1,560 research outputs found

    Polymerase-endonuclease amplification reaction for large-scale enzymatic production of antisense oligonucleotide

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    Synthetic oligonucleotides are contaminated with highly homologous failure sequences. Oligonucleotide synthesis is difficult to scale up because it requires expensive equipments, hazardous chemicals, and tedious purification process. Here we report a novel thermocyclic reaction, polymerase-endonuclease amplification reaction (PEAR), for the amplification of oligonucleotides. A target oligonucleotide and a tandem repeated antisense probe are subjected to repeated cycles of denaturing, annealing, elongation and cleaving, in which thermostable DNA polymerase elongation and strand slipping generate duplex tandem repeats, and thermostable endonuclease (PspGI) cleavage releases monomeric duplex oligonucleotides. Each round of PEAR achieves >100-fold amplification. The product can be used in one more round of PEAR directly, and the process can be further repeated. In addition to avoiding dangerous materials and improved product purity, this reaction is easy to scale up and amenable to full automation, so it has the potential to be a useful tool for large-scale production of antisense oligonucleotide drugs

    A new Late Devonian genus with seed plant affinities

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    Background: Many ovules of Late Devonian (Famennian) seed plants have been well studied. However, because few taxa occur with anatomically preserved stems and/or petioles, the vascular system of these earliest spermatophytes is little understood and available data come mostly from Euramerica. There remains great controversy over the anatomical differentiation of Late Devonian and Carboniferous seed plant groups of Buteoxylonales, Calamopityales and Lyginopteridales. Protostele evolution of these early spermatophytes needs more research. Results: A new taxon Yiduxylon trilobum gen. et sp. nov. with seed plant affinities has been discovered in the Upper Devonian (Famennian) Tizikou Formation of Hubei Province, China. It is represented by stems, helically arranged and bifurcate fronds with two orders of pinnae and planate pinnules. Both secondary pinnae and pinnules are borne alternately. Stems contain a small protostele with three primary xylem ribs possessing a single peripheral protoxylem strand. Thick secondary xylem displays multiseriate bordered pitting on the tangential and radial walls of the tracheids, and has biseriate to multiseriate and high rays. A narrow cortex consists of inner cortex without sclerotic nests and sparganum-type outer cortex with peripheral bands of vertically aligned sclerenchyma cells. Two leaf traces successively arise tangentially from each primary xylem rib and they divide once to produce four circular-oval traces in the stem cortex. Four vascular bundles occur in two C-shaped groups at each petiole base with ground tissue and peripheral bands of sclerenchyma cells. Conclusions: Yiduxylon justifies the assignment to a new genus mainly because of the protostele with protoxylem strands only near the periphery of primary xylem ribs, leaf trace origination and petiolar vascular supply structure. It shares many definitive characters with Calamopityales and Lyginopteridales, further underscoring the anatomical similarities among early seed plants. The primary vascular system, pycnoxylic-manoxylic secondary xylem with bordered pits on both tangential and radial walls of a tracheid and leaf trace divergence of Yiduxylon suggest transitional features between the early spermatophytes and ancestral aneurophyte progymnosperms.Evolutionary BiologyGenetics & HereditySCI(E)[email protected]

    Slow lies: response delays promote perceptions of insincerity

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    Evaluating other people’s sincerity is a ubiquitous and important part of social interactions. Fourteen experiments (total N = 7565; ten preregistered; eleven in the main paper, three in the SOM; with U.S. American and British members of the public, and French students) show that response speed is an important cue on which people base their sincerity inferences. Specifically, people systematically judged slower (vs. faster) responses as less sincere for a range of scenarios from trivial daily conversations to high stakes situations such as police interrogations. Our findings suggest that this is because slower responses are perceived to be the result of the responder suppressing automatic, truthful thoughts, and fabricating a novel answer. People also seem to have a rich lay theory of response speed, which takes into account a variety of situational factors. For instance, the effect of response delay on perceived sincerity is smaller if the response is socially undesirable, or if it can be attributed to mental effort. Finally, we showed that explicit instructions to ignore response speed can reduce the effect of response speed on judgments on sincerity. Our findings not only help ascertain the role of response speed in interpersonal inference making processes, but also carry important practical implication. In particular, the present study highlights the potential effects that may be observed in judicial settings, since the response speed of innocent suspects may mislead people to judge them as insincere and hence guilty

    ISOKINETIC PEAK TORQUE OF CONCENTRIC AND ECCENTRIC CONTRACTION

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    The purpose of this study was to examine the isokinetic peak torque of plantar flexion and dorsiflexion in male and female. Seventy college students volunteered to participate in this study. Cybex-6000 dynamometer was employed in this study to examined the isokinetic concentric (CON) and eccentric (ECC) strength of ankle plantar flexion and dorsiflexion at 60, 120, 180, 240, and 300/s. Peak torques (PT) and peak torques relative to body mass for ankle plantar flexion and dorsiflexion were studied. The results indicated that ECC PT was greater than CON PT and plantar flexion PT was greater than dorsiflexion PT in both females and males. The ECC PT did not increase with increasing angular velocity. This study also showed that it was more reasonable to normalize PT relative to body mass when comparing the differences of strength between males and females

    EFFECTS OF MOVEMENT RANGE ON PEAK TORQUE DURING ISOKINETIC KNEE FLEXION AND EXTENSION

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    INTRODUCTION: The knee joint is one of the biggest and most complex joints of the body. Optimal function of the knee joint is closely related with the physical performance and the outcome of sporting activity. Consequently, there have been many studies related to the muscles of the knee joint. The majority of these have focused on 90°range of knee movement, and the same start-angle and end-angle. However, during normal exertion and in sports, different actions require a different range of movement of the knee joint. In addition, the muscular force and velocity are also different. Therefore, in this paper, the biomechanical characteristics of knee muscles in different ranges were studied

    An Event History Analysis of Divorce in China

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    Ironic effects of thought suppression: a meta-analysis

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    The ironic effect of thought suppression refers to the phenomenon in which individuals trying to rid their mind of a target thought ironically experience greater levels of occurrence and accessibility of the thought compared to individuals that deliberately concentrate on the thought (Wegner, 1994). Ironic effects occurring after thought suppression, also known as rebound effects, have been consistently detected by previous meta-analyses. However, ironic effects that occur during thought suppression, also known as immediate enhancement effects, have been found to be largely absent. In the current meta-analysis, we test Wegner’s original proposition that detection of immediate enhancement effects is dependent on the cognitive load experienced by individuals when enacting thought suppression. Given that thought suppression is an effortful cognitive process, it is proposed that the introduction of additional cognitive load would compete for the allocation of existing cognitive resources and impair capacity for thought suppression. Studies (k = 31) consistent with Wegner’s original thought suppression paradigm were analysed. Consistent with our predictions, rebound effects were observed regardless of cognitive load while immediate enhancement effects were only observed in the presence of cognitive load. Implications are discussed in light of ironic process theory and suggestions for future thought suppression research provided
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