2,570 research outputs found

    An \emph{ab initio} method for locating characteristic potential energy minima of liquids

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    It is possible in principle to probe the many--atom potential surface using density functional theory (DFT). This will allow us to apply DFT to the Hamiltonian formulation of atomic motion in monatomic liquids [\textit{Phys. Rev. E} {\bf 56}, 4179 (1997)]. For a monatomic system, analysis of the potential surface is facilitated by the random and symmetric classification of potential energy valleys. Since the random valleys are numerically dominant and uniform in their macroscopic potential properties, only a few quenches are necessary to establish these properties. Here we describe an efficient technique for doing this. Quenches are done from easily generated "stochastic" configurations, in which the nuclei are distributed uniformly within a constraint limiting the closeness of approach. For metallic Na with atomic pair potential interactions, it is shown that quenches from stochastic configurations and quenches from equilibrium liquid Molecular Dynamics (MD) configurations produce statistically identical distributions of the structural potential energy. Again for metallic Na, it is shown that DFT quenches from stochastic configurations provide the parameters which calibrate the Hamiltonian. A statistical mechanical analysis shows how the underlying potential properties can be extracted from the distributions found in quenches from stochastic configurations

    IAC 576 - cultivar de mandioca de mesa recomendada para Mato Grosso do Sul.

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    bitstream/item/24714/1/COT200380.pdfDocumento on-line

    A dietary supplement to reduce side effects of oral isotretinoin therapy in acne patients.

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    AIM: The purpose of the study was to analyze the potential capacity of a dietary supplement, based on gamma linolenic acid, vitamin E, vitamin C, beta-carotene, coenzyme Q10 and Vitis Vitifera, to reduce side effects, in particular the dry skin, erythema and desquamation, due to treatment with oral isotretinoin, and evaluate the ability of the product to increase adherence to therapy in patients with acne. METHODS: Forty-eight patients with nodular acne (32 females and 16 males) were randomly divided into 2 groups: 24 receveid isotretinoin therapy (20-30 mg/day) for 6 months associated to dietary supplement (twice a day), while the other 24 patients received only isotretinoin (20-30 mg/day) for 6 months. For all patients the degree of acne severity, through GAGS (Global Acne Grading System), the sebum production by Sebutape, the hydration by Corneometer and the erythema by Mexameter, were measured. We have also evaluated the adherence to treatment, asking to patients how many days a week they follow the therapy. RERSULTS: Patients treated with dietary supplement had lower side effects, with a less degree of erythema and dryness, and greater degree of hydration; a greater adherence to therapy was also reported. CONCLUSION: Thanks to antioxidant and moisturizing properties, the dietary supplement containing gamma linolenic acid, vitamin E, vitamin C, betacarotene, coenzyme Q10 and Vitis Vitifera, can be considered a useful supplement in the treatment and prevention of dry skin associated with the use of oral isotretinoin

    Learning impact of education during pulmonary rehabilitation program. An observational short-term cohort study

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    Background: Among the several components integrating a pulmonary rehabilitation (PR) course, education may contribute to the individual\u2019s recognition of symptoms and worsening of the disease. However, the specific gain of education is far to be clearly documented to the health care providers. Aim of our preliminary study was to assess the learning impact of educational sessions (ES) in Chronic Obstructive Pulmonary Disease (COPD) patients referred to standard PR.Methods: Six ES on 3 areas (Symptoms-Therapies, Aids, Mood) were applied during PR at our clinic. The learning effect was prospectively evaluated by a specific questionnaire (ESQ) in 285 COPD patients (age 69\ub18 years, FEV1 53\ub114 % pred), then grouped into those who have completed ES (Completers group, n=226) or who did not (mean 2\ub11 ES) (Control group, n=59). Total and partial ESQ scores, and PR outcomes (6-minute walking test-6MWD, effort-dyspnoea at Medical Research Council scale-MRC, and health-related quality of life scale-SGRQ) were assessed in a pre (T0) to post (Tend) design.Results: Similar improvement in PR outcomes was recorded in both groups at Tend, whereas ESQ total and partial scores significantly increased in Completers only (p<0.001). ESQ-Aids score improved to a greater extent in Completers than in Control (+0.60\ub11.03 vs +0.27\ub11.27 point respectively, p=0.036). A higher proportion of Completers improved above the median change of both ESQ total and aids scores (p<0.05).Conclusion: Attending educational sessions produces a specific short-term learning effect during rehabilitation of COPD patients

    Testing the nature of S0 galaxies using planetary nebula kinematics in NGC 1023

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    We investigate the manner in which lenticular galaxies are formed by studying their stellar kinematics: an S0 formed from a fading spiral galaxy should display similar cold outer disc kinematics to its progenitor, while an S0 formed in a minor merger should be more dominated by random motions. In a pilot study to attempt to distinguish between these scenarios, we have measured the planetary nebula (PN) kinematics of the nearby S0 system NGC 1023. Using the Planetary Nebula Spectrograph, we have detected and measured the line-of-sight velocities of 204 candidate PNe in the field of this galaxy. Out to intermediate radii, the system displays the kinematics of a normal rotationally-supported disc system. After correction of its rotational velocities for asymmetric drift, the galaxy lies just below the spiral galaxy Tully-Fisher relation, as one would expect for a fading system. However, at larger radii the kinematics undergo a gradual but major transition to random motion with little rotation. This transition does not seem to reflect a change in the viewing geometry or the presence of a distinct halo component, since the number counts of PNe follow the same simple exponential decline as the stellar continuum with the same projected disc ellipticity out to large radii. The galaxy's small companion, NGC 1023A, does not seem to be large enough to have caused the observed modification either. This combination of properties would seem to indicate a complex evolutionary history in either the transition to form an S0 or in the past life of the spiral galaxy from which the S0 formed. More data sets of this type from both spirals and S0s are needed in order to definitively determine the relationship between these types of system.Comment: Accepted for publication in MNRAS. Version with full resolution figure 1 can be found at http://www.nottingham.ac.uk/~ppzmrm/N1023_PNS.accepted.pd
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