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Environmental contamination by SARS-CoV-2 from patients with COVID-19 undergoing noninvasive ventilation (NIV) in the ICU is still under investigation. This study set out to investigate the presence of SARS-CoV-2 on surfaces near subjects receiving NIV in the ICU under controlled conditions (ie, use of dual-limb circuits, filters, adequate room ventilation).This was a single-center, prospective, observational study in the ICU of a tertiary teaching hospital. Four surface sampling areas, at increasing distance from subject's face, were identified; and each one was sampled at fixed intervals: 6, 12, and 24 h. The presence of SARS-CoV-2 was detected with real-time reverse transcriptase-polymerase-chain-reaction (RT-PCR) test on environmental swabs; the RT-PCR assay targeted the SARS-CoV-2 virus nucleocapsid N1 and N2 genes and the human RNase P gene as internal control.In a total of 256 collected samples, none were positive for SARS-CoV-2 genetic material, whereas 21 samples (8.2%) tested positive for RNase P, thus demonstrating the presence of genetic material unrelated to SARS-CoV-2.Our data show that application of NIV in an appropriate environment and with correct precautions leads to no sign of surface environmental contamination. Accordingly, our data support the idea that use of NIV in the ICU is safe both for health care workers and for other patients.

Verifying the capacity of different types of air filters to stop the propagation of the SARS-CoV-2 virus has become a strategic element to contain viral spreading in enclosed spaces. This paper shows the results of experimental tests about the capacity of different commercial filter grades to stop SARS-CoV-2 propagation using inactivated virions. In the first test, the obtained results showed that the F8 filter blocks SARS-CoV-2 propagation if it encounters a flow devoid of liquid phase, i.e., a biphasic flow that can wet the filtering material. On the contrary, as shown in the second test, the SARS-CoV-2 virus propagates through the F8 filter if the droplet content in the air flow is enough to wet it. In these operational conditions, i.e., when the filter is wet by a flow with a high droplet content, the absolute H14 filter was also shown to fail to stop the transmission of the SARS-CoV-2 virus. Lastly, in the third test, the viral load was shown to be stopped when the pathway of the infected droplet is blocked.

There is substantial agreement that the unbalance between oxidant and antioxidant species may affect the onset and/or the course of a number of common diseases including Parkinson's and Alzheimer's diseases. Many studies suggest a crucial role for oxidative stress in the first phase of aging, or in the pathogenesis of various diseases including neurological ones. Particularly, the role exerted by glutathione and glutathione-related enzymes (Glutathione Transferases) in the nervous system appears more relevant, this latter tissue being much more vulnerable to toxins and oxidative stress than other tissues such as liver, kidney or muscle. The present review addresses the question by focusing on the results obtained by specimens from patients or by in vitro studies using cells or animal models related to Parkinson's and Alzheimer's diseases. In general, there is an association between glutathione depletion and Parkinson's or Alzheimer's disease. In addition, a significant decrease of glutathione transferase activity in selected areas of brain and in ventricular cerebrospinal fluid was found. For some glutathione transferase genes there is also a correlation between polymorphisms and onset/outcome of neurodegenerative diseases. Thus, there is a general agreement about the protective effect exerted by glutathione and glutathione transferases but no clear answer about the mechanisms underlying this crucial role in the insurgence of neurodegenerative diseases.

A mathematical model for the simulation of ENERGIRON direct reduction furnaces has been developed. To simulate the reduction steps an un-reacted shrinking core model has been used. A 1D version of the model has been implemented in a software currently working on an industrial plant, that solves in real time a system of partial differential equations. The outputs of the software are used to foresee the product features at the outlet of the reactor and to take any action needed to improve them. The software also has the capability to adapt itself to the different iron ore mixtures fed to the reactor.

Danieli & C. in collaboration with Politecnico di Milano, designed an innovative, patent pending, treatment plant to solve some issues associated to metals leaching (i.e., Ba, V, and Cr), and high free lime concentration for carbon steel EAF slag, for the production of artificial aggregates featured by mechanical properties suitable for the building purposes. The plant is featured by an innovative pneumatic transport system to convey the stabilizing agent to intercept the molten slag flux during the deslagging operation. The new system promotes stable microstructural phases’ formation, able to retain metallic ions leaching, maintaining the same mechanical properties of the as-cast slag. The main advantages of the new implemented stabilization plant are a simple installation and an easy process operation.

Human glutathione S-transferase P1-1 (hGST P1-1) is involved in cell detoxification processes through the conjugation of its natural substrate, reduced glutathione (GSH), with xenobiotics. GSTs are known to be overexpressed in tumors, and naturally occurring isothiocyanates, such as benzyl isothiocyanate (BITC), are effective cancer chemopreventive compounds. To identify and characterize the potential inhibitory mechanisms of GST P1-1 induced by isothiocyanate conjugates, we studied the binding of GST P1-1 and some cysteine mutants to the BITC-SG conjugate as well as to the synthetic S-(N-benzylcarbamoylmethyl)glutathione conjugate (BC-SG). We report here the inactivation of GST P1-1 through the covalent modification of two Cys47 residues per dimer and one Cys101. The evidence has been compiled by isothermal titration calorimetry (ITC) and electrospray ionization mass spectrometry (ESI-MS). ITC experiments suggest that the BITC-SG conjugate generates adducts with Cys47 and Cys101 at physiological temperatures through a corresponding kinetic process, in which the BITC moiety is covalently bound to these enzyme cysteines through an S-thiocarbamoylation reaction. ESI-MS analysis of the BITC-SG incubated enzymes indicates that although the Cys47 in each subunit is covalently attached to the BITC ligand moiety, only one of the Cys101 residues in the dimer is so attached. A plausible mechanism is given for the emergence of inactivation through the kinetic processes with both cysteines. Likewise, our molecular docking simulations suggest that steric hindrance is the reason why only one Cys101 per dimer is covalently modified by BITC-SG. No covalent inactivation of GST P1-1 with the BC-SG inhibitor has been observed. The affinities and inhibitory potencies for both conjugates are high and very similar, but slightly lower for BC-SG. Thus, we conclude that the presence of the sulfur atom from the isothiocyanate moiety in BITC-SG is crucial for its irreversible inhibition of GST P1-1.

A comparison of the predictions of a rheological model that we recently developed with experimental results of stress and flow profiles in a pilot scale silo is presented in this work. Experiments were performed to collect information on the flow field by means of a tracer method and on wall normal stresses at several different positions along the vessel. The silo (2.5 m high, 0.5 m wide) had the possibility of inserting internal devices; the model was first validated on data without internals and then used to predict the profiles for the case with them. Both stress and flow profiles with and without internals agree with the experimental results within the experimental error that locally could be rather significant due to the difficulty of large scale experiments with granular materials.

The effect of the Y108V mutation of human glutathione S-transferase P1-1 (hGST P1-1) on the binding of the diuretic drug ethacrynic acid (EA) and its glutathione conjugate (EASG) was investigated by calorimetric, spectrofluorimetric, and crystallographic studies. The mutation Tyr 108 --> Val resulted in a 3D-structure very similar to the wild type (wt) enzyme, where both the hydrophobic ligand binding site (H-site) and glutathione binding site (G-site) are unchanged except for the mutation itself. However, due to a slight increase in the hydrophobicity of the H-site, as a consequence of the mutation, an increase in the entropy was observed. The Y108V mutation does not affect the affinity of EASG for the enzyme, which has a higher affinity (K(d) approximately 0.5 microM) when compared with those of the parent compounds, K(d) (EA) approximately 13 microM, K(d) (GSH) approximately 25 microM. The EA moiety of the conjugate binds in the H-site of Y108V mutant in a fashion completely different to those observed in the crystal structures of the EA or EASG wt complex structures. We further demonstrate that the Delta C(p) values of binding can also be correlated with the potential stacking interactions between ligand and residues located in the binding sites as predicted from crystal structures. Moreover, the mutation does not significantly affect the global stability of the enzyme. Our results demonstrate that calorimetric measurements maybe useful in determining the preference of binding (the binding mode) for a drug to a specific site of the enzyme, even in the absence of structural information.

The thermal stability of the Wells–Dawson heteropoly compound K6P2W18O62·10H2O was examined under both reducing and oxidizing conditions, and its structural and morphological evolution was characterized by several complementary solid state techniques. It is shown that the primary structure of the title compound remains intact up to 770 K, while at higher temperature structural changes and rearrangements are observed. These modifications depend considerably on the treatment conditions and catalyst composition. Under oxidizing conditions the Wells–Dawson compound rearranges with formation of a mixed phase containing the Keggin-type unit K3PW12O40 and the hexatungstate K2W6O19. Furthermore, the catalytic activity in the oxidation of isobutane is affected considerably by these changes. The best catalytic performance was shown by the rearranged Wells–Dawson compound.

The structural transformation occurring to a mixture of cubic CeO2 and monoclinic ZrO2 by High-energy Mechanical Milling (MM) has been followed by neutron diffraction. Rietveld analysis indicate that 9 hours of milling produce a tetragonal solid solution for Zr-rich composition and a nanocrystalline cubic solid solution for Ce-rich composition.

The room-temperature high energy ball-milling technique was used to prepare nanophase Ce1-xZrxO2 (x=0; 0.2; 0.5; 0.8; 1) catalysts. The acid–base properties of these catalysts were investigated by means of adsorption microcalorimetry, using NH3 and CO2 as probe molecules. The catalytic activity for 4-methylpentan-2-ol dehydration was tested at atmospheric pressure in a fixed-bed flow microreactor. The inclusion of increasingly high contents of zirconium into the ceria lattice has a complex influence on the acidity and basicity of the pure parent oxide, in terms of both number and strength of the sites. A maximum in 1-alkene selectivity is observed for the ceria-rich catalyst and a minimum for the zirconia-rich sample. Catalytic results are correlated with the acid–base properties and can be interpreted in the light of the mechanism formerly proposed for zirconia, ceria and lanthania. Surface conditioning of the zirconia-rich catalyst occurs during the run, resulting in a remarkable variation of selectivity.

The thermal stability of the Wells-Dawson heteropoly compound K6P2W18O62·10H2 was examined under both reducing and oxidizing conditions, and its structural and morphological evolution was characterized by several complementary solid state techniques. It is shown that the primary structure of this compound remains intact up to 770 K, while at higher temperature structural changes and rearrangements are observed. These modifications depend considerably on the treatment conditions and catalyst composition. Under oxidizing conditions the Wells-Dawson compound rearranges with formation of a mixed phase containing the Keggin-type unit K3PW12O40 and the hexatungstate K2W6O19. Furthermore, the catalytic activity in the oxidation of isobutane is affected considerably by these changes. The best catalytic performance was shown by the rearranged Wells-Dawson compound.

The diuretic drug ethacrynic acid (EA), both an inhibitor and substrate of pi class glutathione S-transferase (GST P1-1), has been tested in clinical trials as an adjuvant in chemotherapy. We recently studied the role of the active site residue Tyr-108 in binding EA to the enzyme and found that the analysis was complicated by covalent binding of this drug to the highly reactive Cys-47. Previous attempts to eliminate this binding by chemical modification yielded ambiguous results and therefore we decided here to produce a double mutant C47S/Y108V by site directed mutagenesis and further expression in Escherichia coli and the interaction of EA and its GSH conjugate (EASG) examined by calorimetric studies and X-ray diffraction. Surprisingly, in the absence of Cys-47, Cys-101 (located at the dimer interface) becomes a target for modification by EA, albeit at a lower conjugation rate than Cys-47. The Cys-47 → Ser mutation in the double mutant enzyme induces a positive cooperativity between the two subunits when ligands with affinity to G-site bind to enzyme. However, this mutation does not seem to affect the thermodynamic properties of ligand binding to the electrophilic binding site (H-site) and the thermal or chemical stability of this double mutant does not significantly affect the unfolding mechanism in either the absence or presence of ligand. Crystal structures of apo and an EASG complex are essentially identical with a few exceptions in the H-site and in the water network at the dimer interface.

We evaluated glutathione transferase (GST) activities and the levels of glutathionylated hemoglobin in the RBC of 42 workers exposed to 1,3-butadiene in a petrochemical plant, using 43 workers not exposed to 1,3-butadiene and 82 foresters as internal and external controls, respectively. Median 1,3-butadiene exposure levels were 1.5, 0.4, and 0.1 μg/m3 in 1,3-butadiene-exposed workers, in workers not directly exposed to 1,3-butadiene, and in foresters, respectively. In addition, we determined in the peripheral blood lymphocytes of the same individuals the presence of GST polymorphic genes GSTT1 and GSTM1 and the distribution of GSTP1 allelic variants. Comparing the mean values observed in petrochemical workers with those of control foresters, we found a marked decrease of GST enzymatic activity and a significant increase of glutathionylated hemoglobin in the petrochemical workers. A weak but significant negative correlation was found between levels of 1,3-butadiene exposure and GST activity, whereas a positive correlation was found between 1,3-butadiene exposure and glutathionylated hemoglobin. A negative correlation was also observed between GST activity and glutathionylated hemoglobin. No influence of confounders was observed. Using a multiple linear regression model, up to 50.6% and 41.9% of the variability observed in glutathionylated hemoglobin and GST activity, respectively, were explained by 1,3-butadiene exposure, working setting, and GSTT1 genotype. These results indicate that occupational exposure to 1,3-butadiene induces an oxidative stress that impairs the GST balance in RBC, and suggest that GST activity and glutathionylated hemoglobin could be recommended as promising biomarkers of effect in petrochemical workers. (Cancer Epidemiol Biomarkers Prev 2008;17(11):3004–12)

Purpose Although clinically evident diabetes-related microvascular complications are extremely rare in childhood, early functional and structural abnormalities may be present a few years after the onset of the disease. Renal Doppler resistance index (RI) is widely used for the evaluation of blood flow in renal parenchymal diseases. This study was designed to investigate the possible alteration of intrarenal Doppler RI in children with diabetes compared with healthy children. Methods The study was performed in 42 children with diabetes (age range, 6–18 years) and in 41 age-matched healthy controls, all having normal renal function. RI was measured with Doppler sonography in interlobular renal arteries. Results RI values were significantly greater in children with diabetes than in age-matched healthy controls (0.64 ± 0.03 versus 0.60 ± 0.04, P < 0.035). RI correlated positively with HbA1c (P < 0.001, r = 0.42) and diabetes duration (P < 0.05, r = 0.39). Conclusion Early changes in renal hemodynamics are detectable on Doppler sonography in children with diabetes without any evidence of renal dysfunction and may suggest a preclinical stage of diabetic nephropathy. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2008.

OBJECTIVE—The aim of the present study was to evaluate serum and urinary nitric oxide (NO) concentrations in children and adolescents with diabetes compared with age-matched healthy control subjects to find out whether Doppler ultrasonography could be used to detect changes in renal resistive indexes (RIs) in children with diabetes and to assess whether there are correlations between these parameters and NO excretion. RESEARCH DESIGN AND METHODS—We studied 42 children with type 1 diabetes and 41 matched healthy control subjects, both divided into prepubertal or pubertal children. Serum and urinary nitrite and nitrate (NO2−+NO3−) concentrations were evaluated as an index of NO production. Doppler ultrasonographic registration of intrarenal RI was performed. RESULTS—Compared with healthy control subjects, children with diabetes had significantly increased concentrations of serum (30.26 ± 6.52 vs. 24.47 ± 7.27 mmol/l, P = 0.001) and urinary NO2−+NO3− (345.07 ± 151.35 vs. 245.86 ± 80.25 mmol/l, P = 0.002); the same was true for Doppler RI values (0.64 ± 0.03 vs. 0.60 ± 0.04, P = 0.035). This occurs in both prepubertal and the pubertal children. A significant positive correlation was found between serum and urinary NO2−+NO3− levels (P = 0.002, r = 0.374). Serum NO2−+NO3− concentrations also correlated positively with Doppler RI (P = 0.032, r = 0.262) and HbA1c (A1C) (P = 0.004, r = 0.329); urinary NO2−+NO3− concentrations correlated positively with A1C (P = 0.001, r = 0.394). Doppler RI correlated positively with A1C (P = 0.000, r = 0.424). CONCLUSIONS—This study demonstrates that in children with diabetes, chronic hyperglycemia may act through a mechanism that involves increased NO production and/or action and contributes to generating intrarenal hemodynamic abnormalities, which are detectable by Doppler ultrasonography even in early diabetic nephropathy.

This study investigates the use of low-temperature catalytic oxidation for the removal of H 2 S from tail gases originating from geothermal plants, with special focus on the effect of water on the overall performance of the activated carbon catalyst. It is shown that water strongly influences the reaction rate and the total amount of sulfur that can be adsorbed on the catalyst prior to regeneration. It is suggested that the reaction takes place in a thin water layer, inside the carbon pores, from the reaction of dissolved H 2 S with chemisorbed oxygen.

The reactivity and characterization of Pd-containing ceria-zirconia catalysts in the combustion of methane is investigated. It is shown that the properties of the mixed-oxide phase play an important role in the behavior of the catalysts in the high-temperature region of the light-off curve. This can be related to the oxygen diffusion features of CeO 2 -ZrO 2 which can help transfer of oxygen to Pd and reduce the detrimental effects of PdO→Pd transformation.

A series of ceria-containing mixed oxides has been prepared and utilized as catalysts in the oxidation of acetic acid in water. The incorporation of even relatively small amounts of ZrO 2 and MnO x or CuO into the fluorite lattice of CeO 2 strongly enhances the redox properties of the material with a consequent promotion of the oxidation activity. The best results are obtained with the ternary mixed-oxides CeO 2 -ZrO 2 -CuO and CeO 2 -ZrO 2 -MnO x which benefit from a synergetic interaction between CeO 2 (whose properties are already modified by the presence of Zr) and CuO or MnO x . Analysis of metal ion concentration in the effluents after reaction indicates also a high stability of the mixed-oxide catalysts under the conditions employed.

Neutron diffraction measurements were carried out on samples of CeO2–ZrO2 powder catalysts prepared by high-energy mechanical milling. The formation of solid solution was evidenced across the entire composition range examined. Quantitative phase evaluation by the Rietveld method indicated formation of tetragonal structure for low CeO2 content, whereas cubic solid solutions were the stable form at high CeO2 loading. In addition, a pseudocubic or tetragonal t″ cell with axial ratio of unity and with internal deformation of the oxygen sublattice was observed at intermediate composition (50 mol% CeO2). Thermal annealing up to 1000 °C showed expansion of the unit cell parameters; an increase in the degree of tetragonality at the expense of cubic and monoclinic phase was observed for composition CexZr1−xO2 (x < 0.5).

The catalytic activity of a series of CeO2–ZrO2 mixed oxides in the total oxidation of methane and light hydrocarbons has been investigated. The influence of dopants like Mn and Cu has also been studied. It is shown that both MnOx and CuO at low loading dissolve within the ceria–zirconia lattice. This strongly influences the redox behaviour of the catalysts by promoting low-temperature reduction of Ce4+. In addition, the ternary oxides show better stability to repeated redox cycles, which is attributed to the presence of ZrO2. The catalytic activity of pure CeO2 is also enhanced in the presence of ZrO2, reaching a maximum with Ce0.92Zr0.08O2; a further promotion of activity is observed with the introduction of MnOx and CuO dissolved into CeO2–ZrO2 lattice.