15 research outputs found
Cobalt-Exchanged Mordenite onto a Cordierite Honeycomb for SCR-NO
Structured catalysts were prepared by deposition of cobalt-exchanged mordenite films on the walls of cordierite monolith channels either by wash coating or by hydrothermal synthesis. The aim of this work is to analyze different deposition techniques and their influence on the catalytic activity. The catalytic activity of the structured materials is compared with that of zeolite powder. The hydrothermal synthesis was performed in situ in a pressured autoclave reactor varying the reaction conditions (time, stirring degree). This technique consists in the crystallization of mordenite on the cordierite honeycombs employed as a substrate. In order to analyze the stirring effect, some of the samples were synthesized by stirring while others were treated in a stagnant medium. The influence of time on reaction was estimated by sampling at regular time intervals. Deposition by impregnation (wash coating) was also performed by immersing the monolith into a suspension (20-40 wt.%) with Co-exchanged mordenite. The wash coating was performed under different conditions (suspension concentration, incorporation of agglutinants, number of immersions) to obtain a zeolite coating active and selective as catalyst for nitric oxide selective reduction with hydrocarbons. The samples obtained by either method were characterized by scanning microscopy, TPR, XRD, and catalytic activity for the SCR of NOx with propane.Fil: Ercoli, M. A.. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata. Centro de InvestigaciĂłn y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de InvestigaciĂłn y Desarrollo en Ciencias Aplicadas; ArgentinaFil: Zamaro, Juan Manuel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y PetroquĂmica "Ing. JosĂ© Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y PetroquĂmica "Ing. JosĂ© Miguel Parera"; ArgentinaFil: Quincoces, Claudia Edith. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata. Centro de InvestigaciĂłn y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de InvestigaciĂłn y Desarrollo en Ciencias Aplicadas; ArgentinaFil: Miro, Eduardo Ernesto. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y PetroquĂmica "Ing. JosĂ© Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y PetroquĂmica "Ing. JosĂ© Miguel Parera"; ArgentinaFil: GĂłnzalez, MarĂa Gloria. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata. Centro de InvestigaciĂłn y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de InvestigaciĂłn y Desarrollo en Ciencias Aplicadas; Argentin
Triamcinolone solubilization by (2-hydroxypropyl)-β-cyclodextrin: a spectroscopic and computational approach
The molecular foundations of the use of hydroxypropyl-beta-cyclodextrin (HPβCD) as solubility promoter of triamcinolone acetonide (TrA), a corticosteroid with very low aqueous solubility, was investigated by a multidisciplinary spectroscopic and computational approach. Aqueous solutions of TrA and HPβCD were investigated by UV and NMR spectroscopies. The association constant was determined by phase solubility diagrams and by the Foster-Fyfe method whereas the nature of the drug/cyclodextrin aggregates was probed by using the NMR DOSY technique. ROE measurements in solution led to stereochemical information regarding the nature of inclusion processes. TrA/HPβCD powders were prepared and investigated by Raman spectroscopy supported by computational methods. A molecular interaction of the hydroxyacyl chain with cyclodextrin, not identified in solution, was detected. Raman imaging experiments confirmed the attainment of a molecularly homogeneous system when the TrA/HPβCD molar ratio was 1:7 whereas TrA crystallized for mixtures richer in TrA (1:3.5) forming domains with size in the range of 10–15 m. We demonstrate that the combined use of several spectroscopical techniques with specific responsivities allows a detailed depiction of drug/cyclodextrin interaction useful in the development of novel pharmaceutical formulation
Quality assessment of human mitochondrial DNA quantification : MITONAUTS, an international multicentre survey
Mitochondrial DNA quantification by qPCR is used in the context of many diseases and toxicity studies but comparison of results between laboratories is challenging. Through two multigroup distributions of DNA samples from human cell lines, the MITONAUTS group anonymously compared mtDNA/nDNA quantification across nine laboratories involved in HIV research worldwide. Eight of the nine sites showed significant correlation between them (mean raw data R(2)=0.664; log(10)-transformed data R(2)=0.844). Although mtDNA/nDNA values were well correlated between sites, the inter-site variability on the absolute measurements remained high with a mean (range) coefficient of variation of 71 (37-212) %. Some variability appeared cell line-specific, probably due to chromosomal alterations or pseudogenes affecting the quantification of certain genes, while within cell line variability was likely due to differences in calibration of the standard curves. The use of two mtDNA and two single copy nDNA genes with highly specific primers to quantify each genome would help address copy number variants. Our results indicate that sample shipment must be done frozen and that absolute mtDNA/nDNA ratio values cannot readily be compared between laboratories, especially if assessing cultured cell mtDNA content. However, within laboratory and relative mtDNA/nDNA comparisons between laboratories should be reliable
Limitation of life support techniques at admission to the intensive care unit : A multicenter prospective cohort study
To determine the frequency of limitations on life support techniques (LLSTs) on admission to intensive care units (ICU), factors associated, and 30-day survival in patients with LLST on ICU admission. This prospective observational study included all patients admitted to 39 ICUs in a 45-day period in 2011. We recorded hospitals' characteristics (availability of intermediate care units, usual availability of ICU beds, and financial model) and patients' characteristics (demographics, reason for admission, functional status, risk of death, and LLST on ICU admission (withholding/withdrawing; specific techniques affected)). The primary outcome was 30-day survival for patients with LLST on ICU admission. Statistical analysis included multilevel logistic regression models. We recruited 3042 patients (age 62.5 ± 16.1 years). Most ICUs (94.8%) admitted patients with LLST, but only 238 (7.8% [95% CI 7.0-8.8]) patients had LLST on ICU admission; this group had higher ICU mortality (44.5 vs. 9.4% in patients without LLST; p < 0.001). Multilevel logistic regression showed a contextual effect of the hospital in LLST on ICU admission (median OR = 2.30 [95% CI 1.59-2.96]) and identified the following patient-related variables as independent factors associated with LLST on ICU admission: age, reason for admission, risk of death, and functional status. In patients with LLST on ICU admission, 30-day survival was 38% (95% CI 31.7-44.5). Factors associated with survival were age, reason for admission, risk of death, and number of reasons for LLST on ICU admission. The frequency of ICU admission with LLST is low but probably increasing; nearly one third of these patients survive for ≥ 30 days
Pegylated interferon plus ribavirin in HIV-infected patients with recurrent hepatitis C after liver transplantation: A prospective cohort study (vol 62, pg 92, 2015)
Direct-acting antivirals are effective and safe in HCV/HIV-coinfected liver transplant recipients who experience recurrence of hepatitis C: A prospective nationwide cohort study
Direct-acting antivirals have proved to be highly efficacious and safe in monoinfected liver transplant (LT) recipients who experience recurrence of hepatitis C virus (HCV) infection. However, there is a lack of data on effectiveness and tolerability of these regimens in HCV/HIV-coinfected patients who experience recurrence of HCV infection after LT. In this prospective, multicenter cohort study, the outcomes of 47 HCV/HIV-coinfected LT patients who received DAA therapy (with or without ribavirin [RBV]) were compared with those of a matched cohort of 148 HCV-monoinfected LT recipients who received similar treatment. Baseline characteristics were similar in both groups. HCV/HIV-coinfected patients had a median (IQR) CD4 T-cell count of 366 (256-467) cells/µL. HIV-RNA wa
Direct-acting antivirals are effective and safe in HCV/HIV-coinfected liver transplant recipients who experience recurrence of hepatitis C: A prospective nationwide cohort study.
Direct-acting antivirals have proved to be highly efficacious and safe in monoinfected liver transplant (LT) recipients who experience recurrence of hepatitis C virus (HCV) infection. However, there is a lack of data on effectiveness and tolerability of these regimens in HCV/HIV-coinfected patients who experience recurrence of HCV infection after LT. In this prospective, multicenter cohort study, the outcomes of 47 HCV/HIV-coinfected LT patients who received DAA therapy (with or without ribavirin [RBV]) were compared with those of a matched cohort of 148 HCV-monoinfected LT recipients who received similar treatment. Baseline characteristics were similar in both groups. HCV/HIV-coinfected patients had a median (IQR) CD4 T-cell count of 366 (256-467) cells/µL. HIV-RNA wa
Limitation of life support techniques at admission to the intensive care unit: a multicenter prospective cohort study
Abstract Purpose To determine the frequency of limitations on life support techniques (LLSTs) on admission to intensive care units (ICU), factors associated, and 30-day survival in patients with LLST on ICU admission. Methods This prospective observational study included all patients admitted to 39 ICUs in a 45-day period in 2011. We recorded hospitals’ characteristics (availability of intermediate care units, usual availability of ICU beds, and financial model) and patients’ characteristics (demographics, reason for admission, functional status, risk of death, and LLST on ICU admission (withholding/withdrawing; specific techniques affected)). The primary outcome was 30-day survival for patients with LLST on ICU admission. Statistical analysis included multilevel logistic regression models. Results We recruited 3042 patients (age 62.5 ± 16.1 years). Most ICUs (94.8%) admitted patients with LLST, but only 238 (7.8% [95% CI 7.0–8.8]) patients had LLST on ICU admission; this group had higher ICU mortality (44.5 vs. 9.4% in patients without LLST; p < 0.001). Multilevel logistic regression showed a contextual effect of the hospital in LLST on ICU admission (median OR = 2.30 [95% CI 1.59–2.96]) and identified the following patient-related variables as independent factors associated with LLST on ICU admission: age, reason for admission, risk of death, and functional status. In patients with LLST on ICU admission, 30-day survival was 38% (95% CI 31.7–44.5). Factors associated with survival were age, reason for admission, risk of death, and number of reasons for LLST on ICU admission. Conclusions The frequency of ICU admission with LLST is low but probably increasing; nearly one third of these patients survive for ≥ 30 days
Limitation of life support techniques at admission to the intensive care unit: a multicenter prospective cohort study
Purpose: To determine the frequency of limitations on life support techniques (LLSTs) on admission to intensive
care units (ICU), factors associated, and 30-day survival in patients with LLST on ICU admission.
Methods: This prospective observational study included all patients admitted to 39 ICUs in a 45-day period in 2011.
We recorded hospitals’ characteristics (availability of intermediate care units, usual availability of ICU beds, and financial
model) and patients’ characteristics (demographics, reason for admission, functional status, risk of death, and LLST on
ICU admission (withholding/withdrawing; specific techniques affected)). The primary outcome was 30-day survival for
patients with LLST on ICU admission. Statistical analysis included multilevel logistic regression models.
Results: We recruited 3042 patients (age 62.5 ± 16.1 years). Most ICUs (94.8%) admitted patients with LLST, but only
238 (7.8% [95% CI 7.0–8.8]) patients had LLST on ICU admission; this group had higher ICU mortality (44.5 vs. 9.4% in
patients without LLST; p < 0.001). Multilevel logistic regression showed a contextual effect of the hospital in LLST on ICU
admission (median OR = 2.30 [95% CI 1.59–2.96]) and identified the following patient-related variables as independent
factors associated with LLST on ICU admission: age, reason for admission, risk of death, and functional status. In patients
with LLST on ICU admission, 30-day survival was 38% (95% CI 31.7–44.5). Factors associated with survival were age, reason
for admission, risk of death, and number of reasons for LLST on ICU admission.
Conclusions: The frequency of ICU admission with LLST is low but probably increasing; nearly one third of these patients
survive for ≥ 30 days