73 resultados para Supramolecular association


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Objective: To investigate the association of complement C4 null genes (C4QO, including C4AQO and C4BQO) and C2 gene with systemic lupus erythematosus (SLE) in southwest Han Chinese; 136 patients with SLE and 174 matched controls were genotyped. Methods: C4 null genes were determined by a polymerase chain reaction (PCR) procedure with sequence specific primers (PCR-SSP). The 2 bp insertion in exon 29, which was previously identified in non-Chinese populations and caused defective C4A genes, was directly typed by sequencing the whole exon 29 using exon specific primers. The exon 6 of complement C2 was also sequenced in both the patients and controls. Results: The frequency of homozygous C4AQO allele was 12.5% (17/136) in patients with SLE compared with 1.1% (2/174) in controls (p<0.001, odds ratio (OR)=12.286, 95% confidence interval (95% CI) 2.786 to 54.170). There was no significant difference for homozygous C4BQO allele between patients with SLE and controls (p=0.699). Patients with the C4AQO gene had an increased risk of acquiring renal disorder, serositis, and anti-dsDNA antibodies compared with those without C4AQO (for renal disorder, p=0.018, OR=8.951, 95% Cl 1.132 to 70.804; for serositis, p=0.011, OR 4.891, 95% CI 1.574 to 15.198; for anti-dsDNA, p=0.004, OR 7.630, 95%Cl 1.636 to 35.584). None of the patients or controls had the 2 bp insertion in exon 29 of the C4 gene. The type I C2 deficiency was not detected in the 3 10 samples. Conclusion: It is suggested that deficiency of C4A (not due to a 2 bp insertion in exon 29), but not C4B or C2, may be a risk factor for acquiring SLE in south west Han Chinese; this results in increased risk of renal disorder, serositis, and anti-dsDNA antibodies in patients with SLE. Racial differences seem to be relevant in susceptibility to SLE.

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Background: The aim of this study is to screen single nucleotide polymorphisms (SNP) of chicken Calpain3 (CAPN3) gene and to analyze the potential association between CAPN3 gene polymorphisms and carcass traits in chickens. We screened CAPN3 single nucleo

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To investigate the differential expression of genes in the skeletal muscle between Yorkshire and Chinese indigenous breed Meishan pigs, suppression subtractive hybridization was carried out and many genes were proved to be expressed significantly different in the two breeds. One gene highly expressed in Meishan but lowly expressed in Yorkshire specific library, shared strong homology with human pyruvate dehydrogenase kinase 4 (PDK4). Using semi-quantity and quantity PCR, We confirmed its differential expression between the two breeds. Temporal and spatial expression analysis indicated that porcine PDK4 gene is highly expressed in skeletal muscle and the highest in neonatal pigs. Complete cDNA cloning and sequence analysis revealed that porcine PDK4 gene contains an open reading frame of 1,221 bp. The deduced amino acid sequence showed conservation in evolution. A G/A mutation in intron 9 was identified and association analysis showed that it was significantly associated with intramuscular fat, muscle water content.

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8-hydroxy-2'-deoxyguanosine (8OHdG) has been widely used as a biomarker of oxidative DNA damage in both animal models and human studies. To evaluate the effect of cigarette smoking on oxidative stress, we studied the levels of urinary 8OHdG from smokers and non-smokers and investigated the association with cigarette smoking. The urinary 8OHdG concentrations were determinated by capillary electrophoresis with end-column amprometric detection (CE-AD) after a single-step solid phase extraction (SPE), and then quantitatively expressed as a function of creatinine excretion. To increase the concentration sensitivity, a dynamic pH junction was used and the focusing effect was obvious when using 30 mM phosphate (pH 6.50) as sample matrix. The limit of detection is 4.3 nM (signal-to-noise ratio S/N = 3). The relative standard deviation (R.S.D.) was 1.1% for peak current, and 2.3% for migration time. Based on the selected CE-AD method, it was found that the mean value of urinary 8OHdG levels in the smokers significantly higher than that in non-smokers (31.4 +/- 18.9 nM versus 14.4 +/- 7.6 nM, P = 0.0004; 23.5 +/- 21.3 mug g(-1) creatinine versus 12.6 +/- 13.2 mug g(-1) creatinine, P = 0.028). (C) 2004 Elsevier B.V. All rights reserved.

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We have developed a novel strategy for the preparation of ion-bonded supramolecular star polymers by RAFT polymerization. An ion-bonded star supramolecule with six functional groups was prepared from a triphenylene derivative containing tertiary amino groups and trithiocarbonate carboxylic acid, and used as the RAFT agent in polymerizations of tert-butyl acrylate (tBA) and styrene (St). Molecular weights and structures of the polymers were characterized by H-1 NMR and GPC. The results show that the polymerization possesses the character of living free-radical polymerization and the ion-bonded supramolecular star polymers PSt, PtBA, and PSt-b-PtBA, with six well-defined arms, were successfully synthesized.

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Amphiphilic supramolecular miktoarm star copolymers linked by ionic bonds with controlled molecular weight and low polydispersity have been successfully synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization using an ion-bonded macromolecular RAFT agent (macro-RAFT agent). Firstly, a new tetrafunctional initiator, dimethyl 4,6-bis(bromomethyl)-isophthalate, was synthesized and used as an initiator for atom transfer radical polymerization (ATRP) of styrene to form polystyrene (PSt) containing two ester groups at the middle of polymer chain. Then, the ester groups were converted into tertiary amino groups and the ion-bonded supramolecular macro-RAFT agent was obtained through the interaction between the tertiary amino group and 2-dodecylsulfanylthiocarbonylsulfanyl-2-methyl propionic acid (DMP). Finally, ion-bonded amphiphilic miktoarm star copolymer, (PSt)(2)-poly(N-isopropyl-acrylamide)(2), was prepared by RAFT polymerization of N-isopropylacrylamide (NIPAM) in the presence of the supramolecular macro-RAFT agent. The polymerization kinetics was investigated and the molecular weight and the architecture of the resulting star polymers were characterized by means of H-1-NMR, FTIR, and GPC techniques. (c) 2008 Wiley Periodicals, Inc.

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Here, we report the first example that one enantiomer of a supramolecular cylinder can selectively stabilize human telomeric G-quadruplex DNA. The P-enantiomer of this cylinder has a strong preference for G-quadruplex over duplex DNA and, in the presence of sodium, can convert G-quadruplexes from an antiparallel to a hybrid structure. The compound's chiral selectivity and its ability to discriminate quadruplex DNA have been studied by DNA melting, circular dichroism, gel electrophoresis, fluorescence spectroscopy and S1 nuclease cleavage.

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A supramolecular complex [Cu(phen)(2)H2O]{[Cu(phen)(H2O)](2)[C6AS]}center dot 2.5H(2)O (phen = 1,10'-phenanthroline and C6AS = p-sulfonatocalix[6]arene) has been synthesized under hydrothermal condition, and characterized by IR spectroscopy, TG analysis and single crystal X-ray diffraction. In the structure, unprecedented 1D ({[Cu(phen)(H2O)](2)[C(6)AS]}(2-))(n) coordination chains (exactly being belts) are stacked into some 2D layers by the pi center dot center dot center dot pi stacking interactions, which are further interconnected into a 3D extended structure by hydrogen bonding.

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Three new copper compounds, Cu-2[C12H8N2](2)[C28H2OS4O16][H2O](11.9) (1), Cu-2[C12H8N2](3)[C28H20S4O16][H2O](5) (2), and Cu-2[C12H8N2](4)[C24H12S8O16][H2O](10.5) (3), were hydrothermally synthesized and structurally determined by X-ray diffraction and TG-DTA analyses. Interestingly, Compounds 1 and 2 were synthesized in a one-pot reaction. Complexes 1 and 3 contain capsule units, which are further assembled into three-dimensional (3-D) architectures with a-Po-related topology by pi-pi stacking and/or hydrogen-bonding interactions.