Theoretical calculations and photoluminescence properties of Sr4Al14O25:Mn4+ red phosphors doped with Li.

The absence of high-efficiency oxide red phosphors restricts the development of high-performance solid-state lighting. In this work, a series of Li+ doped Sr4Al14O25:Mn4+ (SAO-Li+) red phosphors were prepared. Theoretical calculation results indicate that Li+ is inclined to occupy the gap 2 position. The low concentration Li+ gap doping has almost no influence on the Sr4Al14O25 structure, and a 0.4 mol Li+-doped sample exhibits a pure phase with regular morphology. With increasing Li+ doping content, the luminescence intensities of phosphors increase first and then decrease. 0.4 mol is found to be the optimal concentration. The fluorescence lifetime continues to decrease with the increase in the Li+ doping content and a mutation occurs at 0.5 mol Li+. Phosphor doping with Li+ can improve the thermal quenching resistance. The WLED device encapsulated with SAO-0.4Li and YAG:Ce3+ phosphors prepared showed a correlated color temperature of 4667 K, a color rendering index of 82, and a light efficiency of 137.34 lm W-1 at a driving current of 20 mA. The above results indicate that the use of a SAO-0.4Li+ phosphor is expected for application in warm WLEDs.

Chemical Composition of Tobacco Seed Oils and Their Antioxidant, Anti-Inflammatory, and Whitening Activities.

Tobacco seeds are a valuable food oil resource, and tobacco seed oil is rich in nutrients, especially polyunsaturated fatty acids. The aim of this work was to perform a comprehensive study on the chemical constituents, and the antioxidant, anti-inflammatory, and whitening activities of tobacco seed oils (NC89 and BS4). A GC/MS analysis revealed that NC89 and BS4 had 11 and 6 volatile compounds, respectively. The PUFA contents in NC89 and BS4 were 74.98% and 72.84%, respectively. These two tobacco seed oils also presented good radical scavenging capacities with the neutralization of ABTS, OH-, and superoxide (O2-) radicals in a concentration-dependent manner. Meanwhile, NC89 and BS4 inhibited reactive oxygen species (ROS) accumulation and cell apoptosis, enhanced SOD and CAT activities, and increased the GSH content in H2O2-induced HepG2 cells. In addition, NC89 and BS4 exhibited significant anti-inflammatory activities by inhibiting the expressions of NO, TNF-α, IL-1ß, and IL-6 in LPS-induced RAW.264.7 cells through the regulation of the MAPK signaling pathway. Moreover, NC89 and BS4 expressed whitening activities by inhibiting tyrosinase activity and intracellular melanin production. Therefore, tobacco seed oils could be used as an important oil resource for the development of high value-added products.

The complete chloroplast genome sequence of Nicotiana debneyi (Solanaceae).

In present study, we report the complete chloroplast genome of Nicotiana debneyi, a species endemic to eastern coast of Australia. The total genome size of N.debneyi is 156,073 bp in length, containing a large single-copy region of 86,672 bp, a small single-copy region of 18,581 bp, and two inverted repeat regions of 25,410 bp. The all GC content of N.debneyi chloroplast genome is 38.4%. It encodes a total of 129 unique genes, including 84 protein-coding genes, 37 tRNA genes, and eight rRNA genes, of which seven tRNA, four rRNA and seven protein-coding genes are duplicated in the IR. Sixteen genes contain a single intron, and only two genes have two introns. Phylogenetic analysis results strongly supported that N.debneyi was closely related to Nicotiana sylvestris and Nicotiana tabacum.

Effects of hypoxia-inducible factor-1α silencing on drug resistance of human pancreatic cancer cell line Patu8988/5-Fu.

The present study aimed to investigate the mechanism and the possible approaches of solving drug resistance by silencing hypoxia-inducible factor-1 alpha of human pancreatic cancer cell line Patu8988/5-Fu cultured in hypoxia. The effective jamming fragment screened by RT-PCR for silencing HIF-1α gene was transfected into pancreatic cancer cells Patu8988/5-Fu through lentivirus. RT-PCR results showed that the effective jamming fragments for HIF-1α in lentivirus transfection was Wtl-mus-1202(C546). Combined MTT with JC-1 fluorescence staining flow cytometric analysis, the concentration of 200 µmol/L CoCl2 for 8 h was chosen to mimic hypoxia cell environment. The drug resistance significantly enhanced in response to hypoxia in Patu8988/5-Fu (p<0.05), and silence HIF-1α could reverse the multidrug resistance (P<0.05). In the Patu8988/5-Fu cells, HIF-1α and MDR1 significantly increased in response to hypoxia (p<0.05). The inhibition of HIF-1α expression synergistically downregulated the expression of the MDR1 gene in Patu8988/5-Fu cells (p<0.05). HIF-1α expression was positively correlated with the MDR1 expression (p<0.05). The upregulation of the HIF-1α and MDR1 gene expression caused by hypoxia was related with the generation of multi-drug resistance of Patu8988/5-Fu, targeted silencing HIF-1α may be a kind of way to reverse the chemotherapy drug resistance.

Allelopathic enhancement and differential gene expression in rice under low nitrogen treatment.

The allelopathy-competition separation (ACS) based approach was used to explore the biointerference relationship between rice accessions and barnyardgrass exposed to different nitrogen (N) supplies in hydroponics. Rice accession PI312777 exhibited high allelopathic potential to suppress the growth of accompanying weeds, especially when the culture solution had low N content. The non-allelopathic rice Lemont showed an opposite result. Additionally, subtractive hybridization suppression (SSH) was used to construct a forward SSH-cDNA library of PI312777 to investigate gene expression profiles under low N treatment. A total of 35 positive clones from the SSH-cDNA library were sequenced and annotated. According to the function category, 24 genes were classified into five groups related to primary metabolism, phenolic allelochemical synthesis, plant growth/cell cycle regulation, stress response/signal transduction, and protein synthesis/degradation. Among them, two up-regulated genes that encode PAL and cytochrome P450 were selected. Their transcript abundance at low N level was compared further between the allelopathic rice and its counterpart by utilizing real-time quantitative polymerase chain reaction (qRT-PCR). The transcription levels of the two genes increased in both rice accessions when exposed to low N supply, but PI312777 at a higher magnitude than Lemont. At 1, 3, and 7 days of the treatments, the corresponding relative expression levels of PAL were 11.38, 4.83, and 3.57 fold higher in PI312777 root, but there were 1.15, 2.74, and 2.94 fold increases for Lemont, compared with the control plants fed with regular nutrient. The same trend was found for cytochrome P450. These findings suggest that the stronger ability of PI312777 to suppress target weeds, especially in low N nutrient conditions, might be attributed to the stronger activation of the genes that function in de novo synthesis of allelochemicals.

[Interactive effects between allelochemical substitutes].

In order to understand the allelopathic mechanisms of rice on weed, the allelochemical substitutes salicylic acid, p-hydroxybenzonic acid, cinnamic acid, vanillic acid and ferulic acid were used in an orthogonally gyrating regression experiment to study their interactive effects on the growth of barnyardgrass. The results indicated that whether the interactive effects between two substitutes, e.g., between salicylic and cinnamic acid or between salicylic and p-hydrobanzonic acid, were synergistic or antagonistic depended on the concentrations of each substitutes in the mixture. In the mixture of salicylic acid and p-hydrobanzonic acid, the effect of salicylic acid was synergistic at < 0.14 mmol.L(-1) but antagonistic at > 0.14 mmol.L(-1), while p-hydrobanzonic acid showed an antagonistic effect at > 0.425 mmol.L(-1). Salicylic acid at all test concentrations exhibited antagonism to cinnamic acid, while cinnamic acid had a synergistic at < 0.14 mmol.L(-1), but an antagonistic effect at >0.14 mmol.L(-1) on alicylic acid. The interactive effects between cinnamic and ferulic acid were all synergistic at test concentrations.

[Assesment of genetic diversity of allelopathic rice germplasm based on RAPD and ISSR].

Random Amplified Polymorphic DNA (RAPD) and Inter-simple Sequence Repeat (ISSR) methods were used to detect the genetic diversity of 57 allelopathic rice accessions which were introduced from 10 countries or areas. A total of 12 RAPD primers and seven ISSR primers were indentified with polymorphism among the entries. For RAPD markers, 85 polymorphic bands were produced, percentage of polymorphic bands (PPB) were 69.4%. For ISSR marker, 34 polymorphic bands were generated, PPB were 53.0%. The result from the clustering analysis by UPGMA indicated that those accessions from the same geographical location were clustered into one group. It was also found that some rice accessions with higher allelopathic potential were clustered together, implying that the genes conferring allelopathy in those rice accessions might be isolocus. However, some rice accessions with different allelopathic potential clustered into the same group performed lower level of generic polymorphism which was attributed to oriented selection for other traits in breeding program. The estimates of correlation coefficient of RAPD and ISSR based on the genetic similarity matrices were significantly correlated.

[Weed-suppressive effect of phenolic acids].

Allelochemical substitutions salicylic acid, p-hydroxybenzonic acid, cinnamic acid, vanillic acid and ferulic acid were tested in a gyrating regression experiment to study the weed-suppressive effect of phenolic acids on the root growth of barnyardgrass. The results showed that cinnamic acid had a significant inhibitory effect, its square item regression coefficient being -6.18; salicylic acid, p-hydroxybenzonic acid and ferulic acid had the same trend of weed-suppressive potential as cinnamic acid, while vanillic acid had a different weed-suppressive effect from the others. The inhibition rate (IR) on the root growth of barnyardgrass reached its highest level (78.5%) when 0.06 mmol x L(-1) salicylic acid, 0.60 mmol x L(-1) p-hydrobenzonic acid, 0.24 mmol x L(-1) cinnamic acid, 0.02 mmol x L(-1) vannillic acid and 0.02 mmol x L(-1) ferullic acid were mixed together to apply.