Nonstationary two-stage multisplitting methods for symmetric positive definite matrices

AbstractNonstationary synchronous two-stage multisplitting methods for the solution of the symmetric positive definite linear system of equations are considered. The convergence properties of these methods are studied. Relaxed variants are also discussed. The main tool for the construction of the two-stage multisplitting and related theoretical investigation is the diagonally compensated reduction (cf. [1])

Transfer to the Collinear Libration Point L3 in the Sun-Earth+Moon System

The collinear libration point L3 of the sun-earth+moon system is an ideal place for some space missions. Although there has been a great amount of work concerning the applications of the other two collinear libration points L1 and L2, little work has been done about the point L3. In this paper, the dynamics of the libration points was briefly introduced first. Then a way to transfer the spacecraft to the collinear libration point L3 via the invariant manifolds of the other two collinear libration points was proposed. Theoretical works under the model of circular restricted three-body problem were done. For the sun-earth+moon system, this model is a good approximation. The results obtained are useful when a transfer trajectory under the real solar system is designed

A comparison of breastfeeding among Han, Uygur and other ethnic groups in Xinjiang, PR China

BACKGROUND: Breastfeeding is an important factor in infant health and there have been no previous studies of breastfeeding practices in the different ethnic groups of this region of China. We aimed to compare breastfeeding rates and duration between Han, Uygur and other ethnic groups living in Xinjiang, PR China. METHODS: A longitudinal study of infant feeding practices was undertaken using a sample that included different ethnic groups. Mothers were randomly recruited and interviewed in hospitals and after discharge were contacted in person or by telephone at approximately monthly intervals to obtain details of infant feeding practices. Setting: Xinjiang Uygur Autonomous Region, PR China. Subjects: A total of1219 mothers (578 Han, 360 Uygur and 281 'other minority' mothers) who delivered babies during 2003 and 2004 were interviewed in five hospitals or institutes located in both urban and rural areas. RESULTS: 'Any breastfeeding' rates in Han, Uygur and 'other minority' groups at discharge were 88.5 %, 94.3 % and 97.1 % respectively, and at six months 76.7 %, 54.7 % and 87.6 % respectively. While 'exclusive breastfeeding' rates in the Han, Uygur and 'other minority' groups at discharge were 78.0 %, 34.5 % and 83.1 % respectively, at six months they had fallen to 4.8 %, 0.4 % and 16.8 % respectively. The median duration of 'Exclusive breastfeeding' of Han, Uygur and 'other minority' babies were 1.5, 0.1 and 2.5 months respectively. The Uygur babies were least likely to be 'exclusive breastfed'. CONCLUSION: Uygur babies were least likely to be 'exclusive breastfed' and continued to 'any breastfeed' at six month. The 'any breastfeeding' rates in the Han group were lower in the first four months. An education program focused on breastfeeding continuation and exclusive breastfeeding is necessary in Xinjiang, especially for Uygur and Han ethnic groups

Curcumin combining with si-MALAT1 inhibits the invasion and migration of colon cancer SW480 cells

To study the effect of small interfering RNA targeting metastasis-associated lung adenocarcinoma transcript1 (si-MALAT1) combining with curcumin on the invasion and migration abilities of human colon cancer SW480 cells, and to explore the involved molecular mechanism. The recombinant lentiviral vector expressing si-MALAT1 was constructed, and its titer was determined by gradient dilution method. The colon cancer SW480 cells with stable expression of si-MALAT1 was established, followed by treatment with curcumin at different concentrations. The effect of curcumin or si-MALAT1 alone and the combination of the two on the cell activity was detected by MTT assay. The cell invasion and migration abilities were detected by transwell and scratch-wound assay. The relative expression level of MALAT1 was detected by RT-qPCR. The protein expression was determined by Western blot analysis. The IC50 of curcumin alone was 77.69 µmol/L, which was 51.17 mol/Lwhen combined with curcumin and random sequence. The IC50 of curcumin was 30.02 µmol/L when combined with si-MALAT1. The increased susceptibility multiples was 2.58. The wound healing rates were 30.9% and 67.5% after treatment with si-MALAT1 combined with curcumin for 24 hrs and 48 hrs, respectively. The numbers of invasion cells were 200±12, 162±13, 66±8, 53±4 and 16±3 after treatment with si-MALAT1 combined with curcumin for 48 hrs. The relative expression level of lncRNA-MALAT1 in the curcumin group was 68%, and the relative expression level of lncRNA-MALAT1 in si-MALAT1group was 56%, and that for the combination treatment group was about 21%. The protein expression levels of β- catenin, c-myc and cyclinD1 were significantly down-regulated upon treatment with certain concentration of si-MALAT1 alone or combined with curcumin.si-MALAT1 could significantly inhibit the invasion and migration of SW480 cells by enhancing the sensitivity of SW480 cells to curcumin. The mechanism involved mignt be related to the down-regulation of β-catenin, c-myc and cyclinD1 proteins

Alpha-lipoic acid induces apoptosis in hepatoma cells via the PTEN/Akt pathway

AbstractWe report here that alpha-lipoic acid (α-LA), a naturally-occurring antioxidant, scavenges reactive oxygen species (ROS) followed by an increase in apoptosis of human hepatoma cells. Apoptosis induced by α-LA was dependent upon the activation of the caspase cascade and the mitochondrial death pathway. α-LA induced increases in caspase-9 and caspase-3 but had no significant effect on caspase-8 activity. Apoptosis induced by α-LA was found to be mediated through the tensin homologue deleted on chromosome 10 (PTEN)/Akt pathway. Prior to cell apoptosis, PTEN was activated and its downstream target Akt was inhibited. Our findings indicate that increasing ROS scavenging could be a therapeutic strategy to treat cancer

Transcriptome Analysis of Metapenaeus affinis Reveals Genes Involved in Gonadal Development

Metapenaeus affinis is a crustacean with important commercial value in the fishery of the South China Sea. Overfishing has resulted in the decline of the wild population and germplasm degradation. However, there is little background knowledge about its gonadal development, and there is a lack of research on the development of this species. To better understand the molecular regulatory mechanisms during gonadal development, here, we performed RNA-Seq on immature and mature ovaries and compared their transcriptomic signatures. 126,930,488 and 122,677,356 clean sequencing reads were obtained from the Illumina sequencing platform, respectively. 394 differentially expressed genes (DEGs) were identified, of which 136 were up-regulated, and 258 were down-regulated. Further analysis revealed rich transcriptional sequences, which have homology with genes related to reproduction and development. Expression patterns of COX, GPX, E3s, PCNA, STPK, and other genes were changed during ovarian development. Validation by qRT-PCR demonstrated the reliability of RNA-Seq. This study has made a significant contribution to the currently available sequence data of M. affinis and provided reference data for the development of genetic and breeding work

The role of cellular oxidative stress in regulating glycolysis energy metabolism in hepatoma cells

<p>Abstract</p> <p>Background</p> <p>The Warburg effect has been found in a wide spectrum of human cancers, however the underlying mechanisms are still unclear. This study aims to explore the role of cellular oxidative stress in relation to glycolysis and the Warburg effect in hepatoma cells.</p> <p>Methods</p> <p>Various cell lines combining environmental hypoxia was used as an in vitro model to mimic tumor microenvironment in vivo. Superoxide dismutases (SOD) and xanthine oxidase (XO) gene transfection were used to produce various cellular redox levels. 2',7'-dichlorofluorescin (DCF) fluorescence and ESR spectrum were used to detect cellular reactive oxygen species (ROS).</p> <p>Results</p> <p>We found that endogenous or exogenous interference with the cellular oxidative stress can sensitively regulate glycolysis and the Warburg effect in hepatoma cells. Hepatoma cells displayed a high level of free radicals compared to immortalized normal hepatocyte cells. Increasing the level of ROS stress in hepatoma cells can directly upregulate HIF-1 and activate glycolysis without requirement of a hypoxic condition. This explains the mechanism whereby aerobic glycolysis, i.e. the Warburg effect arises. Either endogenously upregulating SOD or exogenously administration with antioxidant can, through downregulating ROS level, effectively regulate energy pathways in hepatoma cells and can inhibit the growth of tumor cells and xenograft tumors.</p> <p>Conclusion</p> <p>This study suggests that the Warburg effect was related to an inherently high level of cellular ROS and HIF-1. Hepatoma cells adaptation to hypoxia for survival and rapid growth exploits oxidative stress ectopically activated glycolysis to compensate the energy supply. This specific mechanism in which tumor cells through cellular oxidative stress activate glycolysis to meet their energy metabolism requirement could be exploited to selectively kill tumor cells.</p