The Experts below are selected from a list of 12972 Experts worldwide ranked by ideXlab platform
Kai Guo - One of the best experts on this subject based on the ideXlab platform.
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a squaramide and tertiary amine an excellent hydrogen Bonding Pair organocatalyst for living polymerization
Polymer Chemistry, 2015Co-Authors: Jingjing Liu, Cheng Chen, Xu Zhi, Qiguo Zhang, Xin Wang, Saide Cui, Kai GuoAbstract:A hydrogen-bond motif based on a squaramide and sparteine efficiently promoted the ring-opening polymerization of L-lactide at ambient temperature. Narrowly dispersed polymers with precise molar masses (Đ = 1.05, Mn = 16 240 g mol−1) were obtained in a short reaction time (98% conv., 11 h) and with retention of stereochemistry. Experimental data and computational results indicated that the squaramide and sparteine Pair is a competent H-bond donor–acceptor catalyst in living polymerization.
Tammy J Dwyer - One of the best experts on this subject based on the ideXlab platform.
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nmr solution structure of a dna actinomycin d complex containing a non hydrogen Bonding Pair in the binding site
Journal of the American Chemical Society, 2010Co-Authors: Shannen L Cravens, Alyssa C Navapanich, Bernhard H Geierstanger, Deborah C Tahmassebi, Tammy J DwyerAbstract:The solution structures of two different DNA duplexes (one containing a G-T mismatched base Pair and the other a non-hydrogen-Bonding G-F Pair, where F is difluorotoluene) in complex with the peptide antibiotic actinomycin D (ActD) are presented. Using 1H, 19F NMR, and molecular dynamics simulations, we show that there are three major differences between the complexes: (1) ActD binds to the GF duplex in an orientation that is flipped 180° relative to its position in the GT duplex; (2) whereas the difluorotoluene moiety takes the typical anti glycosidic conformation in the “free” (uncomplexed) GF duplex, it takes the syn conformation in the GF:ActD complex; and (3) in GF:ActD, the difluorotoluene moiety is completely unstacked in the helix; however, the guanine of the G-F Pair is stacked quite well with the ActD intercalator and the flanking base on the 5′ side. In GT:ActD, the G-T base Pair (although pushed into the major groove from the non-Watson−Crick hydrogen-Bonding pattern) stacks favorably with the...
Jingjing Liu - One of the best experts on this subject based on the ideXlab platform.
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a squaramide and tertiary amine an excellent hydrogen Bonding Pair organocatalyst for living polymerization
Polymer Chemistry, 2015Co-Authors: Jingjing Liu, Cheng Chen, Xu Zhi, Qiguo Zhang, Xin Wang, Saide Cui, Kai GuoAbstract:A hydrogen-bond motif based on a squaramide and sparteine efficiently promoted the ring-opening polymerization of L-lactide at ambient temperature. Narrowly dispersed polymers with precise molar masses (Đ = 1.05, Mn = 16 240 g mol−1) were obtained in a short reaction time (98% conv., 11 h) and with retention of stereochemistry. Experimental data and computational results indicated that the squaramide and sparteine Pair is a competent H-bond donor–acceptor catalyst in living polymerization.
Elizabeth Eadie - One of the best experts on this subject based on the ideXlab platform.
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why monogamy isn t good enough
American Journal of Primatology, 2016Co-Authors: Stacey R Tecot, Britt Singletary, Elizabeth EadieAbstract:Rare in mammals but more common in primates, there remains a considerable controversy concerning whether primate species traditionally described as monogamous actually express this highly specialized breeding pattern. Unfortunately the definition of “monogamy” varies greatly, inhibiting our understanding of this trait and two related traits with which monogamy is often conflated: Pair-living and Pair-Bonding. Strepsirrhine primates are useful models to study factors that select for Pair-living, Pair-Bonding, and monogamy because this taxon exhibits high incidences of each trait, in addition to species that exhibit behaviors that reflect combinations of these traits. Several hypotheses have been articulated to help explain the evolution of “monogamy,” but again, these hypotheses often conflate Pair-living, Pair-Bonding, and/or monogamy. In this review, we (1) propose clear, discrete, and logical definitions for each trait; (2) review variation in strepsirrhines with respect to these three traits; (3) clarify which of these traits can be explained by existing hypotheses; and (4) provide an example of the applicability of the Resource Defense Hypothesis (RDH) to understand two of these traits, Pair-living and Pair-Bonding, in the red-bellied lemur (Eulemur rubriventer). Available data support the RDH for Pair-living in red-bellied lemurs. They live in stable family groups with one adult Pair. Both sexes actively codefend territories that overlap little with other Pairs’ territories. Agonism is extremely rare within groups and intergroup and interspecific agonism varies with food availability. Available data also support the RDH for Pair-Bonding. Pair-bonds are cohesive year-round. Pairs coordinate behaviors to defend territories with auditory and olfactory signals. Cohesion increases with food abundance and both sexes reinforce bonds. We indicate where additional data will help to more rigorously test the RDH for each trait and encourage others to test alternative hypotheses. Am. J. Primatol. 78:340–354, 2016. © 2015 Wiley Periodicals, Inc.
Shannen L Cravens - One of the best experts on this subject based on the ideXlab platform.
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nmr solution structure of a dna actinomycin d complex containing a non hydrogen Bonding Pair in the binding site
Journal of the American Chemical Society, 2010Co-Authors: Shannen L Cravens, Alyssa C Navapanich, Bernhard H Geierstanger, Deborah C Tahmassebi, Tammy J DwyerAbstract:The solution structures of two different DNA duplexes (one containing a G-T mismatched base Pair and the other a non-hydrogen-Bonding G-F Pair, where F is difluorotoluene) in complex with the peptide antibiotic actinomycin D (ActD) are presented. Using 1H, 19F NMR, and molecular dynamics simulations, we show that there are three major differences between the complexes: (1) ActD binds to the GF duplex in an orientation that is flipped 180° relative to its position in the GT duplex; (2) whereas the difluorotoluene moiety takes the typical anti glycosidic conformation in the “free” (uncomplexed) GF duplex, it takes the syn conformation in the GF:ActD complex; and (3) in GF:ActD, the difluorotoluene moiety is completely unstacked in the helix; however, the guanine of the G-F Pair is stacked quite well with the ActD intercalator and the flanking base on the 5′ side. In GT:ActD, the G-T base Pair (although pushed into the major groove from the non-Watson−Crick hydrogen-Bonding pattern) stacks favorably with the...