnaPHT family genes in specific tissues, at various developmental stages, and under heavy metal stress via RNA-seq analysis and qRT-PCR. BnaPHTs that were induced by heavy metal treatment might mediate the response of rapeseed to this important stress. This study represents the first genome-wide analysis of PHT family genes in Brassica species. Our findings improve our understanding of PHT family genes and provide a basis for further studies of BnaPHTs in plant tolerance to heavy metal stress.

Summary Brady (Journal of Applied Econometrics, 2011, 26(2), 213–231) studies how fast and how long a change in housing prices in one region affects its neighbors by estimating the impulse response functions using a spatial autoregressive model (SAR). This paper replicates Brady's empirical results, but reports different SAR test statistics. Additional robustness checks are conducted by analyzing three different housing price indexes covering a more extensive period. Analysis shows that the model specifications and model estimates vary with the housing price indexes.

Phosphorus transporter (PHT) genes encode H2PO4−/H+ co-transporters that absorb and transport inorganic nutrient elements required for plant development and growth and protect plants from heavy metal stress. However, little is known about the roles of PHTs in Brassica compared to Arabidopsis thaliana. In this study, we identified and extensively analyzed 336 PHTs from three diploid (B. rapa, B. oleracea, and B. nigra) and two allotetraploid (B. juncea and B. napus) Brassica species. We categorized the PHTs into five phylogenetic clusters (PHT1–PHT5), including 201 PHT1 homologs, 15 PHT2 homologs, 40 PHT3 homologs, 54 PHT4 homologs, and 26 PHT5 homologs, which are unevenly distributed on the corresponding chromosomes of the five Brassica species. All PHT family genes from Brassica are more closely related to Arabidopsis PHTs in the same vs. other clusters, suggesting they are highly conserved and have similar functions. Duplication and synteny analysis revealed that segmental and tandem duplications led to the expansion of the PHT gene family during the process of polyploidization and that members of this family have undergone purifying selection during evolution based on Ka/Ks values. Finally, we explored the expression profiles of BnaPHT family genes in specific tissues, at various developmental stages, and under heavy metal stress via RNA-seq analysis and qRT-PCR. BnaPHTs that were induced by heavy metal treatment might mediate the response of rapeseed to this important stress. This study represents the first genome-wide analysis of PHT family genes in Brassica species. Our findings improve our understanding of PHT family genes and provide a basis for further studies of BnaPHTs in plant tolerance to heavy metal stress.

The high levels of secondary metabolites in rapeseed play important roles in determining the oil quality and feeding value. Here, we characterized the metabolic profiles in seeds of various yellow- and black-seeded rapeseed accessions. Two hundred and forty-eight features were characterized, including 31 phenolic acids, 54 flavonoids, 24 glucosinolates, 65 lipid compounds, and 74 other polar compounds. The most abundant phenolic acids and various flavonoids (epicatechin, isorhamnetin, kaempferol, quercetin, and their derivatives) were widely detected and showed significant differences in distribution between the yellow- and black-seeded rapeseed. Furthermore, the related genes (e.g., BnTT3, BnTT18, BnTT10, BnTT12, and BnBAN) involved in the proanthocyanidin pathway had lower expression levels in yellow-seeded rapeseed, strongly suggesting that the seed coat color could be mainly determined by the levels of epicatechin and their derivatives. These results improve our understanding of the primary constituents of rapeseed and lay the foundation for breeding novel varieties with a high nutritional value.

Tin oxide/reduced graphene oxide (SnO2/rGO) composite was extensively used in the area lithium ion batteries, solar cells, sensors and catalysts. High loading of SnO2 was effective for improving the performance, however, which inevitably led to large clusters of SnO2 and the active sites would decrease accordingly. Herein, crumpled SnO2/rGO with concentrated sites was prepared by spray pyrolysis, the density of SnO2 crystals was increased without agglomeration. The ultrafine SnO2 nanocrystals with the size of 3.5 nm interconnected with each other to form an intensive 2D web, which compounded with rGO nanosheets by Sn–O–C covalent bonds, and the SnO2/rGO nanosheets assembled to form a 3D crumpled ball-like structure. The crumpled 2D-in-3D structure and the Sn–O–C bonds endowed the SnO2/rGO with excellent dispersion, good electrical conductivity and structural stability, increased active sites and multilevel mass transfer channels, therefore, SnO2/rGO demonstrated good electrochemical and catalytic performance. The capacity and coulombic efficiency of Sn-1-550 as anode material of lithium battery were 943 mA h g−1 and 94% after 80 cycles, and methyl blue (MB) was catalytic degraded completely by Sn-1-550 in 15 min at room temperature.

The investigation of the interacting proteins with testis-specific calcium-binding protein CBP86-IV (CABYR) was carried out in human spermatozoa. The total RNA from human spermatozoa was extracted, and the ORF sequence of TSCBP86-IV gene was amplified and cloned into expression vector pET-28a. The positive recombinant clones were transformed into Escherichia coli strain BL21 (DE3) to express fusion protein. Then, co-immunoprecipitation (Co-IP) of TSCBP86-IV was performed in BL21 cell lysate expressing CBP86-IV recombinant protein. The immune complex was captured and identified by mass spectrometry. Reverse Co-IP of potential interacting proteins was performed in human sperm cell lysate. The potential protein interactions were confirmed by yeast two-hybrid system. Thirteen proteins were successfully identified in immune complex from E. coli cell lysate. Phosphoglycerate kinase 2 (PGK2) further showed positive results both in reverse Co-IP and yeast two-hybrid experiments and was confirmed to be interacted with TSCBP86-IV in human sperm cells.

Cisplatin (CDDP) is one of the most effective anticancer agents widely used in the treatment of solid tumors, including ovarian cancer. It is generally considered as a cytotoxic drug which kills cancer cells by causing DNA damage, and subsequently inducing apoptosis in cancer cells. However, the underlying mechanisms leading to cell apoptosis remain obscure. In this study, the signaling pathways involved in CDDP-induced apoptosis were examined using CDDP-sensitive ovarian cancer A2780s cells. A2780s cells were treated with CDDP (1.5-3 μg/ml) for 6h, 12h and 24h. Using siRNA targeting P53 and PUMA, and a selective MEK inhibitor, PD98059 to examine the relation between ERK1/2 activation, p53 and PUMA expression after exposure to CDDP, and the effect on CDDP-induced apoptosis. The results shown that treatment of A2780s cells with CDDP (3 μg/ml) for 6-24h induced apoptosis, resulting in the activation of extracellular signal-regulated kinase 1/2 (ERK1/2) and accumulation of p53 and PUMA (p53 upregulated modulator of apoptosis) protein. Knockdown of P53 or PUMA by siRNA transfection blocked CDDP-induced apoptosis. Inhibition of ERK1/2 using PD98059, a selective MEK inhibitor, blocked the apoptotic cell death but prevented CDDP-induced accumulation of p53 and PUMA. Knockdown of P53 by siRNA transfection also blocked CDDP-induced accumulation of PUMA. We therefore concluded that CDDP activated ERK1/2 and induced-p53-dependent PUMA upregulation, resulting in triggering apoptosis in A2780s cells. Our study clearly demonstrates that the ERK1/2/p53/PUMA axis is related to CDDP-induced cell death in A2780s cells.

To investigate the expression level of testis-specific calcium-binding protein CBP86-IV in normal and asthenozoospermic human sperm. The total RNA was extracted from human sperm, and target cDNA was obtained by reverse transcription–polymerase chain reaction. Then the cDNA was used for quantitative PCR analysis and cloned into the prokaryotic expression vector pET-28a, respectively. The fusion protein was induced and expressed as inclusion body which was used to produce the polyclonal antibody against TSCBP86-IV. The protein expression level of TSCBP86-IV from normal human sperm and idiopathic asthenozoospermic samples was detected by the purified antibody. The experimental results showed that the protein expression of TSCBP86-IV was reduced in idiopathic asthenozoospermia and consistent with the transcriptional changing tendency which was detected by quantitative PCR analysis. The stable and reliable change of TSCBP86-IV may be taken as a new molecular marker for clinical diagnosis of idiopathic asthenozoospermia.

Demand-side Management (DSM) based on the Smart Grid directing to various electrical appliances in the household will contribute to improved demand-side response and cost-effective policy. Evaluating the use value of different electrical end uses and analyzing associated characteristics of population in the household side will provide basic information for the Integrated Resource Planning (IRP). This paper takes the residential air-conditioner as an example, and applies the Contingent Valuation Method (CVM) to investigate its use value during summer peak load in Xi'an City, China. Four controlling scenarios are considered. The study reveals that the value is quite different among the surveyed population, and a large proportion of people are ready to accept control with a small amounts of compensation. These people have a series of characteristics such as high level of education, energy-saving, and so on.

Idiopathic asthenozoospermia is considered as one of the causes of male infertility and characterized by reduced sperm motility. For a better determination of pathogenic mechanism of asthenozoospermia, the exploration of differentially expressed proteins in normal sperm motility and idiopathic asthenozoospermia was conducted in our study.Sperm proteins were extracted and isolated by two-dimensional electrophoresis. All significantly changed protein spots were picked up from 2D gels and identified by tandem mass spectrometry. Sixteen of the thirty-three total differentially expressed protein spots were successfully identified by matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry.Sixteen proteins identified belonged to 15 unique protein groups. GRP78, lactoferrin, SPANXB, PGK2, flagellin, DJ-1, XPA binding protein 2, CAB2, GPX4, and GAPDH were the first to be identified as differentially expressed proteins in idiopathic asthenospermia patients. Meanwhile, the analysis of quantitative RT-PCR was carried out to compare the protein levels, and the results indicated that the expression levels of the gene and protein were not entirely consistent.These experimental results expand the scope of the protein database, generating targets for further investigation of the pathogenic mechanism of idiopathic asthenozoospermia.