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Aims: Salicylic acid (SA) and nitric oxide (NO) are key signal molecules involved in the reduction of Al accumulation in many plants. The purpose of this study was to investigate whether they could reduce the root content of Al and/or its binding to the root cell wall (CW) fractions in Panax notoginseng, and to investigate the corresponding regulatory mechanisms.Methods: Effects of Al treatments on the endogenous SA and NO contents of P. notoginseng were detected. Exogenous SA and paclobutrazol (PAC, a SA synthesis inhibitor) treatments were conducted to test the effects on endogenous NO content; exogenous sodium nitroprusside (SNP, a NO doner) and 2-phenyl-4,4,5,5-tetramethyl- imidazoline-1-oxyl-3-oxyde (cPTIO, a NO synthesis inhibitor) treatments were conducted to test the effects on endogenous SA content. Pectin methyltransferase (PMT) and pectin methylesterase (PME) activity and the gene expression, pectin methylesterification degree (PMD), pectin content, and the accumulation of Al in roots were also studied under the treatments described above.Results: Al stress induced a significant increase of the activity and expression of phenylalanine ammonia-lyase (PAL), and promoted the significant increase of endogenous SA content of P. notoginseng roots. The Al promoted accumulation of endogenous NO could be enhanced by exogenous SA treatment, but was reduced by PAC. Accumulation of endogenous NO that promoted by Al could be enhanced by exogenous SA treatment, but was reduced by PAC treatment. However, SNP or cPTIO treatments had no significant effect on the Al-induced endogenous SA content of P. notoginseng. This showed that NO acted downstream of SA signaling of P. notoginseng under Al stress. Al stress can increase the activity and genes expression of PME in the roots of P. notoginseng, reduce PMD, increase CW pectin content, and thus, the binding capacity of CW pectin to Al was enhanced in P. notoginseng roots. Exogenous SA or SNP both reduced the Al-binding capacity of root CW pectin by decreasing the pectin content, and increased the PMD by inhibiting the genes expression and activity of PME. The effects of PAC or cPTIO on the above-mentioned indicators under Al stress were opposite to that of exogenous SA or SNP treatments.Conclusions: The Al stress induced accumulation of pectin and the reduction of PMD in the root CW of P. notoginseng could be reversed by the treatments of exogenous SA or SNP, then the Al contents in root CW pectin were reduced. Al stress activated the endogenous SA and NO signaling pathways in P. notoginseng, and NO acted downstream of SA. It showed that the Al-activated NO-SA signaling pathway contributed in the reduction of Al binding to the root under Al stress. [ABSTRACT FROM AUTHOR]

The pentablock (PB) copolymers based composite nanosystems were designed to provide a long-term delivery of macromolecules to the back of the eye. A unique arrangement of each block (polyethylene glycol, polylactic acid, and polycaprolactone) with various molecular weights (PB-A and PB-B) was selected for the synthesis of nanoparticles (NPs) and thermosensitive gel (PB-C) by sequential ringopening bulk copolymerization reaction. PB copolymers were characterized for their molecular weight and purity by 1H- NMR spectroscopy and crystallinity by PXRD. The macromolecule model drugs [lysozyme (Lyz ~ 14.5 kDa), IgG-Fab (~ 50 kDa), and IgG (~ 150 kDa)] were selected to delineate the effect of molecular weights on in vitro release profile of nanoformulations. Lyz-, Fab-, and IgG-encapsulated NPs were prepared by double emulsion solvent evaporation method. The entrapment efficiency (EE%) and drug loading (DL%) of macromolecules was higher for PB-B copolymers due to its higher molecular weight and hydrophobicity compare to PB-A. The particle size range of NPs was ~ 200- 270 nm. In vitro release profiles of Lyz-, Fab-, and IgGencapsulated in NPs alone and NPs suspended in gel (composite nanosystem) demonstrated a minimal burst release and drug release over a long period. The effect of hydrodynamic diameter of macromolecules and hydrophobicity of PB copolymers was investigated on the release profile of nanosystems. In vitro biocompatibility study showed negligible cytokine (IL-1, IL-6, and TNF-α) release, which confirmed the safety of the PB copolymers. Based on the results, it is anticipated that long-term ocular delivery of macromolecules can be achieved through composite nanosystems. [ABSTRACT FROM AUTHOR]

Aims: Panax notoginseng is normally cultivated in acidic red soil with high soluble Al, however, the distribution pattern of Al in P. notoginseng is unknown. The aim of this study is to investigate the Al distribution in different organs of P. notoginseng grown in different acid soil, in order to get a deeper insight into the Al tolerance mechanism in this species.Methods: P. notoginseng was sampled from different sites and subjected to Al determination. Al tolerance and accumulation were investigated by exposing the seedlings to different Al concentrations in hydroponic solution. The expression of pectin methylesterase genes was determined by quantitative RT-PCR.Results: The soil pH ranged from 4.68 to 6.13. The total Al concentration in soil was 76.7-168.5 g·kg−1 and active Al was 1.34-5.01 g·kg−1. Al concentration differed with organs of P. notoginseng, following the order: rootlet > rhizome > main root > leaf and stem. Furthermore, Al concentration in the cell wall, organelle and cytoplasmic supernatant of P. notoginseng was approximately 15:2:1 and most Al in the cell wall was bound to pectin component. Al treatment significantly increased the content of pectin and enhanced the expression of PME3, PME7, and PME40 of P. notoginseng root.Conclusions: P. notoginseng was able to grow under high active Al condition and accumulated high Al in its underground parts. The pectin component in the cell wall was the major binding site of Al of P. notoginseng root. [ABSTRACT FROM AUTHOR]

Intrinsic radiosensitivity of normal and tumour tissues has been shown to be an independent prognostic factor for patients' response to radiotherapy. This study compares the real-time cell-impedance sensing (RT-CES) assay with the conventional clonogenic assay in terms of in-vitro radiosensitivity. One objective in this study was to predict in-vivo response to gold nanoparticle (GNP) treatment on the basis of in-vitro RT-CES testing results. Four adenocarcinoma cancer cell lines were tested using both the RT-CES and the clonogenic assays. Cell-survival curves were plotted, and the mean SF2 values obtained by these two different assay methods were compared using ANOVA. Radiation sensitivities obtained in-vitro were then compared with the in-vivo results. On the basis of the measurement of cell colonies, the RT-CES assay has similar radiosensitivity to the clonogenic assay, but significantly shortens the testing time from 14-21 days to only 72 h. Intrinsic GNP enhanced radiation sensitivity using tumour volume (mm) in vivo is comparable with that using RT-CES cell survival assay in vitro. Furthermore, the RT-CES system provides real-time information regarding the state of cell radiosensitivity that may give useful information towards personalizing radiotherapy. The RT-CES assay enables more reliable and time-efficient results in the evaluation of radiosensitivity. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Using a probability sample of 4,230 adolescents from grades 7–12, we used negative binomial regression to estimate the effects of peer and six family variables on the risk of adolescent drug use. Peer drug use had relatively strong effects of adolescent drug use. Parental drug attitudes, sibling drug use, and adult drug use had significant direct effects net of peer influences. In addition, they had significant indirect effects that were mediated by peer drug use. The influences of parental monitoring, attachment to mother, and attachment to father were statistically significant but relatively small. The findings applied to alcohol, binge drinking, cigarettes, marijuana, and other illicit drugs. [ABSTRACT FROM AUTHOR]

Noodles have been a popular staple food in many parts of the world for at least 2,000 years, although it is debatable whether the Chinese, the Italians or the Arabs invented them first. Here we analyse a prehistoric sample of noodles contained in a well preserved, sealed earthenware bowl discovered in the Late Neolithic archaeological site of Lajia in northwestern China. We identify millet as the source of the abundant seed-husk phytoliths and starch grains present in the vessel. This shows that the conversion of ground millet flour into dough that could be repeatedly stretched into long, thin strands for the preparation of boiled noodles was already established in this region 4,000 years ago. [ABSTRACT FROM AUTHOR]