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991.
This study examines characteristics of atmospheric methylsiloxane pollution in indoor settings where interior renovation/redecoration is being undertaken, in addition to ordinary family homes and inside family cars. Concentrations of atmospheric methylsiloxane in these locations were approximately one order of magnitude higher than that in outdoor areas. The average indoor concentration of methylsiloxane where renovation was being undertaken was 9.4 μg/m3, which is slightly higher than that in an ordinary family home (7.88 μg/m3), while samples from family cars showed lower concentration (3.10 μg/m3). The indoor atmospheric concentration during renovation/redecoration work was significantly positively correlated with the duration of the work. The structure of atmospheric methylsiloxane pollution is basically the same in these three venues. The concentration of annulus siloxane was much higher than that of linear compounds (85% of the total methylsiloxane concentrations). Household dust in average family homes showed total methylsiloxane concentration of 9.5 μg/m3 (average); the structure mainly consisted of linear siloxane (approximately 98% of total concentration), thereby differing from that of atmospheric methylsiloxane pollution. The comparatively high concentration of methylsiloxane in these three venues indicates that interior renovation and decoration work, and even travelling in cars, can involve exposure to more serious siloxane contamination during everyday activities.  相似文献   
992.
Myostatin (MSTN) is a member of the transforming growth factor-β superfamily which negatively regulates growth of muscle tissue. In this study, 103 cultivated Chlamys farreri individuals were screened for polymorphisms in the MSTN gene using PCR-single strand conformation polymorphism (PCR-SSCP) and DNA sequencing methods. Two mutations were found: A/G at position 327 in exon 2, which caused an amino acid change from Thr to Ala (Thr305Ala), and C/T at position 289 in exon 3, which caused an amino acid change from Cys to Arg (Cys422Arg). One way ANOVA of the SNPs and growth traits showed that genotype GG of primer M5 had significantly higher body mass, soft-tissue mass, adductor muscle mass, shell length, shell height, absolute growth rate of shell height and body mass than those of genotype AG and AA (P < 0.05). Genotype frequencies of genotype AA, AG and GG were 68.94%, 27.18% and 3.88%, respectively. The results present evidence that the C. farreri MSTN gene may be selected as a candidate gene for these growth traits.  相似文献   
993.
PI3K activation is commonly observed in many human cancer cells. Survivin expression is elevated in cancer cells, and induced by some growth factors through PI3K activation. However, it is not clear whether PI3K activation is sufficient to induce survivin expression. To investigate the role of PI3K pathway in the regulation of survivin, we expressed an active form of PI3K, v-P3k in chicken embryonic fibroblast cells (CEF), and found that overexpression of PI3K-induced survivin mRNA expression. Forced expression of wild-type but not mutant tumor suppressor PTEN in CEF decreased survivin mRNA levels. PI3K regulates survivin expression through Akt activation. To further investigate downstream target of PI3K and Akt in regulating the expression of survivin mRNA, we found that PI3K and Akt-induced p70S6K1 activation and that overexpression of p70S6K1 alone was sufficient to induce survivin expression. The treatment of CEF cells by rapamycin decreased the survivin mRNA expression. This result demonstrated that p70S6K1 is an important target downstream of PI3K and Akt in regulating suvivin mRNA expression. The knockdown of survivin mRNA expression by its specific siRNA induced apoptosis of cancer cells when the cells were treated with LY294002 or taxol. Taken together, these results demonstrated that PI3K/Akt/p70S6K1 pathway is essential for regulating survivin mRNA expression.  相似文献   
994.
? Premise of the study: Parthenocissus is a genus of the grape family Vitaceae and has a disjunct distribution in Asia and North America with members in both tropical and temperate regions. The monophyly of Parthenocissus has not yet been tested, and the species relationships and the evolution of its intercontinental disjunction have not been investigated with extensive sampling and molecular phylogenetic methods. ? Methods: Plastid (trnL-F, rps16, and atpB-rbcL) and nuclear GAI1 sequences of 56 accessions representing all 12 Parthenocissus species were analyzed with parsimony, likelihood, and Bayesian inference. Divergence times of disjunct lineages were estimated with relaxed Bayesian dating. Evolution of the leaflet number was assessed by tracing this character onto Bayesian trees using the Trace Character Over Trees option in the program Mesquite. ? Key results: Parthenocissus is monophyletic and sister to the newly described segregate genus Yua. Two major clades within Parthenocissus are recognizable corresponding to their distribution in Asia and North America. The disjunction between the two continents is estimated to be at 21.64 (95% higher posterior densities 10.23-34.89) million years ago. ? Conclusions: Parthenocissus is likely to have derived from the Eocene boreotropical element. Its current Asian-North American disjunction is dated to the early Miocene, congruent with fossil and paleoclimatic evidence. The tropical species is nested within the temperate clade and is inferred to have dispersed from the adjacent temperate regions. Parthenocissus and Yua are best treated as distinct genera. Leaflet number in this genus has a complex history and cannot be used as a character for infrageneric classification.  相似文献   
995.
Glycosides, 3-acetyl-(?)-epicatechin 7-O-β-glucopyranoside (1), 3-acetyl-(?)-epicatechin 7-O-(6-isobutanoyloxyl)-β-glucopyranoside (2), 3-acetyl-(?)-epicatechin 7-O-[6-(2-methyl-butanoyloxyl)]-β-glucopyranoside (3), (5Z)-6-[5-(2-hydroxypropan-2-yl)-2-methyl-tetrahydrofuran-2-yl]-3-methylhexa-1,5-dien-3-O-β-glucopyranoside (4), hydroquinone O-[6-(3-hydroxyisobutanoyl)]-β-galactopyranoside (5), 4-(4-O-β-glucopyranosyl-phenoxy)-1-O-β-glucopyranosyl-1,3-benzenediol (6), 7,8-erythro-dihydroxy-3,4,5-trimethoxy-phenyl-propane8-O-β-glucopyranoside (7), 6,7-dimethylbenzofuranol 5-O-β-xylopyranosyl-(1  6)-β-glucopyranoside (8), along with 30 known glycosides, were isolated from Breynia fruticosa and Breynia rostrata (Euphorbiaceae). Their structures were determined on the basis of spectroscopic analysis and chemical methods.  相似文献   
996.
997.
998.
This study introduced a kind of new SNP genotyping strategy in genetic analysis of Chinese shrimp (Fenneropenaeus chinensis). Twenty SNP tetra-primer ARMA-PCR primer sets were validated and used to investigate the genetic structure of six selected families of marine shrimp F. chinensis. The effective number of alleles ranged from 1.127 to 1.993, with an average value of 1.600. The average values of expected and observed heterozygosities of the SNPs ranged from 0.505∼0.609 and 0.373∼0.487, respectively. Polymorphism information content (PIC) values ranged from 0.145 to 0.373. Among 120 population-locus cases (six populations × twenty loci), only 8 (6.7%) showed significant deviation (P < 0.05), while the other 112 (93.3%) were in Hardy-Weinberg equilibrium (HWE) (P > 0.05). The frequencies of minor alleles ranged from 0.378 to 0.497. For the six families, the wild genotype and its allele frequency were significantly higher than that of the mutant genotype and its allele frequency. Fifty five point forty two percent of the population-locus showed heterozygosity. The results indicated that tetra-primer ARMA-PCR is a simple, rapid and efficient method for SNP genotyping which make it useful in a broad aspects of F. chinensis genetic and breeding studies.  相似文献   
999.
1000.
The genus Dichocarpum is endemic to East Asia, and many species have been used to treat various diseases. However, phytochemical researches of this genus have been limited to date. In the present study, a metabolomic approach based on UPLC-Q-TOF-MS/MS was used to explore the phytochemical profiles of 10 Chinese Dichocarpum species, and cannabinoid receptor (CB1/CB2) agonistic activities evaluation of these plants was performed. A total of 128 features were putatively annotated, belonging to alkaloids, flavonoids, triterpenes saponins, phenolic acids, and others. Semi-quantitative statistics demonstrated that alkaloids and flavonoids were widely distributed, with the former the most abundant, whereas triterpenes saponins were mainly distributed in D. fargesii and D. wuchuanense. The phylogenetic results obtained from DNA sequencing assigned the 10 species to three groups. Further results of in silico annotation revealed three chemical families and helped determine the characteristic features of the three groups. In addition, the plant extracts of nine species from this genus showed agonistic activity on CB2 receptors. This comprehensive analysis revealed the chemotype distribution and pharmacophylogenetic relationship, to provide clues for the prospective resource utilization of the medicinal plants from the genus Dichocarpum.  相似文献   
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