Technicolor corrections on Bs,d→γγB_{s,d} \to \gamma\gamma decays in QCD factorization

Within the framework of the Top-color-assisted Technicolor (TC2) model, we calculate the new physics contributions to the branching ratios \calb(B_{s,d} \to \gamma \gamma) and CP violating asymmetries \rcpm(B_{s,d} \to \gamma \gamma) in the QCD factorization based on the heavy-quark limit $m_b \gg \Lambda_{QCD}$. Using the considered parameter space, we find that (a) for both $B_s\to \gamma \gamma$ and $B_d \to \gamma \gamma$ decays, the new physics contribution can provide a factor of two to six enhancement to their branching ratios, (b) for the $B_s \to \gamma \gamma$ decay, its direct CP violation is very small in both the SM and TC2 model, and (c) the CP violating asymmetry \rcpm(B_d \to \gamma \gamma) is around the ten percent level in both the SM and TC2 model, but the sign of CP asymmetry in the TC2 model is different from that in the SM.Comment: 23 pages, Revtex, 9 PS/EPs figures, minor corrections, final version to appear in Phys.Rev.

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

High-throughput first-principle prediction of collinear magnetic topological materials

Abstract The success of topological band theory and symmetry-based topological classification significantly advances our understanding of the Berry phase. Based on the critical concept of topological obstruction, efficient theoretical frameworks, including topological quantum chemistry and symmetry indicator theory, were developed, making a massive characterization of real materials possible. However, the classification of magnetic materials often involves the complexity of their unknown magnetic structures, which are often hard to know from experiments, thus, hindering the topological classification. In this paper, we design a high-throughput workflow to classify magnetic topological materials by automating the search for collinear magnetic structures and the characterization of their topological natures. We computed 1049 chosen transition-metal compounds (TMCs) without oxygen and identified 64 topological insulators and 53 semimetals, which become 73 and 26 when U correction is further considered. Due to the lack of magnetic structure information from experiments, our high-throughput predictions provide insightful reference results and make the step toward a complete diagnosis of magnetic topological materials

Electroacupuncture Pretreatment Alleviates Cerebral Ischemia-Reperfusion Injury by Increasing GSK-3β Phosphorylation Level via Adenosine A1 Receptor

Objective. To observe the effect of adenosine A1 receptor in the hippocampus of mice on GSK-3β phosphorylation level and elucidate the underlying mechanisms of electroacupuncture pretreatment by activating Α1 receptor mediating cerebral ischemia-reperfusion injury. Method. The model of middle cerebral artery occlusion (MCAO) was established and grouped into electroacupuncture pretreatment group (EA group), MCAO group, and sham-operated group (Sham group). The neurobehavioral manifestation, the volume of cerebral infarction, and its related protein changes in mice in each group were observed. Then, adenosine Α1 receptor antagonist and agonist were injected intraperitoneally to observe the effects of A1 receptor on the phosphorylation level of GSK-3β, neurobehavioral changes, and infarction volume. Results. (1) Compared with the MCAO group (24 hours after reperfusion), the infarct size in the EA group decreased significantly, and the Garcia neurological score and phosphorylation level of GSK-3β are increased. (2) Compared with the EA group, the infarct size in the A1 receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX) group increased significantly, and the Garcia neurological score and phosphorylation level of GSK-3β are decreased. (3) Compared with the MCAO group, the infarct size in the A1 receptor agonist 2-Chloro-N6-cyclopentyladenosine (CCPA) group decreased significantly, and the Garcia neurological score and phosphorylation level of GSK-3β are increased. There was no significant difference between the EA group and CCPA group. Conclusions. Electroacupuncture pretreatment can increase GSK-3β phosphorylation level via activating A1 receptor, to protect neurons in ischemia-reperfusion injury

Cytochrome P450 promiscuity leads to a bifurcating biosynthetic pathway for tanshinones

Cytochromes P450 (CYPs) play key role in generating the structural diversity of terpenoids, the largest group of plant natural products. However, functional characterization of CYPs has been challenging because of the expansive families found in plant genomes, diverse reactivity and inaccessibility of their substrates and products. • Here we present the characterization of two CYPs, CYP76AH3 and CYP76AK1, that act sequentially to form a bifurcating pathway for the biosynthesis of tanshinones, the oxygenated diterpenoids from the Chinese medicinal plant Danshen. • These CYPs had similar transcription profiles to that of the known gene responsible for tanshinone production in elicited Danshen hairy roots. Biochemical and RNA interference studies demonstrated that both CYPs are promiscuous. CYP76AH3 oxidizes ferruginol at two different carbon centers, and CYP76AK1 hydroxylates C-20 of two of the resulting intermediates. Together, these convert ferruginol into 11,20-dihydroxy ferruginol and 11,20-dihydroxy sugiol en route to tanshinones. Moreover, we demonstrate the utility of these CYPs by engineering yeast for heterologous production of six oxygenated diterpenoids, which in turn enabled structural characterization of three novel compounds produced by CYP-mediated oxidation. • Our results highlight the incorporation of multiple CYPs in diterpenoids metabolic engineering, and a continuing trend of CYPs promiscuity generating complex networks in terpenoid biosynthesis.This is the peer reviewed version of the following article: Guo, J., Ma, X., Cai, Y., Ma, Y., Zhan, Z., Zhou, Y. J., Liu, W., Guan, M., Yang, J., Cui, G., Kang, L., Yang, L., Shen, Y., Tang, J., Lin, H., Ma, X., Jin, B., Liu, Z., Peters, R. J., Zhao, Z. K. and Huang, L. (2016), Cytochrome P450 promiscuity leads to a bifurcating biosynthetic pathway for tanshinones. New Phytol, 210: 525–534, which has been published in final form at doi:10.1111/nph.13790. This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving.</p

Cytochrome P450 promiscuity leads to a bifurcating biosynthetic pathway for tanshinones

Cytochromes P450 (CYPs) play a key role in generating the structural diversity of terpenoids, the largest group of plant natural products. However, functional characterization of CYPs has been challenging because of the expansive families found in plant genomes, diverse reactivity and inaccessibility of their substrates and products. Here we present the characterization of two CYPs, CYP76AH3 and CYP76AK1, which act sequentially to form a bifurcating pathway for the biosynthesis of tanshinones, the oxygenated diterpenoids from the Chinese medicinal plant Danshen (Salvia miltiorrhiza). These CYPs had similar transcription profiles to that of the known gene responsible for tanshinone production in elicited Danshen hairy roots. Biochemical and RNA interference studies demonstrated that both CYPs are promiscuous. CYP76AH3 oxidizes ferruginol at two different carbon centers, and CYP76AK1 hydroxylates C-20 of two of the resulting intermediates. Together, these convert ferruginol into 11,20-dihydroxy ferruginol and 11,20-dihydroxy sugiol en route to tanshinones. Moreover, we demonstrated the utility of these CYPs by engineering yeast for heterologous production of six oxygenated diterpenoids, which in turn enabled structural characterization of three novel compounds produced by CYP-mediated oxidation. Our results highlight the incorporation of multiple CYPs into diterpenoid metabolic engineering, and a continuing trend of CYP promiscuity generating complex networks in terpenoid biosynthesis