170,027 research outputs found
Ion/neutral complexes generated during unimolecular fragmentation: Intra-complex hydride abstraction by tert-butyl cations from electron-rich and electron-poor 1,3-diphenylpropanes
No full textMatthias C, Cartoni A, Kuck D. Ion/neutral complexes generated during unimolecular fragmentation: Intra-complex hydride abstraction by tert-butyl cations from electron-rich and electron-poor 1,3-diphenylpropanes. INTERNATIONAL JOURNAL OF MASS SPECTROMETRY. 2006;255-256:195-212.The hydride transfer and proton transfer occurring between the constituents of ion/neutral complexes of tert-butyl cations and electron-rich and electron-poor 1,3-diphenylpropanes, [(CH3)(3)C+ C6H5CH2CH2CH2C6H4X] were investigated by use of CI/MIKE spectrometry of nine 1-(tert-butylphenyl)-3-arylpropanes and 16 site-specific deuterium-labeled isotopomers. The competition between H- abstraction by the (CH3)(3)C+ ion from the neutral arene and H+ transfer to it was found to be strongly affected by the electron-donating substituents, in particular by X = OCH3, on the one hand, and X = F and CF3, on the other, suggesting that the 1,3-diphenylpropane molecule within the I/N complex acts and reacts as a bidentate solvating partner to the carbocation. The effect of the substituents X on the regioselectivity of the intra-complex hydride abstraction from the two benzylic CH2 groups, k(gamma-H)/k(alpha-H), and their influence on the kinetic isotope effect (k(H)/k(D))(gamma), operating during the abstraction from the substituted benzylic moiety, were determined in a semi-quantitative approach by assuming (k(H)/k(D))(alpha) = 1.60, the generally observed value for the unsubstituted benzylic moiety. The regioselectivity range was found to span almost three orders of magnitude, from k(gamma-H)/k(alpha-H) >= 11.2 for the complex [(CH3)(3)C+ (C6H5CH2CH2CH2C6H4)-H-alpha-H-gamma(p-OCH3)] to k(gamma-H)/k(alpha-H) <= 0.04 for the complex [(CH3)(3)C+ (C6H5CH2CH2CH2C6H4)-H-alpha-H-gamma(p-CF3)]. (C) 2006 Elsevier B.V. All rights reserved
CZE determination of somatostatin in pharmaceutical preparations
No full textWe propose a simple and accurate method for CE quantitative determination of somatostatin in pharmaceutical preparations. The method is specific for somatostatin as indicated by the resolution between the analyte and the analogue peptides which differ from somatostatin by one aminoacid. The linearity range is from 0.02 to 0.35 mg/ml. The recovery of the somatostatin from a pharmaceutical product is about 100.0%. (C) 2000 Elsevier Science B.V. All rights reserved
Centro Residenziale per le Cure Palliative - Hospice presso Ospedale "A. e C. Cartoni" di Rocca Priora (Roma)
No full textIl progetto preliminare, definitivo ed esecutivo dell'Hospice a Rocca Priora ha previsto la riconversione funzionale e ristrutturazione parziale dell'Ospedale "A. e C. Cartoni" nell'ambito degli interventi previsti dalla Legge n. 39/99 "Programma per la realizzazione di strutture per le cure pallaitive nella Regione Lazio". Il progetto della prof. arch. Tiziana Ferrante è stato curato per gli aspetti impiantistici dal prof. ing. Livio De Santoli e dall'ing. Alberto Dellepiane per le verifiche strutturali
[Fungal lesions of the organs of the upper abdomen].
No full textThe authors report on 14 cases of fungal parenchymal infections of the abdomen detected with CT and/or US in immunodepressed patients. Image patterns and the capabilities of the two diagnostic techniques are analyzed in the early detection of fungal lesions. CT was the first-choice examination, followed by US, in 9 patients; laboratory tests followed in 3 cases; US was performed first (and CT second) in 1 patient; finally, US alone was performed in 1 patient. The information yielded by CT and that given by US overlapped in 8/9 cases: in the extant patient, US demonstrated multiple fungal microabscesses of liver, while CT was negative, probably due to low liver density. CT patterns were multiple, small and round nonenhanced areas. Since the indiscriminate administration of intravenous contrast medium is unsuitable, CT cannot be performed first. On the other hand, in several patients liver CT with no contrast medium gave the same results for venous and fungal lesions. Compared with CT, US is a safer technique which is easier to perform and to evaluate. Therefore, US should be the exam of choice in immunodepressed patients with suspected fungal lesions. US is likely to demonstrate, in most cases, a pathologic condition (fungal microabscesses) as well as vascular and biliary anatomy
An experimental and theoretical investigation of XPS and NEXAFS of 5-halouracils
No full textThe C, N and O 1s excitation and ionization processes of 5X-uracil (X = F, Cl, Br, and I) were investigated using near edge X-ray absorption fine structure (NEXAFS) and X-ray photoemission (XPS) spectroscopies. This study aims at the fine assessment of the effects of the functionalization of uracil molecules by halogen atoms having different electronegativity and bound to the same molecular site. Two DFT-based approaches, which rely on different paradigms, have been used to simulate the experimental spectra and to assign the corresponding features. The analysis of the screening of the core holes of the different atoms via electronic charge density plots has turned out to be a useful tool to illustrate the competition between the partially aromatic and partially conjugate properties of this class of molecules. © 2018 the Owner Societies
Methylmethacrylate-based polymeric nanoparticles as platform for multimodal imaging
No full textCancer therapy using nanomaterials has progressed significantly over the years. Radiation therapy, chemotherapy, or combination of these is used to deal with the serious threats of malignancy. However, surgical resection is the most effective therapy since it reduces the probability of tumor recurrence. While some tumors can be resected easily, others may be in hard-to-reach locations. Radioguided surgery (RGS) is a technique that may enable the surgeon to evaluate in real time the completeness of the tumor lesion resection [1]. With high development in nanoscience, nanostructured polymers have attracted high interest especially in cancer diagnosis and therapy due to their unique properties, such as porous structure, and high surface than their bulk counterparts [2,3]. This work concerns the preparation and characterization of methylmethacrylate-based copolymeric nanoparticles via surfactant-free emulsion polymerization using radical initiator at 80°C. Acrylic acid and N,N-dimethylacrylamide were used as comonomer to obtain P(MMA-co-AA) and P(MMA-co-DMAA) polymeric NPs. The effects of monomers ratio and initiator were studied to optimize average particle hydrodynamic diameter and polydispersity index of the final particles. Then, the obtained polymeric nanoparticles were loaded with 89Y, as a model of β- radioisotope 90Y, by addition of an aqueous solution of YCl3. NPs as imaging probe were obtained by physical encapsulation of xanthene dye fluorescein isothiocyanate isomer I (FITC) into the inner core of the copolymeric NPs. The obtained NPs were used for in vitro biocompatibility evaluation in human glioblastoma cell line. The copolymers were characterized by FTIR, and the composition was determined by 1H-NMR and XPS spectroscopies. The morphology and particle size distribution were determined through dynamic light scattering (DLS), atomic force microscopy (AFM) and electron microscopies (SEM/TEM). As a proof of concept, bright fluorescence of FITC encapsulated NPs was studied via fluorescence microscopy.
[1] F. Collamati, D. Maccora, S. Alfieri, V. Bocci, A. Cartoni, A. Collarino, M. De Simoni, M. Fischetti, I. Fratoddi, A. Giordano, C. Mancini-Terracciano, R. Mirabelli, S. Morganti, G. Quero, D. Rotili, T. Scotognella, E. Solfaroli Camillocci, G. Traini, I. Venditti, R. Faccini, Sci. Rep. 2020, 10, 4015.
[2] I. Venditti, A. Cartoni, L. Fontana, G. Testa, F.A. Scaramuzzo, R. Faccini, C. Mancini-Terracciano, E. Solfaroli Camillocci, S. Morganti, A. Giordano, T. Scotognella, D. Rotili, V. Dini, F. Marini, I. Fratoddi, Colloids Surf. A 2017, 532, 125-131.
[3] P. Guang-Yu, J. Hao-Ran, Z. Ya-Xuan, S. Wei, C. Xiao-Tong, W. Fu-Gen, ACS Appl. Nano Mater. 2018, 1, 2885-2897
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Breast muscle and plasma metabolomics profile of broiler chickens exposed to chronic heat stress conditions
No full textUnderstanding the variations of muscle and plasma metabolites in response to high environmental temperature can provide important information on the molecular mechanisms related to body energy homeostasis in heat-stressed broiler chickens. In this study, we investigated the effect of chronic heat stress conditions on the breast muscle (Pectoralis major) and plasma metabolomics profile of broiler chickens by means of an innovative, high-throughput analytical approach such as the proton nuclear magnetic resonance (1H NMR) spectrometry. A total of 300 Ross 308 male chicks were split into two experimental groups and raised in either thermoneutral conditions for the entire rearing cycle (0–41 days) (TNT group; six replicates of 25 birds/each) or exposed to chronic heat stress conditions (30 °C for 24 h/day) from 35 to 41 days (CHS group; six replicates of 25 birds/each). At processing (41 days), plasma and breast muscle samples were obtained from 12 birds/experimental group and then subjected to 1H NMR analysis. The reduction of BW and feed intake as well as the increase in rectal temperature and heterophil: lymphocyte ratio confirmed that our experimental model was able to stimulate a thermal stress response without significantly affecting mortality. The 1H NMR analysis revealed that a total of 26 and 19 molecules, mostly related to energy and protein metabolism as well as antioxidant response, showed significantly different concentrations respectively in the breast muscle and plasma in response to the thermal challenge. In conclusion, the results obtained in this study indicated that chronic heat stress significantly modulates the breast muscle and plasma metabolome in fast-growing broiler chickens, allowing to delineate potential metabolic changes that can have important implications in terms of body energy homeostasis, growth performance and product quality
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