276 research outputs found

    Construction of Bicyclo[2.2.2]diazaoctane Alkaloids via Intermolecular [4+2] Cycloadditions

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    The synthesis of bicyclo[2.2.2]diazaoctane prenylated indole alkaloids, containing both syn and anti ring fusion, is described. More than 100 examples of alkaloids in this family have been isolated and show a variety of potent bioactivities. This strategy utilizes the convergent and atom–economic intermolecular hetero Diels–Alder cycloaddition to construct the bicyclic nucleus from electron–deficient dienophiles and an electron–rich pyrazinone diene. The regiochemical and stereochemical implications of this cyclization are investigated

    Generalized "Yoking-Proofs" and Inter-Tag Communication

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    Efforts in Natural Product Total Synthesis via Dearomatization of Functionalized Arenes: I. Tetrodotoxin and II. Veratrum Alkaloids

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    I. Efforts Towards the Total Synthesis of (–)-TetrodotoxinA masked ortho-benzoquinone was used in a highly diastereoselective acylnitroso hetero-Diels-Alder [4+2] cycloaddition to forge the fully substituted syn 1,4-aminocyclohexanol motif embedded in the complex bioactive natural product tetrodotoxin. Multiple advanced intermediates en route to the target molecule were prepared but efforts to complete the total synthesis were thwarted by difficulties in a late-stage ketone homologation or in guanidinylation of a neopentylic amine. II. Hydroxyphosphonate-Enabled Tandem Phosphono-Adler-Becker Oxidations/Hetero-Diels-Alder Cycloadditions: Progress Towards the Total Synthesis of TetrodotoxinA heretofore unknown phosphono-Adler-Becker oxidation of dialkoxyphosphinylsalicyl alcohols was performed in tandem with an acylnitroso hetero-Diel-Alder [4+2] cycloaddition to construct complex oxazinanes. This synthetic strategy enables the use of “salicylaldehyde diene” equivalents following phosphite extrusion to reveal an aldehyde. Efforts to assemble a functionalized arene that would intercept this chemistry en route to tetrodotoxin are also reported. III. De Novo Synthesis of the DEF Stereotriad Core of the Veratrum AlkaloidsA convergent approach towards the synthesis of the Veratrum alkaloids is presented. The alkaloid-like tricyclic core common to jervine and cyclopamine was stereoselectively and efficiently prepared from cheap and readily available reagents. By analogy to the biosynthetic aromatization of cyclopamine to veratramine, a two-directional bicyclization was achieved wherein a functionalized phenol used to generate the D ring.Doctor of Philosoph

    Binary Interval Search (BITS): A Scalable Algorithm for Counting Interval Intersections

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    Motivation: The comparison of diverse genomic datasets is fundamental to understanding genome biology. Researchers must explore many large datasets of genome intervals (e.g., genes, sequence alignments) to place their experimental results in a broader context and to make new discoveries. Relationships between genomic datasets are typically measured by identifying intervals that intersect: that is, they overlap and thus share a common genome interval. Given the continued advances in DNA sequencing technologies, efficient methods for measuring statistically significant relationships between many sets of genomic features is crucial for future discovery. Results: We introduce the Binary Interval Search (BITS) algorithm, a novel and scalable approach to interval set intersection. We demonstrate that BITS outperforms existing methods at counting interval intersections. Moreover, we show that BITS is intrinsically suited to parallel computing architectures such as Graphics Processing Units (GPUs) by illustrating its utility for efficient Monte-Carlo simulations measuring the significance of relationships between sets of genomic intervals

    Low Rates of Both Lipid-Lowering Therapy Use and Achievement of Low-Density Lipoprotein Cholesterol Targets in Individuals at High-Risk for Cardiovascular Disease across Europe

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    Aims To analyse the treatment and control of dyslipidaemia in patients at high and very high cardiovascular risk being treated for the primary prevention of cardiovascular disease (CVD) in Europe. Methods and Results Data were assessed from the European Study on Cardiovascular Risk Prevention and Management in Usual Daily Practice (EURIKA, ClinicalTrials.gov identifier: NCT00882336), which included a randomly sampled population of primary CVD prevention patients from 12 European countries (n = 7641). Patients’ 10-year risk of CVD-related mortality was calculated using the Systematic Coronary Risk Evaluation (SCORE) algorithm, identifying 5019 patients at high cardiovascular risk (SCORE 5% and/or receiving lipid-lowering therapy), and 2970 patients at very high cardiovascular risk (SCORE 10% or with diabetes mellitus). Among high-risk individuals, 65.3% were receiving lipid-lowering therapy, and 61.3% of treated patients had uncontrolled low-density lipoprotein cholesterol (LDL-C) levels ( 2.5 mmol/L). For very-high-risk patients (uncontrolled LDL-C levels defined as 1.8 mmol/L) these figures were 49.5% and 82.9%, respectively. Excess 10-year risk of CVD-related mortality (according to SCORE) attributable to lack of control of dyslipidaemia was estimated to be 0.72%and 1.61% among high-risk and very-high-risk patients, respectively. Among high-risk individuals with uncontrolled LDL-C levels, only 8.7% were receiving a high-intensity statin (atorvastatin 40 mg/day or rosuvastatin 20 mg/day). Among veryhigh- risk patients, this figure was 8.4%. Conclusions There is a considerable opportunity for improvement in rates of lipid-lowering therapy use and achievement of lipid-level targets in high-risk and very-high-risk patients being treated for primary CVD prevention in EuropeWriting support was provided by Oxford PharmaGenesis Ltd, Oxford, UK, and was funded by AstraZenec

    Multi-Scale Motility Amplitude Associated with Suicidal Thoughts in Major Depression

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    Major depression occurs at high prevalence in the general population, often starts in juvenile years, recurs over a lifetime, and is strongly associated with disability and suicide. Searches for biological markers in depression may have been hindered by assuming that depression is a unitary and relatively homogeneous disorder, mainly of mood, rather than addressing particular, clinically crucial features or diagnostic subtypes. Many studies have implicated quantitative alterations of motility rhythms in depressed human subjects. Since a candidate feature of great public-health significance is the unusually high risk of suicidal behavior in depressive disorders, we studied correlations between a measure (vulnerability index [VI]) derived from multi-scale characteristics of daily-motility rhythms in depressed subjects (n = 36) monitored with noninvasive, wrist-worn, electronic actigraphs and their self-assessed level of suicidal thinking operationalized as a wish to die. Patient-subjects had a stable clinical diagnosis of bipolar-I, bipolar-II, or unipolar major depression (n = 12 of each type). VI was associated inversely with suicidal thinking (r =  –0.61 with all subjects and r =  –0.73 with bipolar disorder subjects; both p<0.0001) and distinguished patients with bipolar versus unipolar major depression with a sensitivity of 91.7% and a specificity of 79.2%. VI may be a useful biomarker of characteristic features of major depression, contribute to differentiating bipolar and unipolar depression, and help to detect risk of suicide. An objective biomarker of suicide-risk could be advantageous when patients are unwilling or unable to share suicidal thinking with clinicians

    Expensive Egos: Narcissistic Males Have Higher Cortisol

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    Background: Narcissism is characterized by grandiosity, low empathy, and entitlement. There has been limited research regarding the hormonal correlates of narcissism, despite the potential health implications. This study examined the role of participant narcissism and sex on basal cortisol concentrations in an undergraduate population. Methods and Findings: Participants were 106 undergraduate students (79 females, 27 males, mean age 20.1 years) from one Midwestern and one Southwestern American university. Narcissism was assessed using the Narcissistic Personality Inventory, and basal cortisol concentrations were collected from saliva samples in a laboratory setting. Regression analyses examined the effect of narcissism and sex on cortisol (log). There were no sex differences in basal cortisol, F(1,97) =.20, p =.65, and narcissism scores, F(1,97) =.00, p =.99. Stepwise linear regression models of sex and narcissism and their interaction predicting cortisol concentrations showed no main effects when including covariates, but a significant interaction, b =.27, p =.04. Narcissism was not related to cortisol in females, but significantly predicted cortisol in males. Examining the effect of unhealthy versus healthy narcissism on cortisol found that unhealthy narcissism was marginally related to cortisol in females, b =.27, p =.06, but significantly predicted higher basal cortisol in males, b =.72, p =.01, even when controlling for potential confounds. No relationship was found between sex, narcissism, or their interaction on selfreported stress

    Girls' disruptive behavior and its relationship to family functioning: A review

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    Although a number of reviews of gender differences in disruptive behavior and parental socialization exist, we extend this literature by addressing the question of differential development among girls and by placing both disruptive behavior and parenting behavior in a developmental framework. Clarifying the heterogeneity of development in girls is important for developing and optimizing gender-specific prevention and treatment programs. In the current review, we describe the unique aspects of the development of disruptive behavior in girls and explore how the gender-specific development of disruptive behavior can be explained by family linked risk and protective processes. Based on this review, we formulate a gender-specific reciprocal model of the influence of social factors on the development of disruptive behavior in girls in order to steer further research and better inform prevention and treatment programs
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