132,094 research outputs found
Dihydrofolate reductase: a new molecular target for gold(I) drugs?
No full textDehydrofolate reductasi : a new molecular target for gold(I) drugs?
R. Galassi,a A. Burini,a D. Micozzi,a A. Dolmella,b S. Pucciarellic
a School of Science and Technology, Chemistry Division, University of Camerino, 62032 Camerino (Italy);
b Department of Pharmaceutical Sciences, University of Padova, 35131 Padova (Italy);
c School of Biosciences and Biotechnology, University of Camerino, 62032 Camerino (Italy).
[email protected]
DHFR is an important enzyme mainly involved in the synthesis of pyrimidine and thymine basilar for the DNA replication and hence the cell proliferation. To perform its functions the DHFR enzyme needs the presence of a substrate and a cofactor such as NADPH and H2F.[1] Despite its fundamental importance in the cell’s metabolism this enzyme has never been tested as molecular target for gold(I) compounds which anti-proliferative action was ascertained. In fact, it is generally accepted that gold compounds act as multi-target drug and the proposed mechanisms mainly involve enzymes. Moreover, their action is function of their overall structure and of the nature of the ligands around the central metal atom.
Some pyrazolyl and imidazolyl gold(I) phosphane complexes synthesized by us have shown anticancer properties and they successfully inhibit some seleno-dependent enzymes such as thioredoxina reductase and glutathione peroxidase.[2] To investigate in depth their action on the regards of enzyme, inhibitory studies on DHFR have been carried out. Moreover, appropriate modifications in their structure have been performed in order to get information about the structure/properties relationship.
DTNB assays, stability studies in solution and affinity constant determinations have been performed too. Some conclusions about the possible mechanism of action may be taken accordingly.
Acknowledgements
Authors are grateful to CIRCSMB for Daniela Micozzi fellowship.
References
[1] M. Brandsch, I. Knütter, E. Bosse-Doenecke, J. Pharm. Pharmacol. 2008, 60, 543.
[2] R. Galassi, A. Burini, S. Ricci, M. Pellei, M. P. Rigobello, A. Citta, A. Dolmella, V. Gandin, C Marzano. Dalton Trans., 2012, 41, 530
Thick dielectric films produced by electrophoretic deposition
No full textElectrophoretic deposition (EPD) from colloidal suspensions was utilized for the
preparation of lead zirconate titanate films (PZT) on PZT based substrates. The present
process is developed as a convenient forming process for the development of devices
based on thick ceramic films. The deposition parameters - using EPD - such as colloidal
parameters, deposition voltage and deposition time and the post process parameters, such
as drying velocity and sintering will be controlled. Conductive materials are customarily
used as deposition substrates, but the possibility of depositing on semiconductors (SC)
has recently been demonstrated in this laboratory [1]. This work wants to continue the
research started by Baldisserri et al. that puts emphasis on the analysis of current
transients during constant-voltage deposition as a diagnostic tool for the assessment of
some crucial features of the EPD process [2,3]; the correlations between the above
parameters and final microstructure, by checking the salient features like the film
adhesion, compaction and functionality, will be investigated.
References
[1] C. Baldisserri, D. Gardini, C. Galassi, Sensors & Actuators A 174 (2012) 123.
[2] C. Baldisserri, D. Gardini, C. Galassi, J. Colloid Interface Sci., 347 (2010) 102.
[3] H. Farnoush, J.A. Mohandesi, D. H. Fatmehsari, Ceram. Int., 38 (2012) 6753
Clinical-Analog Research: A Reply to Galassi
No full text The several points raised critically by Galassi are answered. </jats:p
Bulli marionette: bullismi nella cultura del disagio impossibile.
No full textIl disagio possibile, diventa impossibile quando la metafora che lo traduce alla mente lo riveste di molteplici e improbabili mistificazioni, quando sottolinea le gravi insufficienze di una cultura che esclude la malattia e la morte dei suoi alvei vitali. Non è, dunque, la malattia o la morte la causa del disagio impossibile, ma la metafora che le veicola. Così, ad esempio, il bullismo è una metafora che classifica, ordina, condiziona, esclude e condanna. Questo volume, prendendo le mosse da una ricerca svolta nelle scuole del Comune di Bologna, analizza il bullismo nei suoi aspetti dinamici e propone alcuni possibili progetti di intervento
Il bullismo dalla quinta elementare alla terza media
No full textIl saggio presenta una ricerca condotta dagli Autori su 1124 soggetti (597 maschi e 527 femmine) di quinta elementare, 231 soggetti (114 maschi e 117 femmine); prima media, 306 soggetti (172 maschi e 134 femmine); seconda media, 308 soggetti (162 maschi e 146 femmine); terza media, 279 soggetti (149 maschi e 130 femmine) appartenenti agli Istituti comprensivi 3, 4, 5 del Quartiere Navile di Bologna. La presenza del bullismo è stata valutata, a differenza delle altre ricerche in letteratura, utilizzando un questionario con domande riferite a comportamenti specifici indicanti le singole prepotenze piuttosto che ad una nozione generale di "prepotenze", per evitare il rischio che domande dirette più generali sulle prepotenze potessero subire distorsioni, soggette anche a modificazioni con l'età, dovute alla valutazione soggettiva e individuale del concetto di "prepotenza", alla differente autoconsapevolezza della valenza del proprio comportamento, oppure dovute alla differente comprensione di una preliminare definizione operativa di "prepotenza", non immediatamente afferrabile o assimilabile ad una conoscenza quotidiana. Facendo riferimento a comportamenti concreti specifici è ipotizzabile un minore effetto della tendenza dei soggetti ad attribuirsi tratti positivi e socialmente desiderabili (self-serving attribution bias). Sono state prese in considerazione le seguenti dimensioni: la rete amicale e i rapporti con i compagni di classe, le singole prepotenze agite e/o subite, la rappresentazione degli attori, la gravità morale attribuita, le reazioni alle prepotenze, i luoghi delle prepotenze. Dall’analisi dei dati, sottoposti a statistiche descrittive ed inferenziali, sono emersi i seguenti risultati significativi: il fenomeno del bullismo risulta essere di dimensioni rilevanti e coinvolge direttamente come bulli o come vittime circa la metà dei soggetti; le vittime presentano minori relazioni amicali degli altri e tendono ad essere isolate; la rete amicale rappresenta una barriera protettiva nei confronti del rischio di diventare vittima, anche in quanto concorre all'autostima, mentre, contrariamente all'immagine stereotipata dell'alunno prepotente che reagisce aggressivamente all'isolamento sociale, i bulli noti presentano relazioni amicali quantitativamente differenti dagli altri; le prepotenze più frequenti sono quelle più "tollerate" dai contesti educativi; le prepotenze vengono agite in prevalenza verso ragazzi appartenenti al proprio sesso; la reazione prevalente alle prepotenze da parte di coloro che non sono né bulli né vittime è quella dell'evitamento della gestione diretta della prepotenza; le prepotenze avvengono prevalentemente nell'aula di lezione, sotto gli occhi degli insegnanti, e non fuori dalla scuola o in luoghi appartati, considerati tradizionalmente i luoghi a rischio; nei bulli c'è una tendenza a sottostimare la gravità delle prepotenze compiute e una carente auto ed eteroregolazione che insieme ai meccanismi di dissonanza cognitiva e di disimpegno morale contribuiscono alla autoassoluzione che accompagna il bullismo. I risultati della ricerca sono discussi sulla base delle principali teorie di riferimento della pedagogia della cognizione
Thick composite magnetoelectric films by electrophoretic deposition
No full textElectrophoretic deposition (EPD) from colloidal suspensions was utilized for the preparation of composite magneto-dielectric films on a conductive substrate. The present process is developed as a convenient forming process for the development of devices based on thick magneto-dielectric films [1]. The deposition parameters - using EPD - such as colloidal parameters, deposition voltage and deposition time and the post process parameters, such as drying velocity and sintering will be controlled. This work aims to control the fillers/matrix ratio during the deposition and obtain a good adhesion, compaction and functionality of the composite film after the heat treatment. Measurements results for the current transients during constant-voltage deposition and the correlated deposited mass are presented [2, 3].1] A.O. Karilainen, P.M.T. Ikonen, C.R. Simovski, S.A. Tretyakov, A.N. Lagarkov, S.A. Maklakov, K.N. Rozanov, and S.N. Starostenko, Experimental studies on antenna miniaturisation using magneto-dielectric and dielectric materials, IET Microw. Antennas Propag., vol. 5, no. 4, pp. 495-502, 2011. 2] C. Baldisserri, D. Gardini and C. Galassi, An analysis of current transients during electrophoretic deposition (EPD) from colloidal TiO2 suspensions, Journal of Colloid and Interface Science 347 (2010) 102-111 3] H. Farnoush, J.A. Mohandesi, D. H. Fatmehsari and F. Moztarzadeh, A kinetic study on the electrophoretic deposition of hydroxyapatite-titania nanocomposite based on a statistical approach, Ceramics International 38 (2012), 6753-676
Preliminary Studies on the Synthesis and Antimicrobial activity of TiO2/Ag/Au nanoparticles on materials for sanitation of indoor Ambient Assisted Living environments.
No full textPreliminary Studies on the Synthesis and Antimicrobial activity of TiO2/Ag/Au nanoparticles on materials for sanitation of indoor Ambient Assisted Living environments.
Ramadori A. T. a,b Galassi R.,a Micozzi, D.,c Pucciarelli, S. c
a School of Science and Technology, Chemistry Division, University of Camerino, Via S. Agostino 1, 62032 Camerino; e-mail: [email protected]
b Fellow from T.R.A.S.P.A.R.E.N:T.E project
c School of Biology, Chemistry Division, University of Camerino, Via S. Agostino 1, 62032 Camerino;
Infectious diseases contracted in the home environment are still a significant problem in the western world due to the excessive use of antibiotics, the occurrence of bacterial resistance and not always correct behavior of the population; prevention and personal hygiene are able to dramatically reduce the risk of transmission, but in some circumstances, for example in the case of older people not fully self-sufficient, long-term care in hospitals and residential health and social environments, which are overcrowded and poorly ventilated, normal personal and domestic hygiene measures may be insufficient.1 Hence, in the development of new technology for the improvement of the sanitation of environments and objects, the use of nanoparticle (NP) systems2 based on Au, Ag and TiO2 NPs was taken into consideration as additives in plasters, resins for water-based paints and varnishes. TiO2 has been purchased, while different Au and Ag NPs syntheses have been perfomed.3 The NPs have been characterized by spectroscopic methods such as UV-vis or IR spectroscopy. Different formulations and concentrations of NPs have been attempted. The obtained samples were tested to evaluate their antimicrobial activity on pathogenic coltures.
References:
1) a) Bruce, N.; Perez-Padilla, R.; Albalak, R. Bull.World Health Org. 2000, 78, 1078-1092. b) Gandara, A.; Mota, L. C.; Gibbs S. G. Environ. Health Perspective 2006, 114, 1859-1864.
2) Ashavani, K.; Praveen, K. V.; Pulickel, M. A.; George, J. Nature Materials 2008, doi:10.1038/nmat2099.
3) a) Wojtysiak, S.; Kudelski, A. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2012, 410, 45-51. b) Rohiman, A., Anshori, I., Surawijaya, A., Idris, I. AIP Conf. Proc. 2011, 1415, 39-42. c) Cubillana-Aguilera, L.M.; Franco-Romano, M.; Gil, M.L.A.; Naranjo-Rodríguez, I.; Hidalgo-Hidalgo de Cisneros, J. L.; Palacios-Santander, J.M. Ultrasonics Sonochemistry, 2011, 18, 789-794
PZT film on silicon by electrophoretic deposition
No full textIn recent times direct integration of ferroelectrics on silicon wafer has been attracting interest [1]. Electrophoretic deposition (EPD) was investigated in this laboratory [2] as an alternative mean to produce lead zirconate titanate (PZT) film on silicon wafers followed by sintering at 850-950°C. EPD is an easily implemented deposition technique that requires only basic laboratory gear and a sufficiently stable colloidal suspension to produce ceramic and electroceramic films with thickness in the 100 nm - 10 mm range3 . It has been found that the EPD of niobium-doped lead zirconate titanate (PZTN), performed in ethanol-based suspensions of PZT on bare silicon wafers on which Al/Si alloyed ohmic contacts were made, produced smooth green films that strongly pinned to the silicon substrate after sintering. Thick and well-adhered sintered PZT films on silicon having thickness about 50 µm were thus obtained. Such structures could be the core of novel on-chip sensors/actuators. The results of the production of thick PZT films by EPD and sintering and some characterizations of the same are reported. [1] M. Y. Gureev, A. K. Tangatsev, N. Setter; IEEE T Ultrason Ferr, 58, 1959 (2011) [2] C. Baldisserri, D. Gardini, C. Galassi; Sensor Actuat A-Phys, 174, 123 (2012) [3] P. Sarkar, P.S. Nicholson; J Am Ceram Soc, 79, 1987 (1996
Pathogenesis and treatment of secondary hyperparathyroidism in dialysis patients : the role of paricalcitol
No full textHemodialysis (HD) patients are commonly affected by secondary hyperparathyroidism
(SHPT), in which 3 well-known factors are usually involved: hypocalcemia,
hyperphosphatemia and calcitriol deficiency. Classically, high parathyroid
hormone (PTH) levels cause bone-associated diseases, such as osteitis fibrosa and
renal osteodystrophy, but more recently it has been demonstrated the link between
SHPT and a systemic toxicity, with a major role in determining cardio-vascular
disease, including arterial calcification, endocrine disturbances, compromised
immune system, neurobehavioral changes, and altered erythropoiesis. Treatment
with calcitriol (CT), the active form of vitamin D, reduces parathyroid hormone
(PTH) levels, but may result in elevations in serum calcium (Ca) and phosphorus
(P), increasing the risk of cardio-vascular calcification in the HD population.
Several new vitamin D analogs have been developed and investigated with the
rationale to treat SHPT with a reduced risk of hypercalcemia and
hyperphosphatemia in HD patients. Paricalcitol (1,25-dihydroxy-19-nor-vitamin
D(2), 19-Nor-D(2)) is a vitamin D analog that suppresses PTH secretion with
minimal increases on serum calcium and phosphate levels. It was demonstrated that
paricalcitol prevents vascular calcification in experimental models of renal
failure, compared with calcitriol. Furthermore, 19-Nor-D(2) is the first analog
approved for use in HD patients and is available for i.v. and oral
administration, commonly 3 times weekly after HD. The purpose of the present
review is to analyze the pathogenesis and treatment of SHPT in HD patients, and
the role of paricalcitol in the prevention of arterial calcification
Solventless VOC chemisorption by silver metallocycles
No full textSolventless VOC chemisorption by silver metallocycles
Oumarou C. S.a, Tekarli S.,b Nesterov V.,b Omary M. A.,b Burini A.,a Galassi R.,a
aSchool of Science and Technology, Chemistry Division, University of Camerino, Via S. Agostino 1, 62032 Camerino; e-mail: [email protected]
b Department of Chemistry, University of North Texas, Denton, TX 76203, USA
Prior work has focused on detection/sensing aspects of VOCs,[1] this work proposes a method for their simultaneous filtration and removal through their strong chemisorption to a silver(I) metallocyclic trimer.[2] A solid cyclotrimer can quantitatively remove entire molar integers of VOCs (1-3 equivalents of VOCs per mole of the nitrated trimer) from the vapor phase in a solventless “green” chemical process, which is unprecedented for this class of cyclic d10 complexes.
Figure 1. Illustration of quadrupole-dipole interactions involving the [Ag(μ-Pz-2CF3)]3 or [Ag(3,5-(NO2)2pz)]3 trimers and acetonitrile using M06/CEP-31G(d). MEP surfaces are plotted in two manners, either mapped on electron density surfaces (rainbow plots with the color scale shown; isodensity = 0.0004) or positive (blue) and negative (red) regions in space (range = ± 2.2 a. u.; isodensity = 0.02)
[1] Yaghi et al., PNAS 2008, 105, 11623
[2] R. Galassi, S. Ricci, A. Burini, A. Macchioni, L. Rocchigiani, F. Marmottini, S. Tekarli, V. Nesterov, M. A. Omary, J. Am. Chem. Soc., 2013, submitted
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