The Thermal Stabilization Effect of Biphenol Monoacrylate on Polyoxymethylene

2009 ◽  
Vol 23 (4) ◽  
pp. 543-559 ◽  
Author(s):  
Lu Gan ◽  
Lin Ye
2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
Aishwarya Prakash ◽  
Fabien Kieken ◽  
Luis A. Marky ◽  
Gloria E. O. Borgstahl

Replication protein A (RPA) plays an essential role in DNA replication by binding and unfolding non-canonical single-stranded DNA (ssDNA) structures. Of the six RPA ssDNA binding domains (labeled A-F), RPA-CDE selectively binds a G-quadruplex forming sequence (5′-TAGGGGAAGGGTTGGAGTGGGTT-3′called Gq23). In K+, Gq23 forms a mixed parallel/antiparallel conformation, and in Na+Gq23 has a less stable (TMlowered by ∼20∘C), antiparallel conformation. Gq23 is intramolecular and 1D NMR confirms a stable G-quadruplex structure in K+. Full-length RPA and RPA-CDE-core can bind and unfold the Na+form of Gq23 very efficiently, but complete unfolding is not observed with the K+form. Studies with G-quadruplex ligands, indicate that TMPyP4 has a thermal stabilization effect on Gq23 in K+, and inhibits complete unfolding by RPA and RPA-CDE-core. Overall these data indicate that G-quadruplexes present a unique problem for RPA to unfold and ligands, such as TMPyP4, could possibly hinder DNA replication by blocking unfolding by RPA.


2002 ◽  
Vol 21 (3) ◽  
pp. 353-361 ◽  
Author(s):  
S. Jipa ◽  
T. Zaharescu ◽  
R. Setnescu ◽  
T. Setnescu ◽  
J. Herdan ◽  
...  

2015 ◽  
Vol 88 (9) ◽  
pp. 1539-1550 ◽  
Author(s):  
Jianping Liu ◽  
Xia Song ◽  
Mingpei Tang ◽  
Hongzhou Shang ◽  
Li Yan

2017 ◽  
Vol 15 (9) ◽  
pp. 2073-2085 ◽  
Author(s):  
Maria Ejlersen ◽  
Niels Langkjær ◽  
Jesper Wengel

Synthesis of a novel 3′-pyrene-functionalized UNA monomer with unprecedented thermal stabilization of duplexes and triplexes.


2021 ◽  
Vol 2063 (1) ◽  
pp. 012005
Author(s):  
Hikmat A Ali ◽  
Hussein A Shnawa ◽  
Dhiaa A Abidalimam

Abstract In this study, calcium complex of anthocyanin was synthesized from anthocyanin, a flavonoid type natural phenolic product, which was extracted from eggplant peel. The structure of Ca-anthocyanin was characterized by FTIR spectroscopy. Its efficiency as bio-based thermal stabilizer to stabilize poly (vinyl chloride) was investigated and compared to that of Reapak B-NT/7060, a Ca/Zn-based commercial stabilizer. The influence of Ca-anthocyanin complex on the thermal degradation reaction of PVC was monitored by differential scanning calorimetry (DSC). The results indicated that the Ca-anthocyanin complex is an efficient thermal stabilizer and it reduces the rate of dehydrochlorination reaction of PVC already at a concentration as small as 2 phr, part per hundred of PVC resin. The thermal degradation reaction of PVC through the first degradation stage is clearly limited by the addition of Ca-anthocyanin complex as single (primary) stabilizer. Its efficiency is similar to that of Reapak B-NT/7060 used as reference stabilizer and it can enhance the performance of commercial stabilizer when used as co-stabilizer at mixing ratio (1:1). This study has allowed verifying and validating the usefulness of environmental friendly thermal stabilizer for PVC with very evident stabilization effect.


2012 ◽  
Vol 15 (3) ◽  
pp. 215-223 ◽  
Author(s):  
J.L. Contreras ◽  
M.A. Ortiz ◽  
R. Luna ◽  
G.A. Fuentes ◽  
M. Autié ◽  
...  

An stabilization effect of WOx over the Pt/hydrotalcite catalysts to produce H2 by ethanol steam reforming at low concentration was studied. The catalysts were characterized by N2 physisorption, X-ray diffraction, Infrared (IR), and UV-vis spectroscopy. The catalytic tests were made in a fixed bed reactor. The catalysts showed porous with the shape of parallel layers with a monomodal mesoporous distribution. By IR spectroscopy it was found superficial chemical such as: -OH, H2O, Al-OH, Mg-OH, and CO32-. The reaction products were; H2, CO2, CH3CHO, CH4 and C2H4. These catalysts did not produce CO and showed low selectivity to C2H4. By XRD we found that catalysts having Pt and the lowest W concentration showed the highest crystallinity and the highest stability during the reaction of ethanol steam reforming. A possible thermal stabilization effect of W in the hydrotalcite crystal structure leading to prevent the Pt sintering is proposed. By IR the hydrotalcite hydroxil groups coordinated with Mg and Al decreased by the presence of WOx. We found that catalysts with low W concentration and Pt having high crystallinity showed the highest stability after ethanol steam reforming. It could be a possible thermal stabilization effect of W in the hydrotalcite crystal structure leading to prevent the Pt sintering.


2012 ◽  
Vol 581-582 ◽  
pp. 81-84
Author(s):  
Jian Ping Liu ◽  
Hong Zhou Shang ◽  
Xia Song ◽  
Wei Yuan ◽  
Shu Mei Zhou

Bis (mercaptoethanol oleate) dimethyl tin was synthesized and added to polyvinyl chloride (PVC) with various ratios. Specimens were prepared by mixing and rolling through a double-roller mixer, and their static thermal stabilities were estimated by the oven static thermal aging experiments. The influence of the bis (mercaptoethanol oleate) dimethyl tin on the dynamic thermal stability of PVC was tested through a haack torque rheometer (HAAKE PolyLab QC). The tensile strength and rate of elongation at break of the PVC specimens were evaluated by a servo-controlled tensile testing machine. The results show that the bis (mercaptoethanol oleate) dimethyl tin has excellent static and dynamic thermal stabilization effect on PVC, and to some extent, can improve the breaking elongation rate the PVC sample.


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