High-resolution kinetic energy release distributions and dissociation energies for fullerene ions C(n)(+), 42 \u3c= n \u3c= 90

We have measured the kinetic energy released in the unimolecular dissociation of fullerene ions, C(n)(+)--\u3eC(n-2)(+)+C(2), for sizes 42less than or equal tonless than or equal to90. A three-sector-field mass spectrometer equipped with two electric sectors has been used in order to ensure that contributions from isotopomers of different masses do not distort the experimental kinetic energy release distributions. We apply the concept of microcanonical temperature to derive from these data the dissociation energies of fullerene cations. They are converted to dissociation energies of neutral fullerenes with help of published adiabatic ionization energies. The results are compared with literature values. (C) 2004 American Institute of Physics

Near-infrared photoabsorption by C(60) dianions in a storage ring

We present a detailed study of the electronic structure and the stability of C(60) dianions in the gas phase. Monoanions were extracted from a plasma source and converted to dianions by electron transfer in a Na vapor cell. The dianions were then stored in an electrostatic ring, and their near-infrared absorption spectrum was measured by observation of laser induced electron detachment. From the time dependence of the detachment after photon absorption, we conclude that the reaction has contributions from both direct electron tunneling to the continuum and vibrationally assisted tunneling after internal conversion. This implies that the height of the Coulomb barrier confining the attached electrons is at least similar to 1.5 eV. For C(60)(2-) ions in solution electron spin resonance measurements have indicated a singlet ground state, and from the similarity of the absorption spectra we conclude that also the ground state of isolated C(60)(2-) ions is singlet. The observed spectrum corresponds to an electronic transition from a t(1u) lowest unoccupied molecular orbital (LUMO) of C(60) to the t(1g) LUMO+1 level. The electronic levels of the dianion are split due to Jahn-Teller coupling to quadrupole deformations of the molecule, and a main absorption band at 10723 cm(-1) corresponds to a transition between the Jahn-Teller ground states. Also transitions from pseudorotational states with 200 cm(-1) and (probably) 420 cm(-1) excitation are observed. We argue that a very broad absorption band from about 11 500 cm(-1) to 13 500 cm(-1) consists of transitions to so-called cone states, which are Jahn-Teller states on a higher potential-energy surface, stabilized by a pseudorotational angular momentum barrier. A previously observed, high-lying absorption band for C(60)(-) may also be a transition to a cone state

Lifetimes of C-60(2-) and C-70(2-) dianions in a storage ring

C-60(2-) and C-70(2-) dianions have been produced by electrospray of the monoanions and subsequent electron pickup in a Na vapor cell. The dianions were stored in an electrostatic ring and their decay by electron emission was measured up to 1 s after injection. While C-70(2-) ions are stable on this time scale, except for a small fraction of the ions which have been excited by gas collisions, most of the C-60(2-) ions decay on a millisecond time scale, with a lifetime depending strongly on their internal temperature. The results can be modeled as decay by electron tunneling through a Coulomb barrier, mainly from thermally populated triplet states about 120 meV above a singlet ground state. At times longer than about 100 ms, the absorption of blackbody radiation plays an important role for the decay of initially cold ions. The tunneling rates obtained from the modeling, combined with WKB estimates of the barrier penetration, give a ground-state energy 200 +/- 30 meV above the energy of the monoanion plus a free electron and a ground-state lifetime of the order of 20 s. (c) 2006 American Institute of Physics

Bronchopulmonary Dysplasia: Comparison Between the Two Most Used Diagnostic Criteria

Objectives: To compare the Shennan\u27s and the consensus definition of Bronchopulmonary Dysplasia (BPD) from the National Institutes of Health (NIH) workshop and analyze specific risk factors associated with each definition. Study design: Retrospective analysis of records of 274 infants admitted to a level IV intensive care unit. Infants were classified as having BPD or no BPD by both definitions. Differences in incidence and risk factors were analyzed. Statistical methods included descriptive statistics, comparative tests, and marginal logistic regression modeling. Results: The estimated difference in prevalence was 32% [95% CI: (26%, 37%), (p \u3c 0.0001)] between both criteria. The prevalence of BPD was 80% higher based on the NIH criteria [RR = 1.80; 95% CI: (1.58, 2.06)]. Infants with no BPD by the Shennan definition were breathing room air with or without positive or continuous pressure support and were most likely to be discharged home on oxygen [OR = 4.47, 95% CI: (1.20, 16.61), p = 0.03]. Gestational age, birth weight, and 1-min Apgar score predicted BPD by both definitions. Chorioamnionitis increased the risk of BPD by the Shennan definition but was associated with lower risk by the NIH criteria. IUGR was associated with BPD by the Shennan definition and with severe BPD by the NIH criteria. Conclusion: Compared to the Shennan\u27s definition, the NIH consensus identified 80% more infants with BPD and is a better predictor of oxygen requirement at discharge. Until a new better criteria is develop, the NIH consensus definition should be used across centers

Simplification of the Finnegan Neonatal Abstinence Scoring System: Retrospective Study of Two Institutions in the USA

Objective To develop a simplified Finnegan Neonatal Abstinence Scoring System (sFNAS) that will highly correlate with scores ≥ 8 and ≥12 in infants being assessed with the FNAS. Design, setting and participants This is a retrospective analysis involving 367 patients admitted to two level IV neonatal intensive care units with a total of 40 294 observations. Inclusion criteria included neonates with gestational age ≥ 37 0/7 weeks, who are being assessed for neonatal abstinence syndrome (NAS) using the FNAS. Infants with a gestational age \u3c 37 weeks were excluded. Methods A linear regression model based on the original FNAS data from one institution was developed to determine optimal values for each item in the sFNAS. A backward elimination approach was used, removing the items that contributed least to the Pearson’s correlation. The sFNAS was then cross-validated with data from a second institution. Results Pearson’s correlation between the proposed sFNAS and the FNAS was 0.914. The optimal treatment cut-off values for the sFNAS were 6 and 10 to predict FNAS scores ≥ 8 and ≥ 12, respectively. The sensitivity and specificity of these cut-off values to detect FNAS scores ≥ 8 and ≥ 12 were 0.888 and 0.883 for a cut-off of 6, and 0.637 and 0.992 for a cut-off of 10, respectively. The sFNAS cross-validation resulted in a Pearson’s correlation of 0.908, sensitivity and specificity of 0.860 and 0.873 for a cut-off of 6, and 0.525 and 0.986 for a cut-off of 10, respectively. Conclusion The sFNAS has a high statistical correlation with the FNAS, and it is cross-validated for the assessment of infants with NAS. It has excellent specificity and negative predictive value for identifying infants with FNAS scores ≥ 8 and ≥ 12

Numerical simulation of the thermal fragmentation process in fullerene C60

The processes of defect formation and annealing in fullerene C60 at T=(4000-6000)K are studied by the molecular dynamics technique with a tight-binding potential. The cluster lifetime until fragmentation due to the loss of a C2 dimer has been calculated as a function of temperature. The activation energy and the frequency factor in the Arrhenius equation for the fragmentation rate have been found to be Ea = (9.2 +- 0.4) eV and A = (8 +- 1)10^{19} 1/s. It is shown that fragmentation can occur after the C60 cluster loses its spherical shape. This fact must be taken into account in theoretical calculations of Ea.Comment: 12 pages, 3 figure

Bronchopulmonary Dysplasia: Comparison Between the Two Most Used Diagnostic Criteria

Objectives: To compare the Shennan's and the consensus definition of Bronchopulmonary Dysplasia (BPD) from the National Institutes of Health (NIH) workshop and analyze specific risk factors associated with each definition.Study design: Retrospective analysis of records of 274 infants admitted to a level IV intensive care unit. Infants were classified as having BPD or no BPD by both definitions. Differences in incidence and risk factors were analyzed. Statistical methods included descriptive statistics, comparative tests, and marginal logistic regression modeling.Results: The estimated difference in prevalence was 32% [95% CI: (26%, 37%), (p < 0.0001)] between both criteria. The prevalence of BPD was 80% higher based on the NIH criteria [RR = 1.80; 95% CI: (1.58, 2.06)]. Infants with no BPD by the Shennan definition were breathing room air with or without positive or continuous pressure support and were most likely to be discharged home on oxygen [OR = 4.47, 95% CI: (1.20, 16.61), p = 0.03]. Gestational age, birth weight, and 1-min Apgar score predicted BPD by both definitions. Chorioamnionitis increased the risk of BPD by the Shennan definition but was associated with lower risk by the NIH criteria. IUGR was associated with BPD by the Shennan definition and with severe BPD by the NIH criteria.Conclusion: Compared to the Shennan's definition, the NIH consensus identified 80% more infants with BPD and is a better predictor of oxygen requirement at discharge. Until a new better criteria is develop, the NIH consensus definition should be used across centers

Il consolidamento degli apparati decorativi mediante dispositivi a memoria di forma: il progetto di ricerca sui dipinti murali di via dell’Abbondanza a Pompei

Il progetto di ricerca, iniziato durante il cantiere di restauro, recentemente concluso, ha riguardato gli interventi di consolidamento, conservazione e restauro su alcune facciate delle antiche botteghe di via dell'Abbondanza (Regio IX, Insulae 7 e 11) nel sito archeolo-gico di Pompei. Questi fronti sono caratterizzati da alcuni dei dipinti murali più importanti e le iscrizioni elettorali. Il progetto denominato “Da Asellina a Verecundus: ricerca, restauro e monitoraggio sulle pitture di alcune celebri botteghe di via dell'Abbondanza a Pompei (Regio IX, Insulae 7 e 11)” nato dalla collaborazione fra la Soprintendenza Ar-cheologica di Pompei, la Facoltà di Architettura Valle Giulia dell’Università di Roma La Sapienza, la Facoltà di Architettura e il Centro DIAPReM dell’Università di Ferrara e la II Facoltà di Ingegneria (sede di Forlì) dell’Università di Bologna, con l’obiettivo della salva-guardia di alcune strutture architettoniche e degli apparati pittorici e decorativi fra i più importanti di tutta la città. L’intervento di restauro, in particolare, ha riguardato alcune botteghe poste sul braccio del decumano massimo compreso fra il Foro e Porta Sarno. Tali facciate, riportate alla luce durante gli scavi condotti nel 1912 da Vittorio Spinazzola, appartengono all’officina coactiliaria (Regio IX, VII, 7-5); ad una casa privata (Regio IX, VII, 3); all’officina infectoria (Regio IX, VII, 2); all’officina coactiliaria (Regio IX, VII,1); al compitum (Regio IX, XI, 1); al thermopolium di Asellina, rivendita di bevande calde (Regio IX, XI, 2). Una sezione del progetto di ricerca ha riguardato la sperimentazione di nuovi dispositivi tecnologici finalizzati al restauro di pitture murali e basati su leghe a memoria di forma (SMA) per risolvere i problemi di consolidamento altrimenti risolto per mezzo di non-reversibile o invadente metodologie. Una delle applicazioni innovative di questi dispositivi riguarda il movimento delle lastre in policarbonato in grado di proteggere le pit-ture murali. Il particolare contesto del progetto di ricerca è collocato sul confine tra l'area scavata e l'area ancora sepolta, così, è stato particolarmente interessante mettere a fuoco le ricerche sul consolidamento delle decorazioni e pitture murali, anche attraverso lo studio delle interventi di Vittorio Spinazzola durante i lavori di scavo, all'inizio del XX secolo

Nutrient intake during pregnancy and adherence to dietary recommendations: The mediterranean phime cohort

Few studies provide a detailed description of dietary habits during pregnancy, despite the central role of nutrition for the health of the mother and offspring. This paper describes the dietary habits, energy and nutrient intake in pregnant women from four countries belonging to the Mediterranean PHIME cohort (Croatia, Greece, Italy and Slovenia) and evaluates their adherence to the European Food Safety Authority (EFSA) recommendations. A total of 1436 women were included in the present analysis. Maternal diet was assessed using a food frequency questionnaire (FFQ). The mean macro and micronutrient intakes were estimated and compared with the dietary reference values (DRVs). The percentage distribution of the 16 food groups in the total intake of each macronutrient was estimated. All women shared a similar diet during pregnancy; almost all the women in the four countries exceeded the DRV for sugars, and the total fat intake was above the DRV in most women in all the countries, as was the contribution of saturated fatty acids (SFAs) to the total energy intake. In all four countries, we observed an increased risk of micronutrient deficiency for iron, folate and vitamin D. Shared guidelines, implemented at both the national and European level, are essential to improve the maternal nutritional status during pregnancy

Estrogen-Eluting Stents

Coronary stenting is routinely utilized to treat symptomatic obstructive coronary artery disease. However, the efficacy of bare metal coronary stents has been historically limited by restenosis, which is primarily due to excessive neointima formation. Drug-eluting stents (DES) are composed of a stainless steel backbone encompassed by a polymer in which a variety of drugs that inhibit smooth muscle cell proliferation and excessive neointima formation are incorporated. DES have significantly reduced the incidence of restenosis but are also associated with a small (~0.5% per year) but significant risk of late stent thrombosis. In that regard, estrogen-eluting stents have also undergone clinical evaluation in reducing restenosis with the additional potential benefit of enhancing reendothelialization of the stent surface to reduce stent thrombosis. Estrogen directly promotes vasodilatation, enhances endothelial healing, and prevents smooth muscle cell migration and proliferation. Due to these mechanisms, estrogen has been postulated to reduce neointimal hyperplasia without delaying endothelial healing. In animal studies, estrogen treatment was effective in decreasing neointimal hyperplasia after both balloon angioplasty and stenting regardless of the method of drug delivery. The first uncontrolled human study using estrogen-coated stents demonstrated acceptable efficacy in reducing late lumen loss. However, subsequent randomized clinical trials did not show superiority of estrogen-eluting stents over bare metal stents or DES. Further studies are required to determine optimal dose and method of estrogen delivery with coronary stenting and whether this approach will be a viable alternative to the current DES armamentarium