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31.
B Censori O Manara C Agostinis M Camerlingo L Casto B Galavotti T Partziguian MC Servalli B Cesana G Belloni A Mamoli 《Canadian Metallurgical Quarterly》1996,27(7):1205-1210
BACKGROUND AND PURPOSE: Cognitive deficits may significantly worsen the quality of life after stroke. Our aim was to determine the frequency of dementia in a consecutive series of previously nondemented patients between the ages of 40 and 79 years at 3 months after a first ischemic stroke. METHODS: All patients admitted to our department during an 18-month period who met the above criteria were visited and tested and underwent a CT scan 3 months after their stroke. Dementia was diagnosed according to criteria of the National Institute of Neurological Disorders and Stroke and AIREN, but cases with aphasia were not excluded. RESULTS: Of 304 patients admitted for stroke, 146 were eligible for study. Eleven refused to participate, 25 were dead at 3 months, and 110 were tested. Fifteen patients were demented (13.6%; 95% confidence interval [CI], 7.8% to 21.5%), and six had severe isolated aphasia, neglect, or memory deficit (5.4%). Excluding patients with aphasia, 5.0% of cases showed dementia (95% CI, 1.6% to 11.3%). The frequency of dementia was 24.6% (95% CI, 14.5% to 37.3%), considering only patients with supratentorial lesions and with residual deficits of elementary functions (paresis, sensory deficits) at the time of examination. Demented patients had significantly more diabetes (P<.029), atrial fibrillation (P=.032), aphasia at entry (P<.001), large middle cerebral artery infarctions (P=.001), and a more severe neurological deficit at entry (P=.003) and at 3 months (P=.001). At CT scan, demented patients had a larger mean volume of the recent lesion (P<.001) and more lesions in the frontal lobe (P=.041). An exploratory multivariate analysis selected age between 60 and 69 years (odds ratio [OR], 45.8; 95% CI, 2.9 to 726.0), diabetes (OR 59.4; 95% CI, 4.3 to 821.0), aphasia (OR, 14.8; 95% CI, 2.0 to 111.0), a large middle cerebral artery infarction (OR, 30.0; 95% CI, 2.7 to 334.0), and lesions of the frontal lobe (OR, 9.8; 95% CI, 1.3 to 72.8) as significant independent correlates of poststroke dementia. CONCLUSIONS: Dementia is relatively frequent after a clinical first stroke in persons younger than 80 years, and aphasia is very often associated with poststroke dementia. If aphasic patients are not considered, it may be necessary to screen a very large number of subjects to collect an adequate sample of demented cases. 相似文献
32.
MA Marchisio M Dubini G Serra T Mennini L Manara 《Canadian Metallurgical Quarterly》1976,33(4):269-271
The lipid-lowering effects of 3 g of the nicotinic acid derivative pentaerythritoltetranicotinate (niceritrol) given either 1 g X 3 or 1.5 g X 2 have been evaluated in 18 subjects with hyperlipoproteinaemia. When 1 g niceritrol was given three times daily, the serum TG concentration fell from 3.14 +/- 0.48 to 1.86 +/- 0.18 mmol/1 (41% reduction) and the serum cholesterol concentration from 282 +/- 9 to 227 +/- 11 mg/100 ml (20% reduction). The same daily dose, given 1.5 g twice, did not significantly lower the serum TG concentration, and serum cholesterol was lowered by only 12%. Niceritrol tablets prepared with a dissolution time of 60 or 90 min had identical lipid-lowering properties. Although patients may find it practical to take niceritrol only twice daily, such a dose regimen has considerably less effect on elevated serum lipids than a thrice-daily regimen. 相似文献
33.
Vijayaharan A. Venugopal Giampiero Ottaviani Camillo Bresolin Davide Erbetta Alberto Modelli Enrico Varesi 《Journal of Electronic Materials》2009,38(10):2063-2068
The thermal stability of a Ge2Sb2Te5 chalcogenide layer in contact with titanium and titanium nitride metallic thin films has been investigated mainly using x-ray
diffraction and elastic nuclear backscattering techniques. Without breaking vacuum, Ti and TiN have been deposited on Ge2Sb2Te5 material using magnetron sputtering. Thermal treatments have been performed in a 10−7 mbar vacuum furnace. On annealing up to 450°C, the TiN metallic film does not interact with the chalcogenide film, but at
the same time adhesion problems and instabilities in contact resistance arise. To improve the adhesion and eventually stabilize
the contact resistance, an interfacial Ti layer has been considered. At 300°C, a TiTe2 compound is formed by interacting with Te segregated from the Ge2Sb2Te5 layer. At higher temperatures, the Ti layer decomposes the chalcogenide film, forming several compounds tentatively identified
as GeTe, Ge3Ti5, Ge5Ti6, TiTe2,, and Sb2Te3. It has been found that the properties of the Ge2Sb2Te5 film can be retained by controlling the decomposition rate of the chalcogenide layer, which is achieved by providing a limited
supply of Ti and/or by depositing a Te-rich Ge2Sb2Te5 film. 相似文献
34.
Alessandro Benedetti Luca Magagnin Francesca Passaretti Elisabetta Chelossi Marco Faimali Giampiero Montesperelli 《Electrochimica acta》2009,54(26):6472-6478
Cathodic protection of metals in seawater is known to be influenced by chemical–physical parameters affecting cathodic processes (oxygen discharge, hydrogen evolution and calcareous deposit precipitation). In shallow seawater, these parameters are influenced by sunlight photoperiod and photosynthetic activity. The results presented here represent the first step in studies dedicated to cathodic protection in shallow photic seawater. This paper reports on carbon steel protected at −850 mV vs. Ag/AgCl (oxygen limiting current regime) in the presence of sunlight radiation but in the absence of biological and photosynthetic activity, the role of which deserves future research. Comparison of results obtained by exposing electrochemical cells to daylight cycles in both biologically inactivated natural seawater and in NaCl 3.5 wt.% solutions showed that sunlight affects current densities and that calcareous deposit interfere with light-currents effects. Sunlight radiation and induced heating of the solution have been separated, highlighting results not otherwise obvious: (1) observed current waves concomitant with sunlight radiation depend fundamentally on solar radiation, (2) solar radiation can determine current enhancements from early to late phases of aragonite crystal growth, (3) a three-day-old CaCO3 layer reduces but does not eliminate the amplitude of the current waves. Theoretical calculations for oxygen limiting currents and additional field tests showed that sunlight, rather than bulk solution heating, is the main cause of daily current enhancements. This was confirmed by polarizations performed at −850 and −1000 mV vs. Ag/AgCl (constant bulk temperature), during which the electrode was irradiated with artificial lighting. This test also confirmed O2 discharge to be the cathodic process involved. A mechanism of radiation conversion to heat in the oxygen diffusion layer region is proposed. 相似文献
35.
Francesca R. Lamastra Mehdi Chougan Emanuele Marotta Samuele Ciattini Seyed Hamidreza Ghaffar Stefano Caporali Francesco Vivio Giampiero Montesperelli Ugo Ianniruberto Mazen J. Al-Kheetan Alessandra Bianco 《Ceramics International》2021,47(14):20019-20031
The impact of graphite nanoplatelets (GNPs) on the physical and mechanical properties of cementitious nanocomposites was investigated. A market-available premixed mortar was modified with 0.01% by weight of cement of commercial GNPs characterized by two distinctively different aspect ratios.The rheological behavior of the GNP-modified fresh admixtures was thoroughly evaluated. Hardened cementitious nanocomposites were investigated in terms of density, microstructure (Scanning Electron Microscopy, SEM and micro–Computed Tomography, μ-CT), mechanical properties (three-point bending and compression tests), and physical properties (electrochemical impedance spectroscopy, EIS and thermal conductivity measurements). At 28 days, all GNP-modified mortars showed about 12% increased density. Mortars reinforced with high aspect ratio GNPs exhibited the highest compressive and flexural strength: about 14% and 4% improvements compared to control sample, respectively. Conversely, low aspect ratio GNPs led to cementitious nanocomposites characterized by 36% decreased electrical resistivity combined with 60% increased thermal conductivity with respect to the control sample. 相似文献
36.
Chiara Piccini Giampiero Cai Maria Celeste Dias Mrcia Araújo Sara Parri Marco Romi Claudia Faleri Claudio Cantini 《International journal of molecular sciences》2021,22(20)
In recent decades, atmospheric pollution led to a progressive reduction of the ozone layer with a consequent increase in UV-B radiation. Despite the high adaptation of olive trees to the Mediterranean environment, the progressive increase of UV-B radiation is a risk factor for olive tree cultivation. It is therefore necessary to understand how high levels of UV-B radiation affect olive plants and to identify olive varieties which are better adapted. In this study we analyzed two Italian olive varieties subjected to chronic UV-B stress. We focused on the effects of UV-B radiation on RubisCO, in terms of quantity, enzymatic activity and isoform composition. In addition, we also analyzed changes in the activity of antioxidant enzymes (SOD, CAT, GPox) to get a comprehensive picture of the antioxidant system. We also evaluated the effects of UV-B on the enzyme sucrose synthase. The overall damage at biochemical level was also assessed by analyzing changes in Hsp70, a protein triggered under stress conditions. The results of this work indicate that the varieties (Giarraffa and Olivastra Seggianese) differ significantly in the use of specific antioxidant defense systems, as well as in the activity and isoform composition of RubisCO. Combined with a different use of sucrose synthase, the overall picture shows that Giarraffa optimized the use of GPox and opted for a targeted choice of RubisCO isoforms, in addition to managing the content of sucrose synthase, thereby saving energy during critical stress points. 相似文献
37.
Ferreri C Manco I Faraone-Mennella MR Torreggiani A Tamba M Manara S Chatgilialoglu C 《Chembiochem : a European journal of chemical biology》2006,7(11):1738-1744
The occurrence of tandem damage, due to reductive radical stress involving proteins and lipids, is shown by using a biomimetic model. It is made of unsaturated lipid vesicle suspensions in phosphate buffer in the presence of methionine, either as a single amino acid or as part of a protein such as RNase A, which contains four methionine residues. The radical process starts with the formation of H(.) atoms by reaction of solvated electrons with dihydrogen phosphate anions, which selectively attack the thioether function of methionine. The modification of methionine to alpha-aminobutyric acid is accompanied by the formation of thiyl radicals, which in turn cause the isomerization of the cis fatty acid residues to the trans isomers. The relationship between methionine modification and lipid damage and some details of the reductive radical stress obtained by proteomic analysis of irradiated RNase A are presented. 相似文献
38.
Paolo Rossi Mario Capobianchi Fabio Crescenzi Alberto Massimi Giampiero Mugnaini Aldo Pizzuto Juan Knaster Hannu Rajainmaki 《Fusion Engineering and Design》2012,87(5-6):608-612
After a first R&D and testing activity to develop and characterize by tensile and creep tests a high strength glass fiber-epoxy composite as reference material for the manufacture of ITER pre-compression rings, ENEA designed and manufactured a dedicated testing facility and different sub-scale composite ring mock-ups in order to characterize their mechanical properties.The paper reports the results of the overall testing activities performed during the last years on a total number of eleven sub-scale pre-compression ring mock-ups manufactured by winding S2 glass fibers on a diameter of 1 m (1/5 of the full scale) both by vacuum pressure epoxy impregnation (VPI) and filament wet winding techniques (WW).The first three rings were manufactured by ENEA Frascati thanks to a particular VPI technique; one of them was used as base composite material to manufacture different sets of specimens for shear, compression and non destructive tests (NDT). Then, five other mock-ups were manufactured following ENEA VPI process and three using WW technique by two different industrial companies.The rings were tested in ENEA Frascati in a dedicated hydraulic testing machine consisting of 18 radial actuators working in position control with a total load capability of 1000 tons. The complete testing campaign consisted of six ultimate tensile strength (UTS) tests and four stress relaxation (SR) tests.The tests demonstrated that the composite (S2 glass-epoxy) is a valid and viable solution for the ITER pre-compression rings (non conductive, non magnetic, capable to work at high stress level without relaxation).UTS tests showed an overall average ultimate strength of 1550 MPa (mean hoop stress in the cross section) and a constant hoop modulus to failure of all the mock-ups. Stress relaxation tests did not show any significant relaxation at different stress levels and durations. 相似文献
39.
E. López-Honorato H. Zhang R.A. Shatwell P. Guillermier D. Manara P. Xiao J. Somers 《Journal of Nuclear Materials》2013,432(1-3):334-340
Silicon carbide (SiC) and pyrolytic carbon (PyC) coatings in tristructural isotropic (TRISO) coated fuel particles were characterised by a combination of 2-modulator generalised ellipsometry microscopy (2-MGEM), Raman spectroscopy and transmission electron microscopy. We compared the values of anisotropy obtained from 2-MGEM and Raman spectroscopy to investigate the effect of sampling area and microstructure. No linear correlation in anisotropy was found between these two techniques despite both sampling areas of 2–5 μm. The largest deviations were observed for highly anisotropic samples with optical anisotropy factors (OPTAFs) above 1.1. For medium and low anisotropy samples (OPTAF < 1.1) the relationship is close to linear. The limited use of only the average value of diattenuation does not give an accurate representation of the characteristics of the coatings as significant areas can exist with considerably higher diattenuations that could increase the probability of failure under neutron irradiation. We also observe a change in the diattenuation of SiC due to the presence of stacking faults as confirmed by Raman spectroscopy. Raman spectroscopy was also used to perform semiquantitative analysis of the Si and carbon excess in SiC in four TRISO particles. 相似文献
40.
The aim of this study was to determine ochratoxin A (OTA) concentrations in the raw materials and cooked meat products made from pigs sub-chronically exposed to OTA. The treated animal group (n = 5) was administered with 300 μg OTA/kg of feed for 30 days, whereas the control group (n = 5) was left untreated. OTA concentrations were quantified using immunoassay (ELISA) and high performance liquid chromatography with fluorescence detection (HPLC-FD). OTA concentration was the highest in the kidney, followed by the lungs, liver, blood, spleen, heart, and adipose tissue. As for the final meat products, the highest average OTA concentration was detected in black pudding sausages (14.02 ± 2.75 μg/kg), then in liver sausages (13.77 ± 3.92 μg/kg), while the lowest was found in pâté (9.33 ± 2.66 μg/kg). The results pointed out that a sub-chronic pig exposure leads to the accumulation of OTA in raw materials and consequently in meat products, whose level of contamination is directly dependent on OTA contents in raw materials used for their production. 相似文献