72 research outputs found

    Molecular structures and vibrations of neutral and anionic CuOx (x = 1-3,6) clusters

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    We report equilibrium geometric structures of CuO2, CuO3, CuO6, and CuO clusters obtained by an all-electron linear combination of atomic orbitals scheme within the density-functional theory with generalized gradient approximation to describe the exchange-correlation effects. The vibrational stability of all clusters is examined on the basis of the vibrational frequencies. A structure with Cs symmetry is found to be the lowest-energy structure for CuO2, while a -shaped structure with C2v symmetry is the most stable structure for CuO3. For the larger CuO6 and CuO clusters, several competitive structures exist with structures containing ozonide units being higher in energy than those with O2 units. The infrared and Raman spectra are calculated for the stable optimal geometries. ~Comment: Uses Revtex4, (Better quality figures can be obtained from authors

    Multiple populations in globular clusters. Lessons learned from the Milky Way globular clusters

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    Recent progress in studies of globular clusters has shown that they are not simple stellar populations, being rather made of multiple generations. Evidence stems both from photometry and spectroscopy. A new paradigm is then arising for the formation of massive star clusters, which includes several episodes of star formation. While this provides an explanation for several features of globular clusters, including the second parameter problem, it also opens new perspectives about the relation between globular clusters and the halo of our Galaxy, and by extension of all populations with a high specific frequency of globular clusters, such as, e.g., giant elliptical galaxies. We review progress in this area, focusing on the most recent studies. Several points remain to be properly understood, in particular those concerning the nature of the polluters producing the abundance pattern in the clusters and the typical timescale, the range of cluster masses where this phenomenon is active, and the relation between globular clusters and other satellites of our Galaxy.Comment: In press (The Astronomy and Astrophysics Review

    Effectiveness and cost-effectiveness of transmural collaborative care with consultation letter (TCCCL) and duloxetine for major depressive disorder (MDD) and (sub)chronic pain in collaboration with primary care: design of a randomized placebo-controlled multi-Centre trial: TCC:PAINDIP

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    __Abstract__ Background: The comorbidity of pain and depression is associated with high disease burden for patients in terms of disability, wellbeing, and use of medical care. Patients with major and minor depression often present themselves with pain to a general practitioner and recognition of depression in such cases is low, but evolving. Also, physical symptoms, including pain, in major depressive disorder, predict a poorer response to treatment. A multi-faceted, patient-tailored treatment programme, like collaborative care, is promising. However, treatment of chronic pain conditions in depressive patients has, so far, received limited attention in research. Cost effectiveness of an integrated approach of pain in depressed patients has not been studied. This article describes the aims and design of a study to evaluate effects and costs of collaborative care with the antidepressant duloxetine for patients with pain symptoms and a depressive disorder, compared to collaborative care with placebo and compared to duloxetine alone

    Synthesis of the elements in stars: forty years of progress

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    Venous hemodynamics in neurological disorders: an analytical review with hydrodynamic analysis.

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    Venous abnormalities contribute to the pathophysiology of several neurological conditions. This paper reviews the literature regarding venous abnormalities in multiple sclerosis (MS), leukoaraiosis, and normal-pressure hydrocephalus (NPH). The review is supplemented with hydrodynamic analysis to assess the effects on cerebrospinal fluid (CSF) dynamics and cerebral blood flow (CBF) of venous hypertension in general, and chronic cerebrospinal venous insufficiency (CCSVI) in particular.CCSVI-like venous anomalies seem unlikely to account for reduced CBF in patients with MS, thus other mechanisms must be at work, which increase the hydraulic resistance of the cerebral vascular bed in MS. Similarly, hydrodynamic changes appear to be responsible for reduced CBF in leukoaraiosis. The hydrodynamic properties of the periventricular veins make these vessels particularly vulnerable to ischemia and plaque formation.Venous hypertension in the dural sinuses can alter intracranial compliance. Consequently, venous hypertension may change the CSF dynamics, affecting the intracranial windkessel mechanism. MS and NPH appear to share some similar characteristics, with both conditions exhibiting increased CSF pulsatility in the aqueduct of Sylvius.CCSVI appears to be a real phenomenon associated with MS, which causes venous hypertension in the dural sinuses. However, the role of CCSVI in the pathophysiology of MS remains unclear

    Behavioral Modifications Related to Consumption of a “Soft” Adaptogen, Bee Honey, by Rats

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    Modifications of neurobehavioral activities related to single episodes of consumption of different doses of bee honey were examined in rats under conditions of the hole-board (HB) test (to evaluate the level of anxiety) and open-field (OF) test (where the intensities of locomotion, rearing, and grooming were measured). Animals of all subgroups had free access to normal saline, while rats of the three experimental subgroups consumed bee honey in the doses of 0.5, 1.0, and 2.0 g per 1 kg body mass (in the form of 10, 20, and 40% solutions, respectively). Among the doses tested, only higher ones induced considerable c hanges in the behavioral indices. The highest dose (2.0 g/kg) provided a more than twofold increase in the number of examined holes in the HB test; in the OF test, it also increased the numbers of crossed squares, rearings and grooming episodes by 30, 37, and 164%, respectively. Thus, our experiments demonstrated rather significant ability of the natural product tested to relieve anxiety and intensify motor, research/orientational, and grooming aspects of behavior even upon single acts of consumption. Possible neurophysiological mechanisms underlying the behavioral modifications observed are discussed.Модифікації нейроповедінкової активності, пов’язані з поодинокими епізодами споживання бджолиного меду в різних дозах, були вивчені у щурів в умовах норкового тесту (визначення рівня тривожності) і тесту відкритого поля (вимірювання кількості епізодів локомоції, вертикальних стійок і грумінгу). Тварини контрольних підгруп мали вільний доступ до фізіологічного розчину, тоді як щури трьох експериментальних підгруп споживали мед у дозах 0.5, 0.1 та 2.0 г з розрахунку на 1 кг маси тіла (у вигляді 10, 20 й 40 %-вого розчинів відповідно). Значні зміни поведінкових показників виникали тільки при вищих тестованих дозах. Максимальна доза (2.0 г/кг) зумовлювала більше ніж дворазове збільшення кількості досліджених отворів у норковому тесті; в умовах тесту відкритого поля при такій дозі також збільшувалася кількість пересічень щурами квадратів, вертикальних стійок та епізодів грумінгу відповідно на 30, 37 і 164 %. Отже, результати наших експериментів показали, що тестований натуральний продукт (бджолиний мед) виявляє значну здатність знижувати рівень тривожності та посилювати моторні, дослідницькі/орієнтаційні та грумінгові аспекти поведінки навіть у разі поодиноких актів його споживання. Обговорюються можливі нейрофізіологічні механізми, що лежать в основі поведінкових модифікацій, спостережуваних в експерименті
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