Polymorphism, phonon dynamics and carrier-phonon coupling in pentacene

The crystal structure and phonon dynamics of pentacene is computed with the Quasi Harmonic Lattice Dynamics (QHLD) method, based on atom-atom potential. We show that two crystalline phases of pentacene exist, rather similar in thermodynamic stability and in molecular density. The two phases can be easily distinguished by Raman spectroscopy in the 10-100 cm-1 spectral region. We have not found any temperature induced phase transition, whereas a sluggish phase change to the denser phase is induced by pressure. The bandwidths of the two phases are slightly different. The charge carrier coupling to low-frequency phonons is calculated.Comment: 6 pages, 3 figures. Presented at ICFPAM-

Nitric Oxide Protects Neuroblastoma Cells from Apoptosis Induced by Serum Deprivation through cAMP-response Element-binding Protein (CREB) Activation

The transcription factor cAMP-response element-binding protein (CREB) mediates survival in many cells, including neurons. Recently, death of cerebellar granule neurons due to nitric oxide (NO) deprivation was shown to be accompanied by down-regulation of CREB activity (1). We now provide evidence that overproduction of endogenous NO or supplementation with exogenous NO renders SK-N-BE human neuroblastoma cells more resistant to apoptosis induced by serum deprivation. Parental cells underwent apoptosis after 24 h of serum deprivation, an outcome largely absent in clones overexpressing human neuronal nitric oxide synthase (nNOS). This protective effect was reversed by the inhibition of NOS itself or soluble guanylyl cyclase, pointing at cGMP as an intermediate effector of NO-mediated rescue. A slow-releasing NO donor protected parental cells to a significant extent, thus confirming the survival effect of NO. The impaired viability of serum-deprived parental cells was accompanied by a strong decrease of CREB phosphorylation and transcriptional activity, effects significantly attenuated in nNOS-overexpressing clones. To confirm the role of CREB in survival, the ectopic expression of CREB and/or protein kinase A largely counteracted serum deprivation-induced cell death of SK-N-BE cells, whereas transfection with a CREB negative mutant was ineffective. These experiments indicate that CREB activity is an important step for NO-mediated survival in neuronal cells

The Mediterranean Diet in the Prevention of Degenerative Chronic Diseases

Degenerative chronic diseases are a problem related to the aging phenomenon of industrialized countries due to the increase of risk factors and related comorbidity such as overweight, obesity, metabolic syndrome, diabetes, hypertension and hyperlipidemia with a consequent increased risk of cardiovascular disease (CVD) and cancer. Moreover, the significant reduction of physical activity in daily life and the huge growth in food availability have considerably increased the risk of such diseases. Particular attention should be paid to primary prevention by means of health strategies based on improvement in lifestyle intervention such as implementation of Mediterranean diet and promotion of physical activity programs. In this chapter, the protective effect of Mediterranean diet and the role of certain foods and/or their constituents are analyzed; the possible mechanisms by which Mediterranean diet is effective in the prevention of cardiovascular and other chronic diseases are presented, in particular the effects exerted by antioxidants, polyphenols, fibers, unsaturated fatty acids, and alcohol. The genetic revolution in the past decades has produced new fields of study where the interaction between foods, nutrients, and our genetic makeup is investigated. The relationship between nutrigenetics and nutrigenomics and the Mediterranean diet are the future area that research should discover

Solution equilibrium between two structures of Perylene-F ₂ TCNQ charge transfer co-crystals

We report on the solution growth of the two known structures of Perylene-F(2)TCNQ charge transfer complexes. The transformation accompanied by a marked morphological change from needle 1:1 to platelet 3:2 crystal structure is observed in the mother liquor. Lattice phonon Raman spectroscopy is used for an easy structure identification of the different morphologies before and after the process. X-ray and lattice phonons spectra of reference samples obtained by physical vapor transport is used to identify the two complexes. A fully spectroscopic analysis of the intramolecular Raman modes is presented to estimate the degree of ionicity, which is found to agree with the value previously reported

Accuracy of Predictive Equations for Estimating Resting Energy Expenditure in Obese Adolescents

ObjectiveTo compare resting energy expenditure (REE) measured by indirect calorimetry with REE predicted using different equations in obese adolescents.Study designWe recruited 264 obese patients (body mass index ranging from 30.0-70.0 kg/m2) between 14 and 18 years of age. Data were obtained comparing measured and predicted REE derived from published equations for normal weight and obese adolescents. The average differences between measured and predicted REE, as well as the accuracy at ±10% level, were evaluated.ResultsEvaluating the mean REE in 109 males (1938 ± 271 kcal/d) and 155 females (2569 ± 459 kcal/d), we found that the Lazzer equation in males had the smallest difference between measured and predicted REE; in females the Henry-1, Food and Agriculture Organization/World Health Organization/United Nations University, Schmelze, and Lazzer equations were the most accurate. The prediction accuracy was considered adequate within ±10%.ConclusionsREE predictive equations developed in obese patients and for specific age groups are more suitable than those for the general population. Inaccuracy of predicted REE could affect dietary prescription appropriateness and, consequently, dietary compliance in this age group

(Perylene)3-(TCNQF1)2: Yet Another Member in the Series of Perylene–TCNQFx Polymorphic Charge Transfer Crystals

The 3:2 Charge Transfer (CT) co-crystal (Perylene)3(TCNQF1)2 is grown by the Physical Vapor Transport (PVT) method, and characterized structurally and spectroscopically. Infrared analysis of the charge sensitive modes reveals a low degree of charge transfer (less than 0.1) between donor and acceptor molecules. The crystal is isostructural to the other 3:2 CT crystals formed by Perylene with TCNQF2 and TCNQF4, whereas such stoichiometry and packing is not known for the CT crystals with non-fluorinated TCNQ. The analysis of the isostructural family of 3:2 Perylene–TCNQFx (x = 1,2,4) co-crystal put in evidence the role of weak F…HC bonding in stabilizing this type of structure</jats:p

Phonons and structures of tetracene polymorphs at low temperature and high pressure

Crystals of tetracene have been studied by means of lattice phonon Raman spectroscopy as a function of temperature and pressure. Two different phases (polymorphs I and II) have been obtained, depending on sample preparation and history. Polymorph I is the most frequently grown phase, stable at ambient conditions. A pressure induced phase transition, observed above 1 GPa, leads to polymorph II, which is also obtained at temperatures below 140 K. Polymorph II can also be maintained at ambient conditions. We have calculated the crystallographic structures and phonon frequencies as a function of temperature, starting from the configurations of the energy minima found by exploring the potential energy surface of crystalline tetracene. The spectra calculated for the first and second deepest minima match satisfactorily those measured for polymorphs I and II, respectively. All published x-ray structures, once assigned to the appropriate polymorph, are also reproduced.Comment: 8 pages, 5 figures, RevTeX4, update after referees report

Selective Functional Movement Assessment (SFMA) Reliability and Proposal of Its Use in Sports

Introduction: The Selective Functional Movement Assessment (SFMA) is a functional movement assessment method to observe movement restrictions in individuals with known musculoskeletal disorders, although it has also been used to evaluate healthy athletes of different sports. Aim: The present paper aimed to evaluate the applicability of SFMA in a clinical setting and to verify whether a student can correctly perform it. Methods: An introductory and explanatory email was sent to the subjects, containing the instructions needed to produce a video with SFMA evaluation movements. SFMA methodology was then used to analyze the received videos. The results between interobserver and intraobserver agreement were compared to the literature, considered the gold standard methods. Results: Twenty-eight subjects (17.71 ± 1.96 years aged) were rated. The functional non-painful scenario (FN) has been assigned more frequently by all raters. The student's intra-rater reliability proved to be moderate (Kappa coefficient 0.49). Results for inter-rater reliability showed that the reliability degree between the senior physiotherapist and student before and after their educational path is good (Kappa coefficient 0.60 and 0.62, respectively). Conclusions: The results of this study showed SFMA intra-rater reliability to be moderate, while inter-rater reliability can be considered good. These characteristics make it a valuable tool for sport's needs, even when used by students

Quasi Harmonic Lattice Dynamics and Molecular Dynamics calculations for the Lennard-Jones solids

We present Molecular Dynamics (MD), Quasi Harmonic Lattice Dynamics (QHLD) and Energy Minimization (EM) calculations for the crystal structure of Ne, Ar, Kr and Xe as a function of pressure and temperature. New Lennard-Jones (LJ) parameters are obtained for Ne, Kr and Xe to reproduce the experimental pressure dependence of the density. We employ a simple method which combines results of QHLD and MD calculations to achieve densities in good agreement with experiment from 0 K to melting. Melting is discussed in connection with intrinsic instability of the solid as given by the QHLD approximation. (See http://www.fci.unibo.it/~valle for related papers)Comment: 7 pages, 5 figures, REVte