68 research outputs found

    Linear and Nonlinear Stability Analysis of Double Diffusive Convection in a Maxwell Fluid Saturated Porous Layer with Internal Heat Source

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    The onset of double diffusive convection is investigated in a Maxwell fluid saturated porous layer with internal heat source. The modified Darcy law for the Maxwell fluid is used to model the momentum equation of the system, and the criterion for the onset of the convection is established through the linear and nonlinear stability analyses. The linear analysis is obtained using the normal mode technique, and the nonlinear analysis of the system is studied with the help of truncated representation of Fourier series. The effects of internal Rayleigh number, stress relaxation parameter, normalized porosity, Lewis number, Vadasz number and solute Rayleigh number on the stationary, and oscillatory and weak nonlinear convection of the system are shown numerically and graphically. The effects of various parameters on transient heat and mass transfer are also discussed and presented analytically and graphically

    Identification of genes regulated by Wnt/β-catenin pathway and involved in apoptosis via microarray analysis

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    BACKGROUND: Wnt/β-catenin pathway has critical roles in development and oncogenesis. Although significant progress has been made in understanding the downstream signaling cascade of this pathway, little is known regarding Wnt/β-catenin pathway modification of the cellular apoptosis. METHODS: To identify potential genes regulated by Wnt/β-catenin pathway and involved in apoptosis, we used a stably integrated, inducible RNA interference (RNAi) vector to specific inhibit the expression and the transcriptional activity of β-catenin in HeLa cells. Meanwhile, we designed an oligonucleotide microarray covering 1384 apoptosis-related genes. Using oligonucleotide microarrays, a series of differential expression of genes was identified and further confirmed by RT-PCR. RESULTS: Stably integrated inducible RNAi vector could effectively suppress β-catenin expression and the transcriptional activity of β-catenin/TCF. Meanwhile, depletion of β-catenin in this manner made the cells more sensitive to apoptosis. 130 genes involved in some important cell-apoptotic pathways, such as PTEN-PI3K-AKT pathway, NF-κB pathway and p53 pathway, showed significant alteration in their expression level after the knockdown of β-catenin. CONCLUSION: Coupling RNAi knockdown with microarray and RT-PCR analyses proves to be a versatile strategy for identifying genes regulated by Wnt/β-catenin pathway and for a better understanding the role of this pathway in apoptosis. Some of the identified β-catenin/TCF directed or indirected target genes may represent excellent targets to limit tumor growth

    Investigating the involvement of potato (Solanum tuberosum L.) StPHR1 gene in the combined stress response to phosphorus deficiency and aluminum toxicity

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    Phosphorus deficiency and aluminum toxicity in acidic soils are important factors that limit crop yield. To further explore this issue, we identified 18 members of the StPHR gene family in the potato genome in this study. Through bioinformatics analysis, we found that the StPHR1 gene, an important member of this family, exhibited high expression levels in potato roots, particularly under conditions of phosphorus deficiency and aluminum toxicity stress. This suggested that the StPHR1 gene may play a crucial regulatory role in potato’s resistance to phosphorus deficiency and aluminum toxicity. To validate this hypothesis, we conducted a series of experiments on the StPHR1 gene, including subcellular localization, GUS staining for tissue expression, heterologous overexpression, yeast two-hybrid hybridization, and bimolecular fluorescence complementation (BiFC). The results demonstrated that the StPHR1 gene is highly conserved in plants and is localized in the nucleus of potato cells. The heterologous overexpression of the gene in Arabidopsis plants resulted in a growth phenotype that exhibited resistance to both aluminum toxicity and phosphorus deficiency. Moreover, the heterologous overexpressing plants showed reduced aluminum content in the root system compared to the control group. Furthermore, we also identified an interaction between StPHR1 and StALMT6. These results highlight the potential application of regulating the expression of the StPHR1 gene in potato production to enhance its adaptation to the dual stress of phosphorus deficiency and high aluminum toxicity in acidic soils

    Immunohistochemical Evaluation of Histological Change in a Chinese Milroy Disease Family With Venous and Skin Abnormities

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    Background: Milroy disease (MD) is rare and autosomal dominant resulting from mutations of the vascular endothelial growth factor receptor-3 (VEGFR-3 or FLT4), which leads to dysgenesis of the lymphatic system.Methods: Here we report a Chinese MD family with 2 affected members of two generations. We identified the mutation of c.3075G>A in one allele of FLT4 in Chinese population firstly. The father and child presented lymphedema under knees both. Unfortunately, the child was premature delivered for a car accident of the mother and then died of asphyxia. Then we gathered the tissue of the lower-limb from the child with permission from the parents and ethic committee. We stained the tissue with lymphatic marker D2-40 and hematoxylin-eosin to explore the histological changes. Afterwards, we compared the results with a normal child who unfortunately died of premature delivery also.Results: It is firstly identified the mutation of FLT4: c.3075G>A in Chinese population, and the mutation Inherited in the lineage. The histological evaluation indicated: (1) The number of lymphatic vessels decreased; (2) The morphology and structure of lymphatic vessels was abnormal. And what is added to our knowledge: (1) Capillary hyperemia and phlebectasia is severe; (2) Vascular malformations; (3) The number of vascular endothelial cells and vascular smooth muscle cells decreased; (4) Large sheets of epidermis desquamated; (5) The numbers of cutaneous appendages reduced in MD.Conclusions: Based on the new findings, we assume that mutation of FLT4 not only affect the lymphogenesis, but also the angiogenesis, and epidermis structure

    Transcriptome and network analyses reveal key pathways and genes involved in response to carotenoid deposition in scallop muscle

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    Carotenoids are essential nutrients for humans and animals, and carotenoid content has become an important trait to evaluate the nutritional value of many cultured animals. Marine animals provide humans with diverse carotenoids, and developing carotenoid-enriched varieties has been the focus of marine animal breeding. Understanding the molecular mechanism of carotenoid deposition could benefit marine animal breeding for carotenoid content improvement. In the present study, transcriptomic analysis of adductor muscle was performed between Yesso scallop (Patinopecten yessoensis) with white muscle (WM) and carotenoid-enriched orange muscle (OM). A total of 683 differentially expressed genes (DEGs) were identified, with 302 and 381 genes being up- and down-regulated in OM scallop. Gene co-expression network analysis identified four carotenoid accumulation−related modules, including three up-regulated modules and one down-regulated module. The genes in up-regulated modules mainly participate in the pathways of translation and transcription (MEgreen), immune system (MElightyellow), and lipid metabolism (MEpink), while the down-regulated module is mainly enriched with genes involved in various metabolic pathways (MEturquoise). As the causal gene responsible for muscle coloration in scallop, PyBCO-like 1 is the hub gene of MEturquoise and showed strong connectivity with NR2F1A, a transcriptional factor involved in the regulation of retinoic acid. In addition, the up-regulated DEGs, including WDR3, RPP29, TBL3, RIOK2, and NOB1 from “ribosome biogenesis”, HSP70s and HSP702Bs from “antigen processing and presentation”, and ACOX1 from “PPAR signaling pathway” were identified as hub genes, indicating the potential regulatory role of these genes and pathways in response to carotenoid accumulation. Our data contribute to a deeper understanding of the regulatory and response mechanisms of carotenoid accumulation in marine animals

    Full-length transcriptome analysis provides insights into larval shell formation in Mulinia lateralis

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    Mollusca is the second largest animal phylum and represents one of the most evolutionarily successful animal groups. Mulinia lateralis, a small bivalve, is a promising model organism to facilitate studies of mollusc development. However, because of the lack of published genomic and transcriptomic resources, integrated research on the formation of larval shells in this species, which is a representative developmental process of molluscs and of great importance for larva survival, is hindered. In this study, the blastula, gastrula, trochophore larva, and D-shaped larva of M. lateralis were utilized for generating a comprehensive full-length transcriptome through Pacific BioSciences (PacBio) isoform sequencing (Iso-seq) and Illumina RNA-Seq. A total of 238,919 full-length transcripts with an average length of 3,267 bp and 121,424 annotated genes were obtained. Illumina RNA-Seq data analysis showed that 4,512, 10,637, and 17,829 differentially expressed genes (DEGs) were obtained between the two adjacent developmental stages. Functional annotation and enrichment analysis revealed the specific function of genes in shell biomineralization during different developmental stages. Twelve genes that may be involved in the formation of the larval shell of M. lateralis were identified, including insoluble shell matrix protein-encoding gene 1 (ISMP1), ISMP2, ISMP5, chitin synthase, tyrosinase, chitin-binding protein, collagen and pu14 involved in shell matrix deposition, and carbonic anhydrase, solute carrier family 4 member 8 (slc4a8), EF-hand, and a calmodulin coding gene C-2442 participated in ion transportation. In addition, calcium ion binding function, calcium signaling pathway, and endocrine and other factor-regulated calcium reabsorption pathways were significantly enriched. Weighted gene correlation network analysis (WGCNA) identified two modules related to biomineralization and larval shell formation, and slc4a8 and ring finger protein 41 (rnf41) were key hub genes that may be involved in this process. Moreover, it could be implied that the process of ion transport occurs earlier than the deposition of the shell matrix. This work provided a clear view of the transcriptome for M. lateralis and will be valuable in elucidating the mechanisms of larval shell formation as well as other developmental processes in molluscs

    IL28B Genetic Variation Is Associated with Spontaneous Clearance of Hepatitis C Virus, Treatment Response, Serum IL-28B Levels in Chinese Population

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    <p><b>Background:</b> The interleukin-28B gene (IL28B) locus has been associated with host resistance to hepatitis C virus (HCV) infection and response to PEG-IFN/RBV treatment in western populations. This study was to determine whether this gene variant is also associated with spontaneous clearance of HCV infection, treatment response and IL-28B protein production in Chinese patients.</p> <p><b>Methods:</b> We genotyped IL28B genetic variations (rs12980275, rs8103142, rs8099917 and rs12979860) by pyrosequencing DNA samples from cohorts consisting of 529 subjects with persistent HCV infection, 196 subjects who cleared the infection, 171 healthy individuals and 235 chronic HCV patients underwent IFN/RBV treatment. The expression of IL-28B were measured by ELISA and RT-PCR.</p> <p><b>Results:</b> We found that the four IL28B variants were in complete linkage disequilibrium (r2 = 0.97–0.98). The rs12979860 CC genotype was strongly associated with spontaneously HCV clearance and successful IFN/RBV treatment compared to the CT/TT. IL-28B levels in persistent HCV patients were significantly lower than subjects who spontaneously resolved HCV and healthy controls and were also associated with high levels of ALT (alanine aminotransferase) and AST (aspartate aminotransferase). IL-28B levels were also significantly lower in individuals carrying T alleles than CC homozygous.</p> <p><b>Conclusions:</b> Thus, the rs12979860-CC variant upstream of IL28B gene is associated with spontaneous clearance of HCV, susceptible to IFN/RBV treatment and increased IL-28B levels in this Chinese population.</p&gt
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