Search Results (19)

Background: Only a few studies have reported on chlorinated paraffin (CP) levels, especially long-chain chlorinated paraffins (LCCPs), in submicron particulate matter (PM₁) in the outdoor air around primary and secondary schools. Methods: This study examined concentrations of short-chain CPs (SCCPs), medium-chain CPs (MCCPs), and LCCPs in PM₁ samples from 96 schools across six cities in China’s Pearl River Delta region during the winter (October to December 2018). Results: The median total CP concentration was 34 ng/m³, with median values for SCCP, MCCP, and LCCP of 17.3, 15, and 0.7 ng/m³, respectively. The primary congeners were C₁₃Cl_6–8 for SCCPs, C₁₄Cl_6–9 for MCCPs, and C₁₈Cl_7–10 for LCCPs. The SCCPs and MCCPs largely originated from fugitive dust, whereas the LCCPs were mainly sourced from organic chemical industries. Air masses from the South China Sea contributed most to SCCP and MCCP levels, while those from the east coast accounted for the highest LCCP levels. The concentrations of CP in PM₁ were significantly positively correlated with PM₁ levels. Conclusions: The exposure risk assessments by age indicated a very low current health risk from PM₁-related CP inhalation, although prolonged pollution could raise these risks as CP concentrations in ambient PM may continue to increase. Full article

Dragon fruit comprises a wide variety of species that are rich in nutritional value and have great economic potential; however, numerous studies have focused on their nutritional and commercial quality. In contrast, few studies have addressed their flavor quality, particularly with respect to the regulatory networks responsible for their flavor-related substance contents. To this end, we sequenced the transcriptomes and metabolomes of red-skin/white-fleshed and red-skin/red-fleshed dragon fruit at different timepoints during fruit development. RNA-seq and metabolome data were used to divide the seven developmental stages of the dragon fruit into four categories (young fruit, expansion, maturity, and senescence). In all, 16,827 differentially expressed genes (DEGs), including 958 transcription factors, were identified and grouped into 10 clusters, and the pathways in each cluster were annotated. Additionally, 318 differentially accumulated metabolites (DAMs) were identified, including 88 common metabolites. The main flavor-related substances and the key genes regulating them were determined via joint analysis via RNA-seq and metabolomics. Furthermore, 10 volatile active components related to green flavors and aromas were screened according to the relative odor activity value (ROAV), and 15 candidate genes related to key flavor compounds were screened via WGCNA, 3 of which encoded transcription factors. In conclusion, our results provide a theoretical basis for an in-depth understanding of the volatile flavor compounds in dragon fruit and provide new genetic resources for the subsequent study of fruit flavor compounds. Full article

Salinization of freshwater ecosystems is a pressing global issue. Changes in salinity can exert severe pressure on aquatic animals and jeopardize their survival. Procambarus clarkii is a valuable freshwater aquaculture species that exhibits some degree of salinity tolerance, making it an excellent research model for freshwater aquaculture species facing salinity stress. In the present study, crayfish were exposed to acute low salt (6 ppt) and high salt (18 ppt) conditions. The organisms were continuously monitored at 6, 24, and 72 h using RNA-Seq to investigate the mechanisms of salt stress resistance. Transcriptome analysis revealed that the crayfish responded to salinity stress with numerous differentially expressed genes, and most of different expression genes was observed in high salinity group for 24h. GO and KEGG enrichment analyses indicated that metabolic pathways were the primary response pathways in crayfish under salinity stress. This suggests that crayfish may use metabolic pathways to compensate for energy loss caused by osmotic stress. Furthermore, gene expression analysis revealed the differential expression of immune and antioxidant-related pathway genes under salinity stress, implying that salinity stress induces immune disorders in crayfish. More genes related to cell proliferation, differentiation, and apoptosis, such as the Foxo, Wnt, Hippo, and Notch signaling pathways, responded to high-salinity stress. This suggests that regulating the cellular replication cycle and accelerating apoptosis may be necessary for crayfish to cope with high-salinity stress. Additionally, we identified 36 solute carrier family (SLC) genes related to ion transport, depicting possible ion exchange mechanisms in crayfish under salinity stress. These findings aimed to establish a foundation for understanding crustacean responses to salinity stress and their osmoregulatory mechanisms. Full article

An exploration of the plasma-sprayed abradable sealing coatings (ASCs) of a thick and porous LaMgAl₁₁O₁₉ topcoat onto SiC/SiC ceramic matrix composites (CMCs) is detailed in this study. Interlayers comprising Si/Si + Yb₂Si₂O₇/Yb₂SiO₅ environmental barrier coatings (EBCs) were strategically employed, considering their function in protecting the SiC/SiC CMCs from recession and mitigating thermal expansivity misfit. An isothermal oxidation test was conducted at 1300 °C and resulted in the formation of bubble and glassy melt on the side surface of the coated sample, while a significant reaction layer emerged at the Yb₂SiO₅/LaMgAl₁₁O₁₉ interface near the edge. The localized temperature rise caused by the exothermic oxidation of the SiC/SiC substrate was determined to be the underlying factor for bubble generation. The temperature-dependent viscosity of the melt contributed to various bubble characteristics, and due to the enrichment of Al ions, the glassy melt exacerbated the degradation of the Yb₂SiO₅ layer. After a thermal shock test at 1300 °C, the substrate on the uncoated backside of the sample experienced fracture, while the front coating remained intact. However, due to the presence of a through-coating crack, an internal crack network also developed within the substrate. Full article

WUSCHEL-related homeobox (WOX) is a plant-specific transcription factor (TF), which plays an essential role in the regulation of plant growth, development, and abiotic stress responses. However, little information is available on the specific roles of WOX TFs in sacred lotus (Nelumbo nucifera), which is a perennial aquatic plant with important edible, ornamental, and medicinal values. We identified 15 WOX TFs distributing on six chromosomes in the genome of N. nucifera. A total of 72 WOX genes from five species were divided into three clades and nine subclades based on the phylogenetic tree. NnWOXs in the same subclades had similar gene structures and conserved motifs. Cis-acting element analysis of the promoter regions of NnWOXs found many elements enriched in hormone induction, stress responses, and light responses, indicating their roles in growth and development. The Ka/Ks analysis showed that the WOX gene family had been intensely purified and selected in N. nucifera. The expression pattern analysis suggested that NnWOXs were involved in organ development and differentiation of N. nucifera. Furthermore, the protein–protein interaction analysis showed that NnWOXs might participate in the growth, development, and metabolic regulation of N. nucifera. Taken together, these findings laid a foundation for further analysis of NnWOX functions. Full article

Marine toxins (MTs) are a group of structurally complex natural products with unique toxicological and pharmacological activities. In the present study, two common shellfish toxins, okadaic acid (OA) (1) and OA methyl ester (2), were isolated from the cultured microalgae strain Prorocentrum lima PL11. OA can significantly activate the latent HIV but has severe toxicity. To obtain more tolerable and potent latency reversing agents (LRAs), we conducted the structural modification of OA by esterification, yielding one known compound (3) and four new derivatives (4–7). Flow cytometry-based HIV latency reversal activity screening showed that compound 7 possessed a stronger activity (EC₅₀ = 46 ± 13.5 nM) but was less cytotoxic than OA. The preliminary structure–activity relationships (SARs) indicated that the carboxyl group in OA was essential for activity, while the esterification of carboxyl or free hydroxyls were beneficial for reducing cytotoxicity. A mechanistic study revealed that compound 7 promotes the dissociation of P-TEFb from the 7SK snRNP complex to reactivate latent HIV-1. Our study provides significant clues for OA-based HIV LRA discovery. Full article

The YABBY gene family plays an important role in plant growth and development, such as response to abiotic stress and lateral organ development. YABBY TFs are well studied in numerous plant species, but no study has performed a genome-wide investigation of the YABBY gene family in Melastoma dodecandrum. Therefore, a genome-wide comparative analysis of the YABBY gene family was performed to study their sequence structures, cis-acting elements, phylogenetics, expression, chromosome locations, collinearity analysis, protein interaction, and subcellular localization analysis. A total of nine YABBY genes were found, and they were further divided into four subgroups based on the phylogenetic tree. The genes in the same clade of phylogenetic tree had the same structure. The cis-element analysis showed that MdYABBY genes were involved in various biological processes, such as cell cycle regulation, meristem expression, responses to low temperature, and hormone signaling. MdYABBYs were unevenly distributed on chromosomes. The transcriptomic data and real-time reverse transcription quantitative PCR (RT-qPCR) expression pattern analyses showed that MdYABBY genes were involved in organ development and differentiation of M. dodecandrum, and some MdYABBYs in the subfamily may have function differentiation. The RT-qPCR analysis showed high expression of flower bud and medium flower. Moreover, all MdYABBYs were localized in the nucleus. Therefore, this study provides a theoretical basis for the functional analysis of YABBY genes in M. dodecandrum. Full article

(1) Background: DNA double strand breaks (DSBs) are the most serious form of DNA damage that affects oocyte maturation and the physiological state of follicles and ovaries. Non-coding RNAs (ncRNAs) play a crucial role in DNA damage and repair. This study aims to analyze and establish the network of ncRNAs when DSB occurs and provide new ideas for next research on the mechanism of cumulus DSB. (2) Methods: Bovine cumulus cells (CCs) were treated with bleomycin (BLM) to construct a DSB model. We detected the changes of the cell cycle, cell viability, and apoptosis to determine the effect of DSBs on cell biology, and further evaluated the relationship between the transcriptome and competitive endogenous RNA (ceRNA) network and DSBs. (3) Results: BLM increased γH2AX positivity in CCs, disrupted the G1/S phase, and decreased cell viability. Totals of 848 mRNAs, 75 long noncoding RNAs (lncRNAs), 68 circular RNAs (circRNAs), and 71 microRNAs (miRNAs) in 78 groups of lncRNA–miRNA–mRNA regulatory networks, 275 groups of circRNA–miRNA–mRNA regulatory networks, and five groups of lncRNA/circRNA–miRNA–mRNA co-expression regulatory networks were related to DSBs. Most differentially expressed ncRNAs were annotated to cell cycle, p53, PI3K-AKT, and WNT signaling pathways. (4) Conclusions: The ceRNA network helps to understand the effects of DNA DSBs activation and remission on the biological function of CCs. Full article

Growth-regulating factor (GRF) is a kind of transcription factor unique to plants, playing an important role in the flowering regulation, growth, and development of plants. Melastoma dodecandrum is an important member of Melastomataceae, with ornamental, medicinal, and edible benefits. The identification of the GRF gene family in M. dodecandrum can help to improve their character of flavor and continuous flowering. The members of the GRF gene family were identified from the M. dodecandrum genome, and their bioinformatics, selective pressure, and expression patterns were analyzed. The results showed that there were 20 GRF genes in M. dodecandrum. Phylogenetic analysis showed that the 71 GRF genes from M. dodecandrum, Arabidopsis thaliana, Camellia sinensis, and Oryza sativa can be divided into three clades and six subclades. The 20 GRF genes of M. dodecandrum were distributed in twelve chromosomes and one contig. Furthermore, the gene structure and motif analysis showed that the intron and motif within each clade were very similar, but there were great differences among different clades. The promoter contained cis-acting elements related to hormone induction, stress, and growth and development. Different transcriptomic expression of MdGRFs indicated that MdGRFs may be involved in regulating the growth and development of M. dodecandrum. The results laid a foundation for further study on the function and molecular mechanism of the M. dodecandrum GRF gene family. Full article

Doublesex (Dsx) is a polymorphic transcription factor of the DMRTs family, which is involved in male sex trait development and controls sexual dimorphism at different developmental stages in arthropods. However, the transcriptional regulation of the Dsx gene is largely unknown in decapods. In this study, we reported the cDNA sequence of PmDsx in Penaeus monodon, which encodes a 257 amino acid polypeptide. It shared many similarities with Dsx homologs and has a close relationship in the phylogeny of different species. We demonstrated that the expression of the male sex differentiation gene Dsx was predominantly expressed in the P. monodon testis, and that PmDsx dsRNA injection significantly decreased the expression of the insulin-like androgenic gland hormone (IAG) and male sex-determining gene while increasing the expression of the female sex-determining gene. We also identified a 5′-flanking region of PmIAG that had two potential cis-regulatory elements (CREs) for the PmDsx transcription. Further, the dual-luciferase reporter analysis and truncated mutagenesis revealed that PmDsx overexpression significantly promoted the transcriptional activity of the PmIAG promoter via a specific CRE. These results suggest that PmDsx is engaged in male reproductive development and positively regulates the transcription of the PmIAG by specifically binding upstream of the promoter of the PmIAG. It provides a theoretical basis for exploring the sexual regulation pathway and evolutionary dynamics of Dmrt family genes in P. monodon. Full article

This article reported a compact ultra-thin tightly arranged 4 × 4 multiple-input multiple-output (MIMO) antenna pair (AP) functioning in the fifth-generation (5G) n78 band (3.4–3.6 GHz) for the ultra-thin 5G mobile handset. Two APs were printed on the center of two sideboards. A T-shaped open-ended slot was utilized in the grounding plane to improve the port impedance matching and attenuate the reciprocal magnetic coupling. A minimized total volume of 145 × 75 × 5 mm³ was obtained, and the area of each radiating unit was only 8.5 × 4.2 mm² (0.1λ₀ × 0.05λ₀, λ₀ is the free-space wavelength at the frequency of 3.5 GHz). By placing two radiating elements in an exceeding closed (1 mm or 0.01167λ₀) distance, the designed AP precisely resonated at 3.5 GHz, and an acceptable measured isolation performance superior to 17 dB was attained. A prototype of this presented APs system was printed and tested, and remarkable consistency was observed between the simulated and measured curves. Numerous indicators were computed to assess its MIMO performance, such as Envelope Correlation Efficiency (ECC), Diversity Gain (DG), Total Active Reflection Coefficient (TARC), and Multiplexing Efficiency (ME). Full article

Sacred lotus (Nelumbo nucifera) is an aquatic perennial plant with essential food, ornamental, and pharmacological value. Growth-regulating factor (GRF) is a transcription factor (TF) family that plays an important role in regulating the growth and development of plants. In this study, a comprehensive analysis of the GRF family in N. nucifera was performed, and its role in N. nucifera development was studied. A total of eight GRF genes were identified in the N. nucifera genome. Phylogenetic analysis divided the 38 GRF genes into six clades, while the NuGRFs only contained five clades. The analyses of gene structures, motifs, and cis-acting regulatory elements of the GRF gene family were performed. In addition, the chromosome location and collinearity were analyzed. The expression pattern based on transcriptomic data and real-time reverse transcription-quantitative PCR (qRT-PCR) revealed that the GRF genes were expressed in multiple organs and were abundant in actively growing tissues, and the expression levels decreased as the age of N. nucifera increased. Then, 3D structures of the NuGRF proteins were predicted by homology modeling. Finally, the subcellular localization of GRF1 was ascertained in the tobacco leaf through a vector. Therefore, this study provides a comprehensive overview of the GRF TF family in N. nucifera. Full article

This paper presents a dual-band four-element multiple-input-multiple-output (MIMO) array for the fifth generation (5G) mobile communication. The proposed antenna is composed of an open-loop ring resonator feeding element and a T-shaped radiating element. The utilization of the open-loop ring resonator not only reduces the size of the antenna element, but also provides positive cross-coupling. The dimension of a single antenna element is 14.9 mm × 7 mm (0.27λ × 0.13λ, where λ is the wavelength of 5.5 GHz). The MIMO antenna exhibits a dual-band feature from 3.3 to 3.84 GHz and 4.61 to 5.91 GHz, which can cover 5G New Radio N78 (3.3–3.8 GHz), 5G China Band N79 (4.8–5 GHz), and IEEE 802.11 ac (5.15–5.35 GHz, 5.725–5.85 GHz). The measured total efficiency and isolation are better than 70% and 15 dB, respectively. The calculated envelope correlation coefficient (ECC) is less than 0.02. The measured results are in good agreement with the simulated results. Full article

A quad-port antenna array operating in 3.5 GHz band (3.4–3.6 GHz) and 5 GHz band (4.8–5 GHz) for fifth-generation (5G) smartphone applications is presented in this paper. The single antenna element consists of an L-shaped strip, a parasitic rectangle strip, and a modified Z-shaped strip. To reserve space for 2G/3G/4G antennas, the quad-port antenna array is printed along the two long frames of the smartphone. The evolution design and the analysis of the optimal parameters of a single antenna element are derived to investigate the principle of the antenna. The prototype of the presented antenna is tested and the measured results agree well with the simulation. The measured total efficiency is better than 70% and the isolation is larger than 16.5 dB. Full article

Expansins, a group of cell wall-loosening proteins, are involved in cell-wall loosening and cell enlargement in a pH-dependent manner. According to previous study, they were involved in plant growth and abiotic stress responses. However, information on the biological function of the expansin gene in moso bamboo is still limited. In this study, we identified a total of 82 expansin genes in moso bamboo, clustered into four subfamilies (α-expansin (EXPA), β-expansin (EXPB), expansin-like A (EXLA) and expansin-like B (EXPB)). Subsequently, the molecular structure, chromosomal location and phylogenetic relationship of the expansin genes of Phyllostachys edulis (PeEXs) were further characterized. A total of 14 pairs of tandem duplication genes and 31 pairs of segmented duplication genes were also identified, which may promote the expansion of the expansin gene family. Promoter analysis found many cis-acting elements related to growth and development and stress response, especially abscisic acid response element (ABRE). Expression pattern revealed that most PeEXs have tissue expression specificity. Meanwhile, the expression of some selected PeEXs was significantly upregulated mostly under abscisic acid (ABA) and polyethylene glycol (PEG) treatment, which implied that these genes actively respond to expression under abiotic stress. This study provided new insights into the structure, evolution and function prediction of the expansin gene family in moso bamboo. Full article