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Polymerization-induced self-assembly of 2-hydroxypropyl methacrylate is conducted in water and water/MeOH using a CO2 -responsive macroRAFT agent in the form of a statistical copolymer comprising N,N-diethylaminoethyl methacrylate (DEAEMA) and poly(ethylene glycol) methyl ether methacrylate (M n  = 475 g mol-1 ). Pressurization with CO2 leads to protonation of DEAEMA units within the stabilizer block, thereby offering a means of adjusting the charge density of the coronal layer. It is demonstrated that a wide range of tunable particle morphologies are accessible by simply varying the CO2 pressure during polymerization in the range of 10-45 bar.

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We demonstrate the deposition of mechanically robust UV-absorbing nanocomposite coatings with a newly developed dual-source deposition method involving ultrasonic spraying and open-air plasma deposition. Nanoparticles and the coating matrix are independently deposited which eliminates difficulties associated with preparing composites with high mass fraction of well-dispersed nanoparticles in the matrix. Nanocomposite coatings containing different concentrations of silica, ceria, and both titania and ceria nanoparticles were successfully deposited with good nanoparticle dispersity, high transparency over the visible range, effective absorption in the UV wavelength, and enhanced mechanical properties. Moreover, films were successfully deposited on several substrates including polycarbonate to demonstrate the low processing temperature of this dual-source deposition method. Coatings with different nanoparticle concentrations and film thicknesses were systematically studied in terms of their surface morphology, optical properties and mechanical properties. Accelerated photostability testing of the UV-absorbing nanocomposites demonstrates significantly enhanced performance compared to existing coatings with either a polymeric matrix or organic UV-absorbers.

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The synthesis of polymeric nanocapsules in the approximate diameter range 40-100 nm (TEM/SEM) using catanionic surfactant vesicle templates stabilized by subcritical CO2 is demonstrated. Near equimolar aqueous solutions of the surfactants sodium dodecyl sulfate (SDS) and dodecyltrimethylammonium bromide (DTAB) experienced immediate vesicle destabilization and precipitation in the absence of CO2. However, pressurization with CO2 (5 MPa) dramatically enhanced the stability of the initial vesicles, and enabled swelling of the bilayers with hydrophobic monomers via diffusion loading (loading of monomers into preformed bilayers). Subsequent radical crosslinking polymerization of the monomers n-butyl methacrylate/tert-butyl methacrylate/ethylene glycol dimethacrylate contained within the bilayers was conducted at room temperature using UV-initiation under CO2 pressure. The hollow structure of the resultant nano-objects was confirmed by successful encapsulation and retention of the dye Nile Blue. It is demonstrated that using this method, polymeric nanocapsules can be successfully prepared using diffusion loading of up to 94 wt% monomer (rel. to surfactant) stabilized by CO2.

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We demonstrate a dual organic and inorganic precursor method to deposit transparent organosilicate protective bilayer coatings on poly methyl methacrylate (PMMA) substrates with atmospheric plasma deposition in ambient air. The bottom layer was a hybrid organosilicate adhesive layer deposited with dual organic 1,5-cyclooctadiene (CYC) and widely used inorganic tetraethoxysiline (TEOS) precursors. The selection of the organic CYC precursor allowed incorporation of a carbon chain in the organosilicate adhesive layer, which resulted in improved adhesion. The top layer was a dense silica coating with high Young's modulus and hardness deposited with TEOS. The deposited bilayer structure showed ∼100% transparency in the visible light wavelength region, twice the adhesion energy, and five times the Young's modulus of commercial polysiloxane sol-gel coatings.

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Heat shock proteins (HSPs) are molecular chaperones and have an important role in the refolding and degradation of misfolded proteins, and these functions are related to aging. Rotifer is a useful model organism in aging research, owing to small body size (0.1-1 mm), short lifespan (6-14 days), and senescence phenotypes that can be measured relatively easily. Therefore, we used rotifer as a model to determine the role of four typical hsp genes on the aging process in order to provide a better understanding of rotifer aging. We cloned cDNA encoding hsp genes (hsp40, hsp60, hsp70, and hsp90) from the rotifer Brachionus calyciflorus Pallas, analyzed their molecular characteristics, determined its modulatory response under different temperatures and H2O2 concentrations and investigated the changes in expression of these genes during the aging process. We found that Bchsp70 mRNA expression significantly decreased with aging. In addition, we also studied the effects of dietary restriction (DR) and vitamin E on rotifer lifespan and reproduction and analyzed the changes in expression of these four Bchsp genes in rotifers treated with DR and vitamin E. The results showed that DR extended the lifespan of rotifers and reduced their fecundity, whereas vitamin E had no significant effect on rotifer lifespan or reproduction. Real-time PCR indicated that DR increased the expression of these four Bchsps. However, vitamin E only improved the expression of Bchsp60, and reduced the expression of Bchsp40, Bchsp70, and Bchsp90. DR pretreatment also increased rotifer survival rate under paraquat-induced oxidative stress. These results indicated that hsp genes had an important role in the anti-aging process.

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Rotifers are useful model organisms for aging research, owing to their small body size (0.1-1 mm), short lifespan (6-14 days) and the relative easy in which aging and senescence phenotypes can be measured. Recent studies have shown that antioxidants can extend the lifespan of rotifers. In this paper, we analyzed changes in the mRNA expression level of genes encoding the antioxidants manganese superoxide dismutase (MnSOD), copper and zinc SOD (CuZnSOD) and catalase (CAT) during rotifer aging to clarify the function of these enzymes in this process. We also investigated the effects of common life-prolonging methods [dietary restriction (DR) and resveratrol] on the mRNA expression level of these genes. The results showed that the mRNA expression level of MnSOD decreased with aging, whereas that of CuZnSOD increased. The mRNA expression of CAT did not change significantly. This suggests that the ability to eliminate reactive oxygen species (ROS) in the mitochondria reduces with aging, thus aggravating the damaging effect of ROS on the mitochondria. DR significantly increased the mRNA expression level of MnSOD, CuZnSOD and CAT, which might explain why DR is able to extend rotifer lifespan. Although resveratrol also increased the mRNA expression level of MnSOD, it had significant inhibitory effects on the mRNA expression of CuZnSOD and CAT. In short, mRNA expression levels of CAT, MnSOD and CuZnSOD are likely to reflect the ability of mitochondria to eliminate ROS and delay the aging process.

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Superoxide dismutase (SOD, EC 1.15.1.1) is an important antioxidant enzyme that protects organs from damage by reactive oxygen species (ROS). We cloned cDNA encoding SOD activated with copper/zinc (CuZn SOD) from the rotifer Brachionus calyciflorus Pallas. The full-length cDNA of CuZn SOD was 692bp and had a 465bp open reading frame encoding 154 amino acids. The deduced amino acid sequence of B. calyciflorus CuZn SOD showed 63.87%, 60.00%, 59.74% and 48.89% similarity with the CuZn SOD of the Ctenopharyn godonidella, Schistosoma japonicum, Drosophila melanogaster and Caenorhabditis elegans, respectively. The phylogenetic tree constructed based on the amino acid sequences of CuZn SODs from B. calyciflorus and other organisms revealed that rotifer is closely related to nematode. Analysis of the expression of CuZn SOD under different temperatures (15, 30 and 37°C) revealed that its expression was enhanced 4.2-fold (p<0.001) at 30°C after 2h, however, the lower temperature (15°C) promoted CuZn SOD transiently (4.1-fold, p<0.001) and then the expression of CuZn SOD decreased to normal level (p>0.05). When exposed to H2O2 (0.1mM), CuZn SOD, manganese superoxide dismutase (Mn SOD) and catalase (CAT) gene were upregulated, and in addition, the mRNA expression of CuZn SOD gene was induced instantaneously after exposure to vitamin E. It indicates that the CuZn SOD gene would be an important gene in response to oxidative and temperature stress.

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Superoxide dismutase (SOD) is an important antioxidant enzyme that protects organs from damage by reactive oxygen species. We cloned cDNA encoding SOD activated with manganese (Mn-SOD) from the rotifer Brachionus calyciflorus Pallas. The full-length cDNA of Mn-SOD was 1,016 bp and had a 669 bp open reading frame encoding 222 amino acids. The deduced amino acid sequence of B. calyciflorus Mn-SOD showed 89.1, 71.3, and 62.1 % similarity with the Mn-SOD of the marine rotifer Brachionus plicatilis, the nematode Caenorhabditis elegans, and the fruit fly Drosophila melanogaster, respectively. The phylogenetic tree constructed based on the amino acid sequences of Mn-SODs from B. calyciflorus and other organisms revealed that this rotifer is closely related to nematodes. Analysis of the mRNA expression of Mn-SOD under different conditions revealed that expression was enhanced 5.6-fold (p < 0.001) at 30 °C after 2 h, however, low temperature (15 °C) promoted Mn SOD temporarily (2.5-fold, p < 0.001) and then decreased to normal level (p > 0.05). Moderate starvation promoted Mn-SOD mRNA expression (p 12 < 0.01, p 36 < 0.05), which reached a maximum value (15.3 times higher than control, p 24 < 0.01) at 24 h. SOD and CAT activities also elevated at the 12 h-starved group. These results indicate that induction of Mn-SOD expression by stressors likely plays an important role in aging of B. calyciflorus.

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A series of Cu-Fe bimetal amidoximated polyacrylonitrile (PAN) fiber complexes with different molar ratios of Cu(2+) to Fe(3+) ions was prepared using a simple exhaustion method, and characterized using FTIR, DRS and XPS, respectively. Then they were tested as the heterogeneous Fenton catalysts for Rhodamine B degradation with H(2)O(2) in the dark and under visible light irradiation. The results indicated that Cu-Fe bimetal amidoximated PAN fiber complexes could more effectively catalyze the dye degradation in water than Fe amidoximated PAN fiber complex, especially in the dark. And introduction of Cu(2+) ions significantly increased their catalytic performance. 0.56 was the optimum molar ratio of Cu(2+) to Fe(3+) ions to achieve the best catalytic activity and stability. This was mainly due to the synergetic effect in the bimetal complexes. Visible light irradiation improved the catalytic activity of the complexes, especially with a low molar ratio of Cu(2+) to Fe(3+) ions.

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