Dual role of benzophenone enables a fast and scalable C-4 selective alkylation of pyridines in flow

The efficient C-4 selective modification of pyridines is a major challenge for the synthetic community. Current strategies are plagued with at least one drawback regarding functional group-tolerant electronic activation of the heteroarene, mild generation of the required alkyl radicals, regioselectivity, safety and/or scalability. Herein, we describe a fast, safe and scalable flow process which allows preparation of said C-4 alkylated pyridines. The process involves a photochemical hydrogen atom transfer (HAT) event to generate the carbon-centered radicals needed to alkylate the C-2 blocked pyridine. In a two-step streamlined flow process, this light-mediated alkylation step is combined with a nearly instantaneous inline removal of the blocking group. Notably, cheap benzophenone plays a dual role in the pyridine alkylation mechanism by activating the hydrocarbon feedstock reagents via a HAT mechanism, and by acting as a benign, terminal oxidant. The key role of benzophenone in the operative reaction mechanism has also been revealed through a combination of experimental and computational studies

A small universe after all?

The cosmic microwave background radiation allows us to measure both the geometry and topology of the universe. It has been argued that the COBE-DMR data already rule out models that are multiply connected on scales smaller than the particle horizon. Here we show the opposite is true: compact (small) hyperbolic universes are favoured over their infinite counterparts. For a density parameter of Omega_o=0.3, the compact models are a better fit to COBE-DMR (relative likelihood ~20) and the large-scale structure data (sigma_8 increases by ~25%).Comment: 4 pages, RevTeX, 7 Figure

Simulating Cosmic Microwave Background maps in multi-connected spaces

This article describes the computation of cosmic microwave background anisotropies in a universe with multi-connected spatial sections and focuses on the implementation of the topology in standard CMB computer codes. The key ingredient is the computation of the eigenmodes of the Laplacian with boundary conditions compatible with multi-connected space topology. The correlators of the coefficients of the decomposition of the temperature fluctuation in spherical harmonics are computed and examples are given for spatially flat spaces and one family of spherical spaces, namely the lens spaces. Under the hypothesis of Gaussian initial conditions, these correlators encode all the topological information of the CMB and suffice to simulate CMB maps.Comment: 33 pages, 55 figures, submitted to PRD. Higher resolution figures available on deman

Modelling the electric field applied to a tokamak

The vector potential for the Ohmic heating coil system of a tokamak is obtained in semi-analytical form. Comparison is made to the potential of a simple, finite solenoid. In the quasi-static limit, the time rate of change of the potential determines the induced electromotive force through the Maxwell-Lodge effect. Discussion of the gauge constraint is included.Comment: 13 pages, 7 figures, final versio

Cosmic microwave background anisotropies in multi-connected flat spaces

This article investigates the signature of the seventeen multi-connected flat spaces in cosmic microwave background (CMB) maps. For each such space it recalls a fundamental domain and a set of generating matrices, and then goes on to find an orthonormal basis for the set of eigenmodes of the Laplace operator on that space. The basis eigenmodes are expressed as linear combinations of eigenmodes of the simply connected Euclidean space. A preceding work, which provides a general method for implementing multi-connected topologies in standard CMB codes, is then applied to simulate CMB maps and angular power spectra for each space. Unlike in the 3-torus, the results in most multi-connected flat spaces depend on the location of the observer. This effect is discussed in detail. In particular, it is shown that the correlated circles on a CMB map are generically not back-to-back, so that negative search of back-to-back circles in the WMAP data does not exclude a vast majority of flat or nearly flat topologies.Comment: 33 pages, 19 figures, 1 table. Submitted to PR

ALTERAÇÕES MORFOLÓGICAS DE LEUCÓCITOS E TROMBÓCITOS SANGUÍNEOS EM Piaractus mesopotamicus DURANTE A SEPSE

Sepsis is defined as organ dysfunction with high mortality. During this process, the hematological system plays a critical role. Thus, the work aimed to analyze the morphological changes in the leukogram and thrombogram by the indirect method in the course of sepsis in Piaractus mesopotamicus. For this, 98 pacus were used, divided into two groups, one received 0.5 ml of sterile 0.65% sodium chloride solution (control) and the other received the same volume containing the bacterial inoculum (1.8 x 108 CFU/ml – challenge). To assess such changes in the evolution of sepsis, blood samples were collected from fish 1, 3, 6 and 9 hours after inoculation and in the control group (n = 10). One aliquot of the blood was used for blood culture and another for determining the number of leukocytes and thrombotics by the indirect method and the evaluation of morphological changes in blood extensions. Aeromonosis was confirmed by positive blood culture in all samples from the challenged groups. The leukogram analysis showed a significant increase (p <0.05) of leukocytes in the later times, 9 and 6 HPI in relation to the control group. Differential analysis showed leukopenia (p <0.05; 3 HPI) and consumption of thrombocytes. It was found that with the increase of the infection the septicemic pacus develops a picture of granulocytosis and monocytosis (p <0.05). It was concluded that inoculation with A. hydrophila induced sepsis with positive blood culture with leukocytosis in the challenged pacus and caused an intense change in the leukocyte and thrombotic morphology.KEYWORDS: Hemoculture, Leukogram, Morphology, Aeromonas hydrophila, Teleosts.La sepsis se define como disfunción orgánica con alta mortalidad. Durante este proceso, el sistema hematológico juega un papel crítico. Por lo tanto, el trabajo tuvo como objetivo analizar los cambios morfológicos en el leucograma y el trombograma por el método indirecto en el curso de la sepsis en Piaractus mesopotamicus. Para esto, se utilizaron 98 pacus, divididos en dos grupos, uno recibió 0,5 ml de solución estéril de cloruro de sodio al 0,65% (control) y el otro recibió el mismo volumen que contenía el inóculo bacteriano (1,8 x 108 UFC / ml - desafío). Para evaluar dichos cambios en la evolución de la sepsis, se recogieron muestras de sangre de peces 1, 3, 6 y 9 horas después de la inoculación y en el grupo de control (n = 10). Una parte alícuota de la sangre se usó para el hemocultivo y otra para determinar el número de leucocitos y trombóticos mediante el método indirecto y la evaluación de los cambios morfológicos en las extensiones de sangre. La aeromonosis se confirmó por hemocultivo positivo en todas las muestras de los grupos desafiados. El análisis de leucogramas mostró un aumento significativo (p <0.05) de leucocitos en los últimos tiempos, 9 y 6 HPI en relación con el grupo de control. El análisis diferencial mostró leucopenia (p <0.05; 3 HPI) y consumo de trombocitos. Se encontró que con el aumento de la infección, el pacus septicémico desarrolla una imagen de granulocitosis y monocitosis (p <0.05). Se concluyó que la inoculación con A. hydrophila indujo sepsis con hemocultivo positivo con leucocitosis en pacus desafiado y causa un cambio intenso en los leucocitos y la morfología trombóticaPALABRAS CLAVES Hemocultivo, Leucograma, Morfología, Aeromonas hydrophila, Teleósteos.A sepse é definida como disfunção orgânica com alta mortalidade. Durante esse processo o sistema hematológico desempenha um papel crítico. Assim, o trabalho objetivou analisar as alterações morfológicas no leucograma e no trombograma pelo método indireto no curso da sepse em Piaractus mesopotamicus. Para tanto, foram utilizados 98 pacus, divididos em dois grupos, um deles recebeu 0,5 ml de solução de cloreto de sódio esterilizada a 0,65% (controle) e outro recebeu o mesmo volume contendo o inoculo bacteriano (18 x 108 CFU/ml – desafio). Para avaliar tais alterações na evolução da sepse foram realizadas coletas de sangue dos peixes 1, 3, 6 e 9 horas após inoculação e no grupo controle (n=10). Uma alíquota do sangue foi destina a hemocultura e outra na determinação do número de leucócitos e de trombóticos pelo método indireto e a avaliação das alterações morfológicas nas extensões sanguíneas. A aeromonose foi confirmada pela hemocultura positiva em todas as amostras dos grupos desafiados. A análise do leucograma demonstrou aumento significativa (p<0,05) dos leucócitos nos tempos mais tardios, 9 e 6 HPI em relação ao grupo controle. Da análise diferencial observou-se leucopenia (p<0,05; 3 HPI) e consumo dos trombócitos. Verificou-se que com o aumento da infecção os pacus septicêmicos desenvolvem um quadro de granulocitose e monocitose (p<0,05). Concluiu-se que a inoculação com A. hydrophila induziu a sepse com hemocultura positiva com leucocitose nos pacus desafiados e causa intensa alteração na morfologia dos leucócitos e trombóticos.PALAVRAS-CHAVE: Hemocultura, Leucograma, Morfologia, Aeromonas hydrophila, Teleósteos