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The aim of this work was to evaluate the correlation between different methods (organoleptic evaluation, gas chromatography, salivary ?-galactosidases activity) for the evaluation of halitosis in children. The secondary purpose was to investigate the influence of orthodontic treatment on halitosis.Study Design: Oral malodour was detected with different methods in 50 children in the Paediatric Dentistry Unit, University of Rome Tor Vergata, Rome, Italy. During the dental visit, level of oral hygiene, tongue coating scores and presence of an orthodontic device, fixed or mobile, were recorded. Two trained and calibrated operators performed the organoleptic evaluation; the Oral ChromaTM device was used for the volatile sulfur compounds (VSCs) quantification and salivary ?-galactosidases (S?-g) activity was evaluated through the spectrophotometric method.The Cohen's Kappa score was used to evaluate the level of agreement between the operators. The Pearson's correlation coefficient was used to evaluate the linear relationship between continuous variables (e.g. S?-g vs. VSCs values) and the Spearman's correlation coefficient was calculated for ordinal variables (e.g. organoleptic scores) vs. other parameters. The LSD test was used to compare the parameters analysed in the study.A positive and significant correlation between the organoleptic evaluation, the S?-g, the levels of hydrogen sulfide (H2S) and methyl mercaptan (CH3SH) was found. The Spearman's correlation has shown that organoleptic scores were significantly correlated with S?-g (0.664, p0.001) and the Oral ChromaTM measurements of H2S (0.538, p0.001) and Ch3SH (0.316, p=0.026). The Pearson's correlation showed that S?-g was statistically significantly correlated with the Oral ChromaTM measurements of H2S (0.379 p=0.007) and Ch3SH (0.299, p=0.0035). Stratifying results for orthodontic treatment, it was possible to show that children under orthodontic treatment, both fixed or removable, were characterised by higher level of S?-g. The organoleptic evaluation and Oral ChromaTM measurements showed that children wearing fixed orthodontic were characterised by higher scores.There was a significant correlation between the three different techniques for the evaluation of oral malodour in children. Like in the adult population, the increase of S?-g activity was associated with oral malodour. The presence of fixed orthodontic appliances was correlated to increased scores of all methods for the evaluation of halitosis.

Photobiomodulation (PBM) can induce a set of different biological modulators either in vitro or in vivo. Experimental evidence has highlighted the role of light effects on the mechanisms related to inflammation, apoptosis and autophagy. The goal of this project was the evaluation of PBM on U937, an established cell line of histiocytic lymphoma origin. Several aspects of modulation of proinflammatory pathways were analyzed and autophagic and proapoptotic mechanisms related to low laser light exposure of cells were studied. As a source of low energy light emission, we used an NIR-LED device, characterized by an 880 nm-wavelength as light source. Flow cytometry analysis was performed on supernatants of controls and treated U937 cells to detect inflammatory cytokine levels. In order to evaluate NF-kB and caspase3 expressions, Western blot analysis was performed according to standard procedures. In this report, we show the effect of PBM on a monocyte/macrophage established tumor cell line (U-937). We demonstrate that LED exposure, in the presence or absence of lipopolysaccharide (LPS), activates cell degranulation, increased expression of Interleukin-8 (IL-8) and modulation of beta galactosidase activity. Evidence shows that the well-known pro-inflammatory nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) and the apoptotic marker (caspase3/cleaved-caspase3 ratio) are up-regulated in response to a proinflammatory biochemical pathway.

The aim of this work is to verify a correlation between the grade of inflammation and the concentration of PGE2 in human dental pulp. A total of 25 human dental pulps were examined by histological analysis and radioimmunologic dosage of PGE2. The pulps used in this experiment were from healthy and symptomatic teeth; the first ones were collected from teeth destined to be extracted for orthodontic reasons. An increase was observed of PGE2 in reversible pulpitis compared with healthy pulps and with the irreversible pulpitis and the clear decrease of these when NSAIDs are taken. This study demonstrates that PGE2 level is correlated to histological analysis thus allowing to distinguish symptomatic teeth in reversible and irreversible pulpitis.

Service continuity is one of the major aspects in the definition of the quality of the electrical energy, for this reason the research in the field of faults diagnostic for distribution systems is spreading ever more. Moreover the increasing interest around modern distribution systems automation for management purposes gives faults diagnostics more tools to detect outages precisely and in short times. In this paper, the applicability of an efficient fault location and characterization methodology within a centralized monitoring system is discussed. The methodology, appropriate for any kind of fault, is based on the use of the analytical model of the network lines and uses the fundamental components rms values taken from the transient measures of line currents and voltages at the MV/LV substations. The fault location and identification algorithm, proposed by the authors and suitably restated, has been implemented on a microprocessor-based device that can be installed at each MV/LV substation. The speed and precision of the algorithm have been tested against the errors deriving from the fundamental extraction within the prescribed fault clearing times and against the inherent precision of the electronic device used for computation. The tests have been carried out using Matlab Simulink for simulating the faulted system.

The effect of the distribution of Al atoms in the framework of H-ZSM-5, controlled by zeolite synthesis, on the product yields in 1-butene conversion to low olefins, aromatics and paraffins has been investigated for a series of zeolites, both synthesized and commercial, with Si/Al ranging from 12.6 to 43.6. The 27 Al and 29 Si MAS NMR of the corresponding Na-ZSM-5 and their exchange capacities for Co(II) ions and quantitative analysis of d–d transitions of bare Co(II) ions in the dehydrated CoNa-ZSM-5 were used for determination of the population of the [Al O (Si O) n Al] sequences in the framework. The Si Al sequences with n = 1 were not present in the synthesized or commercial samples. The exchange capacity of Co(II) ions corresponded to the concentration of “close” framework Al atoms present mostly in the six-membered framework rings ( n = 2 ) of the cationic sites. The concentration of “single” Al atoms was calculated from the difference between the total concentration of Al and twice the concentration of the exchanged Co(II) ions. The enhanced formation of aromatics in 1-butene conversion for H-ZSM-5 with similar Si/Al ratio, but higher concentration of “close” Al atoms in the framework is accounted for enhancing the rate of hydrogen transfer reactions, in contrast to samples with higher concentration of “single” Al atoms, where olefin cracking is preferred. As low-temperature (20 K) IR analysis of adsorbed hydrogen showed that the acid strength of the protonic sites in the H-ZSM-5 samples is very similar, the differences in the selectivity of 1-butene cracking and aromatization are thought to be caused by different distribution of framework Al atoms and thus also of the protonic sites. This finding opens a new potential for advanced tailoring of zeolite catalyst selectivity.

The Cr(II)/SiO2 system was found to be able to activate and polymerize at room temperature not only light olefins (such as ethylene and propylene), but also a cyclic molecule such as ethylene oxide, which does not contain a C–C unsaturation. The polymerization of ethylene, propylene and ethylene oxide on the Cr(II)/SiO2 system have been followed in situ by means of temperature- and pressure-resolved FTIR spectroscopy. This method allowed to “freeze” the precursors of the reaction and the intermediate species, even when their amount is low in comparison with spectator species, and in some cases to determine the initiation mechanism. Information about the energy barrier associated with the polymerization reaction (temperature at which the reaction starts) and about the kinetic of the process (time dependence of the experiment) have been obtained in the three cases.

IR spectroscopy of adsorbed probe molecules is one of the most powerful characterization techniques for the investigation of surface active sites on high surface area materials like oxides and zeolites. In the last 20 years the use of specific IR cells allowing the in situ sample activation, gas dosage and sample cooling down to liquid nitrogen temperature has remarkably improved the number and the quality of the information on the surface structure with respect to the first experiments carried out at room temperature. Commercial cryostats able to reach liquid helium temperatures are available since decades, but the incompatibility of the materials used to reach and confine very low temperatures with the high temperatures usually needed to activate the surfaces of catalysts has prevented for long time the breaking down of the 77 K frontier in IR experiments of species adsorbed on active surface sites. In our group we have very recently designed, realized and tested a new experimental set-up able to perform IR experiments in the 15–300 K interval on samples previously activated under vacuum conditions ( P −4 Torr, 1 Torr ∼ 133.3 Pa), or in the desired atmosphere, up to 1073 K [G. Spoto, E.N. Gribov, G. Ricchiardi, A. Damin, D. Scarano, S. Bordiga, C. Lamberti, A. Zecchina, Prog. Surf. Sci. 76 (2004) 71]. The first results obtained with this innovative instrument will be reviewed and summarized in this work and compared with previous literature results on similar experiments performed at liquid nitrogen temperature. In particular, we will discuss the adsorption of CO and H 2 on MgO and H-SSZ-13 zeolite, and of H 2 on Cu + -ZSM-5 zeolite.

The aim of the work was to evaluate the influence of the filler size and shape in the final architecture of biomimetic composite produced through the freeze casting technique.Different samples of ceramic infiltrated with resin, composed by a different ratio between RonaFlair White Sapphire aluminium oxide powder - EMD Chemicals/Rona Gibbstown, USA (platelet-like morphology and average particle size16 µm) and Almatis alumina filler ‑ CT3000SG, Almatis, USA (average particle size of 0.8 µm) have been produced. The samples have been then characterized through thermal analysis and calorimetry (Model TG/DT A 6300, Seiko Instruments USA Inc. Torrance, CA, USA), scanning electron microscopy (Phenom-World BV, Eindhoven, The Netherlands), and optical microscope (Nikon Eclipse E600 microscope). Moreover the percentage of shrinkage after the ceramic sintering have been measured through a digital calibre (Mitutoyo USA, Aurora, IL, USA). Four different groups have been considered: Group 1 (10R): 10% RonaFlair- 90% Almitas; Group 2 (20R): 20% RonaFlair- 80% Almitas; Group 3 (40R): 40% RonaFlair- 60% Almitas; Group 4 (60R): 60% RonaFlair- 40% Almitas.Optical microscope and SEM observations have confirmed that all samples were characterized by a biomimetic hierarchic structure. For what concerning the average thickness of lamellae measured at 4 and 8 mm from the cooling plate, samples 10R were characterized by higher thickness at both levels. The measured parameter indeed decreases with the increment of the percentage of RonaFlair in the slurry composition. On the contrary the distance between lamellae (wavelength), was characterized by an opposite trend. The measurement of the diameters of the samples after the sintering process through a digital calibre has shown that 10R and 20R samples were characterized by a constant shrinkage in all the samples. On the contrary, groups 40R and 60R were distorted and were characterized by a higher diameter at the bottom respect the upper portion of the samples. Indeed these samples were characterized in the bottom by a greater amount of particles, both Almatis than RonaFlair ones. We have supposed that gravity force, during the freeze casting process, tended to push down in the lower layers all heaviest particles and then the lightest ones have occupied the spaces they have left. Consequently in upper layers there were only few particles so during the sintering process were characterized by the higher shrinkage. This phenomenon was limited in samples 10R and 20R because the percentage of greatest particle was so much inferior that their position was not influential.The present study has shown that samples composed by a higher percentage of RonaFlair, were characterized by a higher distortion after sintherization; the cause of this phenomenon could be the different sedimentation process that characterizes particles of different weight and size.

The present work reports the synthesis of trans-2-amino-5(6)-fluoro-6(5)-hydroxy-1-phenyl-2,3-dihydro-1H-indenes (4a-f, 5a-f) as a continuation of our studies to better understand the significance of the halo substituent in the trans-1-phenyl-2-aminoindane series and to extend knowledge of the monophenolic ligands of DA receptors. The affinity of the new compounds and related methoxylated precursors (10-15 and 18-23) was estimated in vitro by displacement of [(3)H]SCH23390 (for D(1)-like receptors) or [(3)H]YM-09-151-2 (for D(2)-like receptors) from homogenates of porcine striatal membranes. The results indicate that unsubstituted amines 4a, 5a, 10, and 11 are poorly effective at DA receptors. The introduction of two n-propyl groups on the nitrogen atom (compounds 14, 15, 4c, and 5c) and N-allyl-N-methyl- or N-methyl-N-propyl- substitution (compounds 20-23, 4e, 4f, 5e, 5f) increased the D(2)-like affinities and selectivity. The D(2)-like agonistic activity of selected compounds 15, 20, 21, 4e, 5c, and 5e was proved by evaluating their effects on the cyclic guanosine monophosphate (cGMP) content in rat neostriatal membranes. All tested compounds displayed a potential dopamine D(2)-like agonist profile decreasing basal levels of cGMP. The selective D(2)-like agonism of compounds 20 and 5e was proved by their effects on basal striatal adenylyl cyclase activity.

We report about the characterization of an isomorphously substituted Fe-MCM-22 sample with high iron content (Si/Fe = 18) using FTIR, XANES and EXAFS spectroscopies. Template burning and subsequent activation in vacuo caused the migration of a fraction of framework Fe 3+ species to extraframework positions, accompanied by the reduction of a fraction of Fe 3+ to Fe 2+ . A fraction of extraframework Fe 2+ sites was able to adsorb NO, forming Fe 2+ (NO) n complexes ( n = 1 , 2 , 3 ), which indicates a high coordinative unsaturation of such sites. The parallel experiment monitored by X-ray absorption spectroscopies testified that this fraction is however small, as both EXAFS and XANES spectra were almost unperturbed by NO adsorption. The corresponding FTIR bands are highly broad and asymmetric, which does not allow to detect the presence of Fe 3+ (NO) complexes. The broad character of the nitrosyl bands suggests the presence of small oxidic clusters, in agreement with XANES and EXAFS evidences. The nature and distribution of extraframework Fe species are influenced by water preadsorption, which causes the increase of the amount of the most coordinatively unsaturated Fe 2+ sites, able to form Fe 2+ (NO) 3 complexes. The effect of red–ox treatments with O 2 and H 2 was also investigated. Upon oxidation, adsorbed oxygen is formed, which efficiently shields the Fe centers and does not rapidly nor efficiently react with NO. Upon reduction, the intensity of nitrosyl complexes increases, indicating the reduction of extraframework Fe 3+ (likely present on the surface of small oxidic clusters) to Fe 2+ . Comparison with the most investigated Fe-MFI system is made.

In this paper an XRD, FTIR and TPD investigation of NO2 surface adsorption sites of δ, γ Al2O3 and barium supported δ, γ Al2O3 is reported. Aim of this study is to bring additional light on the surface structures involved in NOx adsorption. Two samples of barium supported aluminas have been prepared and aged at 800 °C. These samples were characterised in comparison with the relative alumina support. The XRD characterisation of these samples shows the presence of barium carbonate and barium aluminate supported on alumina. The comparison of the FTIR spectra, before and after NO2 adsorption, has revealed the formation, upon NO2 contact, of a complex variety of nitrate and nitrite groups. The thermal desorption of nitrate and nitrite species has been simultaneously studied by means of FTIR spectroscopy and by TPD technique.

A statistical analysis of the infrared data obtained upon absorption of NO on a large number of Al-free Fe-silicalite and Fe-ZSM-5 samples highlighted the influence of Al on the formation and stabilization of extraframework iron species and shed more light on the superior activity of Fe-ZSM-5-based catalysts. It was concluded that Al favors the dispersion of extraframework iron species and that isolated Fe II species with one or two Al atoms in the immediate vicinity are the active sites in partial oxidation reactions. The structure of the α -oxygen species adsorbed on iron centers is also briefly discussed.

As is well known, the Cr2+/SiO2 system is an efficient catalyst for ethylene polymerisation already at RT (even if in the industrial process the running temperature is ∼380 K). For this reason it is the ideal system for in situ spectroscopic investigations on a genuinely working catalyst (Adv. Catal., 2001, 46, 265). Many questions are still uncertain as to the initiation, propagation and termination steps of the polymerisation mechanism. On a pre-reduced sample polymerisation commences very quickly and there is no way to record initial stages. When the experiments are performed at RT the phenomenon is too fast and IR spectroscopy, even in the time-resolved mode, failed up to now in the identification of the species formed during the initiation of the ethylene polymerisation step on the Cr2+/SiO2 Phillips catalyst. We present results related to time-resolved FTIR spectroscopy at variable temperature of acetylene and methylacetylene oligomerisation on a model Phillips catalyst. These experiments have been highly informative on the nature of the active sites because we have observed that acetylene and methylacetylene result in the immediate formation of benzene and 1,3,5-trimethylbenzene, respectively, without the evidence of any measurable intermediate product. This implies that the active Cr sites are able to coordinate simultaneously three monomers and thus must exhibit a high unsaturative coordination. The results of these experiments could be an insight of chromium species active in the Phillips catalyst.

A complete catalytic cycle was performed on CuCl2/Al2O3 catalyst for ethylene oxychlorination at 500 K. X-ray absorption near-edge spectroscopy, extended X-ray absorption fine structure, electron paramagnetic resonance, and IR of adsorbed CO were used to demonstrate that the ethylene oxychlorination reaction, C2H4+2HCl+1/2 O2→C2H4Cl2+H2O, follows a three-step mechanism: (i) reduction of CuCl2 to CuCl (2CuCl2+C2H4→C2H4Cl2+2CuCl), (ii) oxidation of CuCl to give an oxychloride (2CuCl+1/2 O2→Cu2OCl2), and (iii) closure of the catalytic circle by rechlorination with HCl, restoring the original CuCl2 (Cu2OCl2+2HCl→2CuCl2+H2O). The dispersing/sintering effect of the different reagents on the active phase has been also investigated.

Objectives The goal of this work is to evaluate the association between organoleptic scores, oral condition and salivary β-galactosidases, to facilitate the differential diagnosis of halitosis in children. Methods Fifty systemically healthy children with a primary complaint of oral malodour were included in this cross-sectional study. The organoleptic evaluation was carried out by two judges, evaluating the intensity of malodour of the air exhaled 5 s through the mouth of the patients, at a distance of approximately 10 cm from their noses; the level of salivary β-galactosidases was quantified spectrophotometrically after a chromatic reaction between a salivary sample of each patient and a specific chromatic substrate of the enzyme. Clinical conditions, such as visible plaque and gingival bleeding index, tongue coating score, localized food stagnation and other oral parameters, were evaluated by qualified dentists through an oral check-up. Results The β-galactosidase level was significantly related to the organoleptic scores and clinical parameters, such as the tongue coating score and the visible plaque index. Stratifying results with respect to the different phase of the day at which parents complained halitosis in their children, statistical analysis showed that the organoleptic scores and the level of β-galactosidases were significantly higher in children who suffered of halitosis during the whole day, A = 40%, with respect to those without this problem, N = 20% (P = 0.001 and P = 0.006, respectively). Conclusions Certain oral parameters such as halitosis during the whole day, high tongue coating score and high visible plaque index were particularly associated with an increase in the salivary β-galactosidase level.

Adsorption of dihydrogen, carbon monoxide and methane, and co-adsorption of H2/CO, H2/CH4 and CO/CH4 on zinc oxide was studied by means of Fourier transform infrared spectroscopy. Besides the already known dissociation of dihydrogen and molecular adsorption of CO, methane was found to be adsorbed molecularly on coordinatively unsaturated Zn2+ ions. Adsorption lowers the CH4 symmetry from Td to C3v, which is reflected in activation of the v1 (symmetric stretching) mode and discrete frequency shifts of the v3 (antisymmetric stretching) and ν4 (bending) modes. Co-adsorption of the above gases on ZnO having pre-adsorbed hydrogen results, in all cases, in a bathochromic shift of the v(Zn–H) band and a hypsochromic shift of the v(O–H) band, which originally appear at 1710 and 3492 cm−1, respectively. The magnitude of these shifts depends upon the nature of the co-adsorbed gas.

After a brief overview of the reasons why, in spite of the high fraction of framework Ti(IV) atoms, Engelhard titanosilicate (ETS-10) cannot be used as competitive catalyst in partial oxidation reactions, we draw the attention on the fact that the high cation density of ETS-10 can be the key property for potential new catalytic applications of this recent material. Among all, cation exchange with Cu2+ can yield to Cu-ETS-10, a promising material for environmental catalysis. We so present a detailed characterization of this material using N2, CO and NO as probe molecules. In spite of the rather high complexity of the obtained spectra, a comparison with similar experiments (described in the literature or ad hoc performed for this work) on other Cu-exchanged zeolites and on Cu2O dispersed on silica and on MCM-41, allows a full interpretation of the spectroscopic properties. It is shown that copper is present both as counterion and in the form of Cu2O nanoclusters dispersed in the ETS-10 channels and in the external surface. Finally, IR spectroscopy has been used to demonstrate that Cu-ETS-10 is active in the decomposition of NO.

FTIR and diffuse reflectance UV–Vis spectroscopies were used to investigate the nature of the extra-framework iron species in Fe-Silicalite using NO as probe molecule. After removal of the template at 773 K, ferrous species present in two different coordinative states, namely Fe A 2+ and Fe B 2+ , were mainly detected. The Fe A 2+ species are highly coordinatively unsaturated and can form a [Fe A (NO) n ] 2+ (with n >2) polynitrosyl complex characterized by IR bands at 1914, 1880–1850, and 1808 cm −1 and by an electronic transition at 23,000 cm −1 . Upon reducing the NO pressure, this complex is transformed into a [Fe A (NO) 2 ] 2+ dinitrosyl characterized by a doublet of IR bands at 1839 and 1765 cm −1 . Fe B 2+ is less coordinatively unsaturated and forms only [Fe B (NO)] 2+ mononitrosyl (absorbing in the IR at 1839 cm −1 and at 26,500 and 17,500 cm −1 in the UV–Vis). Upon dosage of H 2 O, the Fe B 2+ species becomes able to uptake further NO ligands to give new polynitrosyl species spectroscopically indistinguishable from those formed on the Fe A 2+ species. Based on these results, some hypotheses about the structure of Fe A 2+ and Fe B 2+ are advanced.

The effect of aging and heating treatments up to 500 K on alumina-supported CuCl2, i.e., the base catalyst for ethylene oxychlorination, has been investigated by UV‐vis spectroscopy, a solubility test, EXAFS, XRD, and EPR in a wide range (0.25‐9 wt%) of Cu concentration. It is shown that the catalyst undergoes significant changes with both time and thermal treatments, so accounting for some contradictory results reported in the literature. While the surface Cu aluminate (formed during impregnation) does not change upon aging and heating, supported CuCl2 (precipitated from impregnating solution during the drying process) undergoes a slow hydrolysis reaction with the formation of paratacamite and HCl. The HCl formed during the hydrolysis reacts with the alumina surface with the formation of >Al‐Cl species. Upon heating, the initially formed paratacamite can react with surface >Al‐Cl species with nearly total restoration of CuCl2, which is consequently the main species present on the catalyst at the beginning of the oxychlorination reaction. The obtained picture is able to explain the results emerging from activity tests on the whole set of catalysts, indicating that surface aluminate is not active and that the active phase is CuCl2. c ∞ 2000 Academic Press

A complete innovative measurement system (D2SI - device for the diagnosis of insulation systems) for both acquisition, analysis and processing of partial discharge signals generated in insulation systems under voltage stress (IEC standard), was designed and realized; several measurements on practical insulation systems demonstrated the full and correct equipment operation.

IR and XAFS have been employed to investigate the local environment of Cu 1 in Cu 1 -ZSM-5 prepared by gas phase reaction of H-ZSM-5 with CuCI. Both XAFS and IR measurements show that copper species are momodispersed Cu ions occupying highly unsaturated sites easily accessible to small ligand molecules. Cu 1 -ZSM-5 prepared in this way represent a model solid for investigating the structure of isolated Cu I sites in zeolites. EXAFS analysis reveal that, in vacuum conditions, Cut cations are surrounded by 2.5 ± 0.3 oxygens at 2.00 ± 0.02 A. The combined use of EXAFS, IR and computer graphic simulations allows to infer that Cu I ions in Cu I -ZSM-5 are located in two families of sites.

Purine nucleotide degradation products have been determined by HPLC in aqueous humor obtained during cataract surgery and from plasma of 22 patients (12 women). Uric acid, cytosine, guanosine monophosphate, uracyl, guanine, adenosine, adenosine monophosphate, thymine, adenine, inosine, cyclic guanosine monophosphate, hypoxanthine and xanthine were evaluated. Uric acid and the last two were the only compounds detectable in measurable amounts in aqueous humor and in plasma of all patients. Aqueous humor xanthine levels were not significantly different from plasma; aqueous humor hypoxanthine concentrations were lower than those of xanthine and than plasma oxypurine levels. In 8 patients, treated with allopurinol, oxypurinol concentrations in aqueous humor and in plasma were comparable suggesting that oxypurines are transported through the blood-aqueous humor barrier.

Bamifylline was found to be a poor inhibitor of 3′,5′-cyclic GMP phosphodiesterase (PDE V) as other methylxanthines such as teophylline and caffeine. The IC50was respectively 3.24, 2.91, 1.69 mM. Inhibition decreased at higher cGMP concentrations. Lineweaver-Burk plots were linear or nearly linear. Differences in the actions of these inhibitors presumably reflect differences in the molecular requirements for effective interaction at the catalytic site on phosphodiesterase.

The recently introduced ultrasonic osteotome procedure is an alternative to conventional rotatory burs. The aim of this study was to establish the differences between two ultrasonic osteotomes and conventional rotatory burs, in order to perform micromorphological and histological analyses of osteotomized bone surfaces. Bony samples were taken from adult bovine ribs including both the cortical and marrow bone. Soft tissues have been removed and the bone pieces were divided into four groups, to test four devices: a conventional osteotomy round bur, a Lindeman bur and piezoelectric osteotomes ES007 and the T-Black. Each device performed cuts that were examined via scanning electron microscope (SEM) and light microscopy (LM) to check respectively cut precision and bone architecture all along the defect borders. SEM analysis of specimens showed that burs created defects of greater width and with irregular edges while those produced by ultrasonic osteotomes were narrow and had mostly smooth cutting surfaces. The edges of incisions made by drills were full of bone fragments while less bone chips were observed on piezoincision’s ones. Dimensions of fragments were wider if cuts were made by burs too. LM analysis of samples showed focally, delicate bony trabecules crushed and pressed into the bone marrow in cutting made by burs. Samples cut by ultrasonic devices showed small or no smear layer and only partial or no crushed trabecules. Osteocytes seemed to be intact all along the cutting surface in all samples observed. In the present study, according to literature, ultrasonic surgery validity is confirmed. As a matter of fact, the greater the number of bone chips products, the greater the magnitude of the inflammatory process induced, as well as the possibility of a greater bone loss and delay in wound healing near the osteotomized area.

The aim of this work is to examine the behaviour of laser treated gutta-percha (a–b) after heating, to test the validity of a new obturation technique. Samples of laser- and no laser- treated gutta-percha have been examined by the thermal/thermogravimetric analysis and compared. All samples have been submitted to four runs of heating from the temperature of 25–130 C, followed by spontaneous cooling. It was found that some samples have shown the typical behaviour of the alpha-gutta-percha; others have shown characteristics similar to the conventional beta-gutta-percha. The laser treated gutta-percha has shown a significant mass loss after the first run of heating, while the mass tends to stabilize after the third run. It has been demonstrated that the 980 nm diode laser used with cited parameters does not alters thermal behaviour of gutta-percha cones.

Two series of pumice-supported palladium catalysts (W = washed, U = unwashed) were prepared by the reaction of [Pd(C{sub 3}H{sub 5}){sub 2}] with the support, followed by reduction using H{sub 2}. W catalysts were washed before reduction to eliminate unreacted [Pd(C{sub 3}H{sub 5}){sub 2}]. U catalysts did not undergo this treatment. Microstructural characterization of the catalysts was performed by small-angle X-ray scattering (SAXS), wide-angle X-ray line broadening, and transmission electron microscopy (TEM). Line-broadening analysis revealed the presence of lattice imperfections, such as growth stacking faults and microstrains in the fcc structure of palladium. The average particle size values determined by SAXS were confirmed by TEM analysis and were employed to calculate the percentage of palladium exposed (catalyst dispersion). W catalysts showed well-dispersed spheroidal particles, whereas the U series displayed agglomerates. 38 refs., 9 figs., 2 tabs.

Reactive Hydride Composites (RHCs), ball-milled composites of two or more different hydrides, are suggested as an alternative for solid state hydrogen storage. In this work, dehydrogenation of 2NaBH 4 + MgH 2 system under vacuum was investigated using complementary characterization techniques. At first, thermal programmed desorption of as-milled composite and single compounds was used to identify the temperature range of hydrogen release. RHC samples annealed at various temperatures up to 500 °C were characterized by X-ray diffraction, infrared spectroscopy and scanning electron microscopy. It was found that the dehydrogenation reaction under vacuum is likely to proceed as follows: 2NaBH 4 + MgH 2 (>250 °C) → 2NaBH 4 + 1/2MgH 2 + 1/2Mg + 1/2H 2 (>350 °C) ↔ 3/2NaBH 4 + 1/4MgB 2 + 1/2NaH + 3/4Mg + 7/4H 2 (>450 °C) → 2Na + B + 1/2Mg + 1/2MgB 2 + 5H 2 . In addition, presence of NaMgH 3 phase suggests the occurrence of secondary reactions.

FTIR spectroscopy was applied to study the initial steps of ethylene polymerization on reduced chromia-silica (0.5 wt% Cr/SiO2). To decrease the speed of the reaction small doses of gas were introduced to the catalyst in each run and C2D4 was used to confirm band assignments. At the initial steps of the reaction only ethylene molecules coordinated to probably CrA2+ cations were observed. The concentration of such complexes was estimated to be about 50% of the total amount of Cr atoms in the sample. The FTIR spectrum of the polymer formed at the initial doses of C2H4 (when [C2H4] ≈ [Cr]) was found to be slightly different from that formed after excess ethylene was introduced onto the catalyst ([C2H4] > [Cr]).

The interaction of Cr(CO)6 with polycrystalline α-Cr2O3 has been studied by the use of FTIR spectroscopy. Comparison with previous results for the Cr(CO)6/γ-Al2O3 system shows that the metal carbonyl is adsorbed via O-bonding between a CO ligand and Cr3+ ions coordinatively unsaturated at the surface of the α-Cr2O3 support (which act as Lewis acid centres). Time-resolved spectra show that the original surface adduct undergoes partial decarbonylation. Subcarbonyl species thus formed remain anchored to the oxide support. This behaviour contrasts with that found for the Cr(CO)6/γ-Al2O3 system where no decarbonylation was observed under similar experimental conditions. It is proposed that the high decarbonylating activity of α-Cr2O3 could be related to a possible formation of metal-metal bonds between Cr3+ ions at the oxide surface and chromium atoms of the metal carbonyl.

The aim of this study is to test the response of bone during cutting actions in dental procedures by sampling alkaline phosphatase (ALP) as a biological reference marker. ALP is found abundantly in bone tissue. In the first series of experiments a temporal-minimum quantity of ALP enzyme response was recorded, the observed period was 40 minutes. The ALP samples treated with piezoelectric surgery showed a rapid increase, with peak at 30 min, and then declined rapidly within the next 10 minutes. A second experiment was performed to evaluate 4 cutting instruments: drill bits high speed turbine (T1); drill bits contra-angle (T2) Piezoelectric insertions (T3), and manual instruments (controls). This second experiment was to evaluate the ALP activity at 30 min. The T1 samples produced the highest results (3,66499 +- 0,51394); control groups had a lower response (0,72793 +- 0,22353), while the T2 group produced statistically significant higher results (2,77793 +- 0,40553) than T3 (1,16608 +- 0,32676). The different values obtained for ALP in these two experiments for a short period of time (30 min) cannot be interpreted as a response of bone tissue regeneration subjected to surgical trauma. The MINIMUM trauma caused by the surgical piezoelectric instruments, in respect to conventional surgical instruments is clearly evident from the phosphatase inflammatory activity.

Adsorption of H2 at 20 K on (Na,K)ETS-10 is studied by means of infrared spectroscopy and molecular mechanics simulations. The occurrence of three steps is evidenced, consisting of: (i) specific interaction of H2 with extraframework cations; (ii) aspecific interaction with the channel walls and (iii) pore-filling by a liquid-like phase. Spectroscopic evidence is also given that (Na,K)ETS-10 promotes ortho-para conversion of the adsorbed H2 species.

The aim of this study was to evaluate differences of cGMP-PDE activity in salivary glands, between a control group and different benign tumour groups and, where present, with malign tumour groups. Endogen cGMP was evaluated too. The enzymatic reaction used the method of Spoto et al., with minor variations. The samples were organized in six groups: A (Adenolymphoma and Warthins tumour); B (Pleomorphic Adenoma); C (Basaloid Adenoma); D (Myoepitelioma). The control group was represented by healthy patients. In A and B groups, we have analyzed malign pathologies (Adenocarcinoma and Parotid Lymphoma) The benign tumours have more activity than controls, especially in Myoepitelioma (D) but with a decrement in the C group, which presents lower values of cGMP than the other three groups, where the concentration is similar. Between A and B groups, the activity values of malign tumours are similar, higher than controls and than the other benign pathologies, but not higher than in myoepitelioma. The cyclic concentration is similar for malign pathologies, with concentrations lower than controls, similar to Basaloid Adenoma (C).

Phosphodiesterase activity was tested on homogenized eyes of pre-diabetic rats kept in normoxic, hypoxic and hyperoxic conditions, with the aim of correlating any difference in PDE activity with variations in atmospheric oxygen contents. The activity of the cAMP phosphodiesterase (cAMP-PDE) was tested. Phosphodiesterases seem to be particularly susceptible to variations in oxygen tension, suggesting an important role of cyclic nucleotides in adaptive processes of the cell. cAMP-PDE activity increases slightly in normoxic, hypoxic and hyperoxic conditions in pre-diabetic rats. The second messenger, cAMP, plays important roles in mediating the biological effects of a wide variety of first messengers. The intracellular levels of cyclic nucleotides depend upon rates of synthesis and degradation, of cyclases and phosphodiesterase (PDEs), respectively. Therefore, PDEs seem to play an important role in a wide variety of physiological processes.

Cyclic AMP phosphodiesterase (cAMP PDE) seems to be important in pulp tissues. High levels of cAMP PDE have been demonstrated to be in dental pulp cells. In the present study cAMP PDE activity was analyzed in normal healthy human dental pulps, in reversible pulpitis and in irreversible pulpitis. Enzymatic cAMP PDE control values for normal healthy pulps were 12.14 +/- 3.74 nmols/mg of proteins. In reversible pulpitis the cAMP PDE activity increased almost 2.5 times. In irreversible pulpitis specimens the values increased 4.5 times compared with normal healthy pulps activity. The differences between the groups (control vs. reversible pulpitis and vs. irreversible pulpitis) were statistically significant. These results could point to a role of cAMP PDE in the initial pulp response after injury.

Cyclic GMP phosphodiesterase (cGMP PDE) plays an important role in pulp tissues. High levels of cGMP PDE are found in dental pulp cells. In the present study cGMP PDE activity was analyzed in normal healthy human dental pulps, in reversible pulpitis and in irreversible pulpitis. Enzymatic cGMP PDE control values for normal healthy pulps were 4.74+/-0.32 nmol/mg of proteins. In reversible pulpitis the cGMP PDE activity increased almost 3 times. In irreversible pulpitis specimens the values increased 4.5 times compared with the normal healthy pulps activity. The differences between the groups (control vs. reversible pulpitis and vs. irreversible pulpitis) were statistically significant. These results point to a role of cGMP PDE in the initial pulp response after injury.

Phosphodiesterase activity was tested on homogenized eyes of pre-diabetic rats kept in normoxic, hypoxic and hyperoxic conditions, with the aim of correlating any difference in PDE activity with variations in atmospheric oxygen contents. The activity of the cGMP phosphodiesterase (cGMP-PDE) was tested. Phosphodiesterases seem to be particularly susceptible to variations in oxygen tension, suggesting an important role of cyclic nucleotides in cellular adaptive processes. cGMP-PDE activity increases lightly in normoxic, hypoxic and hyperoxic conditions in pre-diabetic rats. The second messenger, cGMP, plays important roles in mediating the biological effects of a wide variety of first messengers. In particular, cGMP in the eye is an important mediator for the mechanism of sight. The intracellular levels of cyclic nucleotides depend upon the rates of synthesis and degradation, actuated, respectively, by cyclases and phosphodiesterases (PDEs). Therefore, PDEs seem to play an important role in a wide variety of physiological processes.

Several different procedures are available for the immobilization of proteins on solid supports, as many advantages derive from this approach, such as the possibility to develop new protein solid-state assays. Enzymes that are anchored on gold surfaces can interact with several different molecules in a tag-free environment, opening the way to surface plasmon resonance (SPR) investigations. Nevertheless, it is often important to know the identity of the affinity-retained analyte, and mass spectrometric analysis, via its unique molecular mass identification, represents a very valuable complementary method. There are many pieces of evidence to suggest that matrix metalloproteinases (MMPs) are involved in normal and pathological processes, including embryogenesis, wound healing, inflammation, arthritis and cancer, but presumably also exhibiting other functions. The search for new inhibitors of MMPs has prompted research towards the development of new solid-state assays for the rapid evaluation of MMP activity. We have already reported the possibility of measuring the activity of MMP-1 anchored on solid support by coupling SPR with ESI-MS analysis. In this work, we show the in situ atmospheric pressure (AP) MALDI-MS characterization of MMPs anchored on a gold chip with known surface coverage. The study extends the MS analysis to different proteins, and sequence coverage is reported for different digestion and MS procedures.

By diluting optically opaque carbon-supported Pd particles in silica Aerosil® we succeeded in observing the IR bands of adsorbed carbonyls and extracting information on the particle dispersion. Comparison with literature single crystal data and with silica–alumina supported Pd allowed us to make an assignment in terms of linear and 2-fold bridged carbonyls formed on Pd(111) and Pd(100) faces. Two Pd/C samples have been investigated. The relative intensities of the two carbonyl families observed on the two samples are consistent with the Pd dispersion independently measured with CO chemisorption, TEM and EXAFS analysis.