2,772 research outputs found
Mechanistic insights into a BINOL-derived phosphoric acid-catalyzed asymmetric Pictet-Spengler reaction.
The reaction of tryptamine and (2-oxocyclohexyl)acetic acid can be catalyzed by 3,3'-bis(triphenylsilyl)-1,1'-bi-2-naphthol phosphoric acid to give an asymmetric β-carboline. This reaction was first studied by Holloway et al. ( Org. Lett. 2010 , 12 , 4720 - 4723 ), but their mechanistic work did not explain the high stereoselectivity achieved. This study uses density functional theory and hybrid quantum mechanics/molecular mechanics calculations to investigate this reaction and provide a model to explain its outcome. The step leading to diastereo- and enantioselectivity is an asymmetric Pictet-Spengler reaction involving an N-acyliminium ion bound to the catalyst in a bidentate fashion. This interaction occurs via hydrogen bonds between the two terminal oxygen atoms of the catalyst phosphate group and the hydrogen atoms at N and C2 of the substrate indole group. These bonds hold the transition structure rigidly and thus allow the catalyst triphenylsilyl groups to influence the enantioselectivity.We thank Girton College, Cambridge (research fellowship to M.N.G.), the EPSRC (studentship to M.N.G.), and Unilever for support.The is the final published version. It first appeared at http://pubs.acs.org/doi/abs/10.1021/jo5028134
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The CMIP5 model and simulation documentation: a new standard for climate modelling metadata
A four gene signature of chromosome instability (CIN4) predicts for benefit from taxanes in the NCIC-CTG MA21 clinical trial.
Recent evidence demonstrated CIN4 as a predictive marker of anthracycline benefit in early breast cancer. An analysis of the NCIC CTG MA.21 clinical trial was performed to test the role of existing CIN gene expression signatures as prognostic and predictive markers in the context of taxane based chemotherapy.RNA was extracted from patients in cyclophosphamide, epirubicin and flurouracil (CEF) and epirubicin, cyclophosphamide and paclitaxel (EC/T) arms of the NCIC CTG MA.21 trial and analysed using NanoString technology.After multivariate analysis both high CIN25 and CIN70 score was significantly associated with an increased in RFS (HR 1.76, 95%CI 1.07-2.86, p=0.0018 and HR 1.59, 95%CI 1.12-2.25, p=0.0096 respectively). Patients whose tumours had low CIN4 gene expression scores were associated with an increase in RFS (HR: 0.64, 95% CI 0.39-1.03, p=0.06) when treated with EC/T compared to patients treated with CEF.In conclusion we have demonstrated CIN25 and CIN70 as prognostic markers in breast cancer and that CIN4 is a potential predictive maker of benefit from taxane treatment
United States Experience with Music the Arts Curriculum and Implications for Teacher Education
For many years, when music was integrated into the curriculum it was done by the primary classroom teacher weaving music throughout the school experiences of the children. With careful planning, social studies, spelling, maths, art, physical education, and other curricular components were enhanced by having music contribute to broader understanding of them, and by helping to make experiences within those curricular components more interesting. The children would have opportunities to sing songs of the countries being studied in social studies, to learn spelling words and number combinations through chants or songs, to develop works of art while listening to music, to develop physically while doing movement activities in time to music, and so on
LAF1, a MYB transcription activator for phytochrome A signaling
The photoreceptor phytochrome (phy) A has a well-defined role in regulating gene expression in response to specific light signals. Here, we describe a new Arabidopsis mutant, laf1 (long after far-red light 1) that has an elongated hypocotyl specifically under far-red light. Gene expression studies showed that laf1 has reduced responsiveness to continuous far-red light but retains wild-type responses to other light wavelengths. As far-red light is only perceived by phyA, our results suggest that LAF1 is specifically involved in phyA signal transduction. Further analyses revealed that laf1 is affected in a subset of phyA-dependent responses and the phenotype is more severe at low far-red fluence rates. LAF1 encodes a nuclear protein with strong homology with the R2R3-MYB family of DNA-binding proteins. Experiments using yeast cells identified a transactivation domain in the C-terminal portion of the protein. LAF1 is constitutively targeted to the nucleus by signals in its N-terminal portion, and the full-length protein accumulates in distinct nuclear speckles. This accumulation in speckles is abolished by a point mutation in a lysine residue (K258R), which might serve as a modification site by a small ubiquitin-like protein (SUMO)
Letter from Lois N. Sloane, National Licensing Director for MGM/UA, to Geraldine Ferraro
Congratulatory letter from Lois N. Sloane, National Licensing Director for MGM/UA, to Geraldine Ferraro. Includes data entry sheet.https://ir.lawnet.fordham.edu/vice_presidential_campaign_correspondence_1984_new_york/1289/thumbnail.jp
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Omega-3 polyunsaturated fatty acids preserve retinal function in type 2 diabetic mice
Objective: Diabetic retinopathy (DR) is associated with hyperglycemia-driven microvascular pathology and neuronal compromise in the retina. However, DR is also linked to dyslipidemia. As omega-3 (ω-3) polyunsaturated fatty acids (PUFAs) are protective in proliferative retinopathy, we investigated the capacity of ω-3PUFAs to preserve retinal function in a mouse model of type 2 diabetes mellitus (T2DM). Design: Male leptin-receptor-deficient (db/db) mice were maintained for 22 weeks (4 weeks–26 weeks of life) on calorically and compositionally matched diets, except for 2% enrichment in either ω-3 or ω-6PUFAs. Visual function was assessed at 9, 14 and 26 weeks by electroretinography. Retinal capillary and neuronal integrity, as well as glucose challenge responses, were assessed on each diet. Results: The ω-3PUFA diet significantly preserved retinal function in the mouse model of T2DM to levels similar to those observed in nondiabetic control mice on normal chow. Conversely, retinal function gradually deteriorated in db/db mice on a ω-6PUFA-rich diet. There was also an enhanced ability of ω-3PUFA-fed mice to respond to glucose challenge. The protection of visual function appeared to be independent of cytoprotective or anti-inflammatory effects of ω-3PUFAs. Conclusion: This study identifies beneficial effects of dietary ω-3PUFAs on visual function in T2DM. The data are consistent with dyslipidemia negatively impacting retinal function. As ω-3PUFA lipid dietary interventions are readily available, safe and inexpensive, increasing ω-3PUFA intake in diabetic patients may slow the progression of vision loss in T2DM
Pregnant Women’s Malaria Knowledge in Ebonyi State, South-East Nigeria
The study aimed at investigating knowledge of malaria among pregnant women in Ebonyi state, South-east Nigeria. The cross-sectional survey research design was adopted in the study. Stratified sampling technique was used in selecting 504 pregnant women attending antenatal clinic in 12 hospitals in the state. A face validated, self constructed questionnaire which was subjected to a reliability test using Kuder Richardson Formula 20 (K-R 20) yielded a reliability value of 0.94. Percentages were used for analysis for the purpose of describing the data and chi-square statistic was used for the purpose of testing hypotheses. Results of the study showed that pregnant women had high (64.90%) level of knowledge regarding malaria. However, a good proportion of the pregnant women specifically had misconception about the cause of malaria and its mode of transmission. The pregnant women significantly differed in the knowledge of malaria with those having post secondary education (70.70%) showing better knowledge, followed by those with secondary (66.10%), primary (63.09%) and non-formal (55.70%) education. Location of residence was significantly associated with knowledge of malaria with those living in the urban area demonstrating better knowledge than those in the rural area. The high level of malaria knowledge among the women should be sustained through constant malaria health education interventions for pregnant women in the state. Intervention efforts should focus on rural pregnant women and formulated to accommodate the less educated members of this group as well as address misconceptions about the cause of malaria. Keywords: Malaria, Knowledge, Pregnant women, Ebonyi stat
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