The experiment was focused on comparison of mass loss exhibited by induction-hardened and gas-nitrided samples made of 42CrMo4 steel. The mass loss was caused by abrasive wear, i.e. by motion of the ...abrasive particles. Wear testing was performed with different input parameters (sample velocity and impact angle of abrasive particles and the tested surface). This experiment proceeded with metallographic analysis performed by an optical microscope and by imaging of wear path done by scanning electron microscopy (SEM), to conclude with the statistical analysis of obtained data. The conducted experiment determined that the gas-nitrided samples lost less mass at all levels of input parameters than the induction-hardened samples.
Contamination with total petroleum hydrocarbons (TPH) subsequent to refining activities, is currently one of the major environmental problems. Among the biological remediation approaches, landfarming ...and in situ bioremediation strategies are of great interest. Purpose of this study was to verify the feasibility of a remediation process wholly based on biological degradation applied to contaminated soils from a decommissioned refinery.
This study evaluated through a pot experiment three bioremediation strategies: a) Natural Attenuation (NA), b) Landfarming (L), c) Bioaugmentation-assisted Landfarming (LB) for the treatment of a contaminated soil with petroleum hydrocarbons (TPHs). After a 90-days trial, Bioagumentation – assistited Landfarming approach produced the best results and the greatest evident effect was shown with the most polluted samples reaching a reduction of about 86% of total petroleum hydrocarbons (TPH), followed by Landfarming (70%), and Natural Attenuation (57%). The results of this study demonstrated that the combined use of bioremediation strategies was the most advantageous option for the treatment of contaminated soil with petroleum hydrocarbons, as compared to natural attenuation, bioaugmentation or landfarming applied alone. Besides, our results indicate that incubation with an autochthonous bacterial consortium may be a promising method for bioremediation of TPH-contaminated soils.
•Three approaches of bioremediation for a petroleum hydrocarbons contaminated soil through a plot experiment.•Biodegradation capacity of native microbial community in TPH contaminated soils was evaluated.•Bioagumentation – assistited Landfarming lab tests allowed to achieve, after 90 days, a contaminant reduction up to 80%.
This study is performed to find ways for expanding use in industry of nanocomposites based on a light metal matrix and multiwall carbon nanotubes. Industrial tests are conducted using a high-pressure ...die casting process. Specimens are prepared in two ways using aluminum alloy AlSi
9
Cu
3
(Fe) with maximum specific magnesium content of 0.55 wt.%: by adding 0.2 wt.% of nanotubes directly to molten AlSi
9
Cu
3
(Fe) for the high-pressure die casting process, and by adding 0.05, 0.1 and 0.2 wt.% of nanotubes to the press ahead of the high-pressure die casting process piston. Chemical composition is determined and the effect of magnesium on improved interphase bonding leading to homogeneous distribution of multiwall carbon nanotubes is confirmed. Addition of 0.05 wt.% nanotubes results in a finer specimen microstructure, resulting in improved mechanical properties. Based on research, recommendations are proposed for the industrial scaling up and use of nanocomposites, particularly in automobile components.
Purpose
The objective of our study was to evaluate the presence of respiratory symptoms and chronic obstructive pulmonary disease (COPD) in a human immunodeficiency virus (HIV)-infected outpatient ...population and to further investigate the role of highly active antiretroviral therapy (HAART) and other possibly associated risk factors.
Methods
We consecutively enrolled in a cross-sectional study HIV-infected patients and HIV-negative age, sex and smoking status matched controls. All participants completed a questionnaire for pulmonary symptoms and underwent a complete spirometry.
Results
We enrolled 111 HIV-infected patients and 65 HIV-negative age- and sex-matched controls. HIV-infected patients had a significantly higher prevalence of any respiratory symptom (
p
= 0.002), cough (
p
= 0.006) and dyspnoea (
p
= 0.02). HIV-infected patients also had a significantly higher prevalence of COPD in respect of HIV-negative controls (
p
= 0.008). Furthermore, HIV-infected individuals had significantly (
p
= 0.002) lower forced expiratory volume at one second (FEV1) and FEV1/forced vital capacity (FVC) ratio (Tiffeneau index) (
p
= 0.028), whereas the total lung capacity (TLC) was significantly higher (
p
= 0.018). In the multivariate analysis, significant predictors of respiratory symptoms were current smoking adjusted odds ratio (AOR) 11.18; 95 % confidence interval (CI) 3.89–32.12 and previous bacterial pneumonia (AOR 4.41; 95 % CI 1.13–17.13), whereas the only significant predictor of COPD was current smoking (AOR 5.94; 95 % CI 1.77–19.96). HAART receipt was not associated with respiratory symptoms nor with COPD.
Conclusions
We evidenced a high prevalence of respiratory symptoms and COPD among HIV-infected patients. HIV infection, current cigarette smoking and previous bacterial pneumonia seem to play a significant role in the development of respiratory symptoms and COPD. Thus, our results suggest that the most at-risk HIV-infected patients should be screened for COPD to early identify those who may need specific treatment.
The experiment was focused on comparison of mass loss exhibited by induction-hardened and gas-nitrided samples made of 42CrMo4 steel. The mass loss was caused by abrasive wear, i.e. by motion of the ...abrasive particles. Wear testing was performed with different input parameters (sample velocity and impact angle of abrasive particles and the tested surface). This experiment proceeded with metallographic analysis performed by an optical microscope and by imaging of wear path done by scanning electron microscopy (SEM), to conclude with the statistical analysis of obtained data. The conducted experiment determined that the gas-nitrided samples lost less mass at all levels of input parameters than the induction-hardened samples.
To evaluate the safety and efficacy of long-term glatiramer acetate (GA) therapy, 46 patients with relapsing—remitting multiple sclerosis (RRMS) were treated for up to 22 years in an ongoing, ...open-label study. Kurtzke expanded disability status scale (EDSS) was measured every six months, relapses were reported at occurrence and patients self-reported adverse events (AEs). At GA initiation, disease durations ranged from 0—20 years (median 6.0 years) and at data cut-off (October 2004), GA therapy duration ranged from 1—22 years (median 12.0 years). Mean EDSS score increased 0.9 ± 1.9 from the pretreatment score (3.0 ± 1.8; P = 0.076). Only 10/28 (36%) patients with baseline EDSS <4.0 had a last observed value ≥ 4.0 and 8/34 (24%) with entry EDSS < 6.0 reached EDSS ≥ 6.0. A majority (57%) maintained improved or unchanged EDSS scores. Annualized relapse rate decreased to 0.1 ± 0.2 from 2.9 ± 1.4 prestudy (P < 0.0001). Of the 18 remaining patients in October 2004 (average disease duration 23 years), 17% with baseline EDSS scores < 4.0 reached EDSS ≥ 4.0 and 28% with baseline scores < 6.0 reached EDSS ≥ 6.0. Adverse events were similar to those reported in short-term clinical trials. This study shows a low rate of relapses and EDSS progression in RRMS patients on GA for up to 22 years. Multiple Sclerosis 2008; 14: 494—499. http://msj.sagepub.com
We found Cop 1 to be effective and relatively safe in a previous (exacerbating-remitting) clinical trial. This current trial involves 106 chronic-progressive patients. The major end point, confirmed ...progression of 1.0 or 1.5 units (depending on baseline disability) on the Kurtzke Expanded Disability Status Scale, was observed in nine (17.6%) treated and 14 (25.5%) control patients. The differences between the overall survival curves were not significant. Progression rates at 12 and 24 months were higher for the placebo group (p = 0.088) with 2-year probabilities of progressing of 20.4% for Cop 1 and 29.5% for placebo. We found a significant difference at 24 months between placebo and Cop 1 at one but not the other center. Two-year progression rates for two secondary end points, unconfirmed progression, and progression of 0.5 EDSS units, (p = 0.03) are significant.
Cop 1 is a random polymer (molecular weight, 14,000 to 23,000) simulating myelin basic protein. It is synthesized by polymerizing L-alanine, L-glutamic acid, L-lysine, and L-tyrosine. It suppresses ...but does not induce experimental allergic encephalomyelitis, an animal model of multiple sclerosis. It is not toxic in animals. In a double-blind, randomized, placebo-controlled pilot trial, we studied 50 patients with the exacerbating-remitting form of multiple sclerosis, who self-injected either 20 mg of Cop 1 dissolved in 1 ml of saline or saline alone daily for two years. Six of 23 patients in the placebo group (26 percent) and 14 of 25 patients in the Cop 1 group (56 percent) had no exacerbations (P = 0.045). There were 62 exacerbations in the placebo group and 16 in the Cop 1 group, yielding two-year averages of 2.7 and 0.6 per patient, respectively. Among patients who were less disabled on entry (Kurtzke disability score, 0 to 2), there were 2.7 exacerbations in the placebo group and 0.3 in the Cop 1 group over two years. Among patients who were more affected (Kurtzke disability score, 3 to 6), there was an average of 2.7 exacerbations in the placebo group and 1.0 in the Cop 1 group. Over two years, less disabled patients taking Cop 1 improved an average of 0.5 Kurtzke units; those taking placebo worsened an average of 1.2 Kurtzke units. More disabled patients worsened by 0.3 (Cop 1 group) and 0.4 (placebo group) unit. Irritation at injection sites and rare, transient vasomotor responses were observed as side effects. These results suggest that Cop 1 may be beneficial in patients with the exacerbating-remitting form of multiple sclerosis, but we emphasize that the study is a preliminary one and our data require confirmation by a more extensive clinical trial.
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