300 research outputs found

    Prognostic significance of right ventricular ejection fraction for persistent complex ventricular arrhythmias and/or sudden cardiac death after first myocardial infarction: Relation to infarct location, size and left ventricular function

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    To assess the prognostic significance of right ventricular dysfunction after a first myocardial infarction for complex ventricular arrhythmias and or sudden cardiac death in relation to infarct location, size and left ventricular function, a series of 127 consecutive patients was prospectively studied and followed up for one year. Prior to hospital discharge, a 24-hour electrocardiographic recording and radionuclide angiocardiography were performed. Right ventricular ejection fraction was related to inferior infarct location and size (r = 0.45, P 0.40 vs. ≤ 0.40 showed that presence of complex ventricular ectopic activity and/or sudden cardiac death after myocardial infarction was related not only to left, but also independently to right ventricular dysfunction. These results imply a significant prognostic contribution of right ventricular dysfunction to the occurrence of severe ventricular arrhythmias and/or sudden cardiac death after myocardial infarction independent of and additive to left ventricular dysfunctio

    Depriving Mice of Sleep also Deprives of Food.

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    Both sleep-wake behavior and circadian rhythms are tightly coupled to energy metabolism and food intake. Altered feeding times in mice are known to entrain clock gene rhythms in the brain and liver, and sleep-deprived humans tend to eat more and gain weight. Previous observations in mice showing that sleep deprivation (SD) changes clock gene expression might thus relate to altered food intake, and not to the loss of sleep per se. Whether SD affects food intake in the mouse and how this might affect clock gene expression is, however, unknown. We therefore quantified (i) the cortical expression of the clock genes Per1, Per2, Dbp, and Cry1 in mice that had access to food or not during a 6 h SD, and (ii) food intake during baseline, SD, and recovery sleep. We found that food deprivation did not modify the SD-incurred clock gene changes in the cortex. Moreover, we discovered that although food intake during SD did not differ from the baseline, mice lost weight and increased food intake during subsequent recovery. We conclude that SD is associated with food deprivation and that the resulting energy deficit might contribute to the effects of SD that are commonly interpreted as a response to sleep loss

    Clock-dependent chromatin topology modulates circadian transcription and behavior.

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    The circadian clock in animals orchestrates widespread oscillatory gene expression programs, which underlie 24-h rhythms in behavior and physiology. Several studies have shown the possible roles of transcription factors and chromatin marks in controlling cyclic gene expression. However, how daily active enhancers modulate rhythmic gene transcription in mammalian tissues is not known. Using circular chromosome conformation capture (4C) combined with sequencing (4C-seq), we discovered oscillatory promoter-enhancer interactions along the 24-h cycle in the mouse liver and kidney. Rhythms in chromatin interactions were abolished in arrhythmic <i>Bmal1</i> knockout mice. Deleting a contacted intronic enhancer element in the <i>Cryptochrome 1</i> ( <i>Cry1</i> ) gene was sufficient to compromise the rhythmic chromatin contacts in tissues. Moreover, the deletion reduced the daily dynamics of <i>Cry1</i> transcriptional burst frequency and, remarkably, shortened the circadian period of locomotor activity rhythms. Our results establish oscillating and clock-controlled promoter-enhancer looping as a regulatory layer underlying circadian transcription and behavior

    Sraffa and Leontief Revisited: Mathematical Methods and Models of a Circular Economy

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    The new book SRAFFA AND LEONTIEF REVISITED: Mathematical methods and models of a circular economy is dedicated to Wassiliy Leontief’s concepts of Input-Output Analysis and to the algebraic properties of Piero Sraffa's seminal models described consequently by matrix algebra and the Perron-Frobenius Theorem. The academic editor Walter de Gruyter-Oldenbourg, has published this monography in January 2020 in English language.Мета роботи – дати інформацію про нову книгу «Повернення до Сраффи та Леонтьєва. Математичні методи і моделі кругової економіки». Ця монографія була видана в січні 2020 англійською мовою німецьким науковим видавництвом Вальтер де Гройтер (Walter de Gruyter-Oldenbourg).Цель работы – дать представление о новой книге «Возвращение к Сраффе и Леонтьеву. Математические методы и модели круговой экономики». Эта монография была издана в январе 2020 на английском языке немецким научным издательством Вальтер де Гройтер (Walter de Gruyter-Oldenbourg)

    Coherent, time-shifted patterns of microstructural plasticity during motor-skill learning

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    Motor skill learning relies on neural plasticity in the motor and limbic systems. However, the spatial and temporal characteristics of these changes-and their microstructural underpinnings-remain unclear. Eighteen healthy males received 1 hour of training in a computer-based motion game, 4 times a week, for 4 consecutive weeks, while 14 untrained participants underwent scanning only. Performance improvements were observed in all trained participants. Serial myelin- and iron-sensitive multiparametric mapping at 3T during this period of intensive motor skill acquisition revealed temporally and spatially distributed, performance-related microstructural changes in the grey and white matter across a corticospinal-cerebellar-hippocampal circuit. Analysis of the trajectory of these transient changes suggested time-shifted cascades of plasticity from the dominant sensorimotor system to the contralateral hippocampus. In the cranial corticospinal tracts, changes in myelin-sensitive metrics during training in the posterior limb of the internal capsule were of greater magnitude in those who trained their upper limbs vs. lower limb trainees. Motor skill learning is associated with waves of grey and white matter plasticity, across a broad sensorimotor network

    Coherent, time-shifted patterns of microstructural plasticity during motor-skill learning

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    Motor skill learning relies on neural plasticity in the motor and limbic systems. However, the spatial and temporal characteristics of these changes-and their microstructural underpinnings-remain unclear. Eighteen healthy males received 1 h of training in a computer-based motion game, 4 times a week, for 4 consecutive weeks, while 14 untrained participants underwent scanning only. Performance improvements were observed in all trained participants. Serial myelin- and iron-sensitive multiparametric mapping at 3T during this period of intensive motor skill acquisition revealed temporally and spatially distributed, performance-related microstructural changes in the grey and white matter across a corticospinal-cerebellar-hippocampal circuit. Analysis of the trajectory of these transient changes suggested time-shifted cascades of plasticity from the dominant sensorimotor system to the contralateral hippocampus. In the cranial corticospinal tracts, changes in myelin-sensitive metrics during training in the posterior limb of the internal capsule were of greater magnitude in those who trained their upper limbs vs. lower limb trainees. Motor skill learning is associated with waves of grey and white matter plasticity, across a broad sensorimotor network

    Breath acetone as a marker of energy balance: an exploratory study in healthy humans.

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    An exploratory study was performed on eight healthy volunteers to assess how short-term changes in energy balance and dietary carbohydrate content impact breath acetone concentrations. Participants were studied on three occasions: on each occasion, they remained fasted and in resting conditions during the first 2 h to assess basal breath acetone and blood beta-hydroxybutyrate (BOHB). During the next 6 h, they remained fasted on one occasion (F), or were fed hourly high carbohydrate (HC) or low-carbohydrate (LC) meals to induce a positive energy balance on the other two occasions. They remained in resting conditions during 4 h, then performed a 2-hour low intensity exercise (25 W) inducing a negative energy balance. In resting conditions, breath acetone and blood BOHB concentrations increased progressively compared to basal values in F, but decreased and remained low throughout the test in HC. With LC, breath acetone increased progressively, while blood BOHB decreased. This exploratory study indicates that breath acetone reliably detects a stimulation of ketogenesis during a short-term fast. It also suggests that LC and HC differentially impact BOHB and acetone production and utilization, and reveals possible limitations to the use of breath acetone as a marker of energy balance

    Turning a Killing Mechanism into an Adhesion and Antifouling Advantage

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    Mild and universal methods to introduce functionality in polymeric surfaces remain a challenge. Herein, a bacterial killing mechanism based on amphiphilic antimicrobial peptides is turned into an adhesion advantage. Surface activity (surfactant) of the antimicrobial liquid chromatography peak I (LCI) peptide is exploited to achieve irreversible binding of a protein–polymer hybrid to surfaces via physical interactions. The protein–polymer hybrid consists of two blocks, a surface‐affine block (LCI) and a functional block to prevent protein fouling on surfaces by grafting antifouling polymers via single electron transfer‐living radical polymerization (SET‐LRP). The mild conditions of SET‐LRP of N‐2‐hydroxy propyl methacrylamide (HPMA) and carboxybetaine methacrylamide (CBMAA) preserve the secondary structure of the fusion protein. Adsorption kinetics and grafting densities are assessed using surface plasmon resonance and ellipsometry on model gold surfaces, while the functionalization of a range of artificial and natural surfaces, including teeth, is directly observed by confocal microscopy. Notably, the fusion protein modified with poly(HPMA) completely prevents the fouling from human blood plasma and thereby exhibits a resistance to protein fouling that is comparable to the best grafted‐from polymer brushes. This, combined with their simple application on a large variety of materials, highlights the universal and scalable character of the antifouling concept
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