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1.
Adv Colloid Interface Sci ; 321: 103034, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37918301

ABSTRACT

The theory developed in 1922 by Wolfgang Ostwald and Ramón de Izaguirre for adsorption from solution is revisited one hundred years later, with a main focus on its impact and repercussions. A concise historical account is initiated with an examination of the circumstances under which that work was generated. After providing some biographic data about the authors' backgrounds at the time they developed it, a concise description of the so-called Ostwald-de Izaguirre theory is presented. This is followed by an assessment of its impact as a whole in the first decades after it was produced. Starting from about 1960, interest was focused on two separate outcomes from the theory: (i) the first classification of adsorption isotherms ever proposed, and (ii) an equation (Ostwald-de Izaguirre equation) that describes adsorption by solids of binary mixtures of miscible liquids and allows separating the contributions from both components of the solution. Although still in occasional use today, the isotherm classification made by Ostwald and de Izaguirre is of almost exclusively historical interest, having been displaced by Giles' classification. Unlike this, the Ostwald-de Izaguirre equation is still used and, since it derives from a simple mass balance, there is general agreement that no assumptions were made that limit its use. Thus, it seems that there is nothing to prevent the applicability of this equation in the future.

2.
ACS Appl Mater Interfaces ; 13(46): 54860-54873, 2021 Nov 24.
Article in English | MEDLINE | ID: mdl-34752069

ABSTRACT

Phosphate-functionalized carbon-based nanomaterials have attracted significant attention in recent years owing to their outstanding behavior in electrochemical energy-storage devices. In this work, we report a simple approach to obtain phosphate-functionalized graphene (PFG) via anodic exfoliation of graphite at room temperature with a high yield. The graphene nanosheets were obtained via anodic exfoliation of graphite foil using aqueous solutions of H3PO4 or Na3PO4 in the dual role of phosphate sources and electrolytes, and the underlying exfoliation/functionalization mechanisms are proposed. The effect of electrolyte concentration was studied, as low concentrations do not lead to a favorable graphite exfoliation and high concentrations produce fast graphite expansion but poor layer-by-layer delamination. The optimal concentrations are 0.25 M H3PO4 and 0.05 M Na3PO4, which also exhibited the highest phosphorus contents of 2.2 and 1.4 at. %, respectively. Furthermore, when PFG-acid at 0.25 M and PFG-salt at 0.05 M were tested as an electrode material for capacitive energy storage in a three-electrode cell, they achieved a competitive performance of ∼375 F/g (540 F/cm3) and 356 F/g (500 F/cm3), respectively. Finally, devices made up of symmetric electrode cells obtained using PFG-acid at 0.25 M possess energy and power densities up to 17.6 Wh·kg-1 (25.3 Wh·L-1) and 10,200 W/kg; meanwhile, PFG-salt at 0.05 M achieved values of 14.9 Wh·kg-1 (21.3 Wh·L-1) and 9400 W/kg, with 98 and 99% of capacitance retention after 10,000 cycles, respectively. The methodology proposed here also promotes a circular-synthesis process to successfully achieve a more sustainable and greener energy-storage device.

3.
ACS Appl Mater Interfaces ; 12(1): 494-506, 2020 Jan 08.
Article in English | MEDLINE | ID: mdl-31825208

ABSTRACT

Integrated approaches that expedite the production and processing of graphene into useful structures and devices, particularly through simple and environmentally friendly strategies, are highly desirable in the efforts to implement this two-dimensional material in state-of-the-art electrochemical energy storage technologies. Here, we introduce natural nucleotides (e.g., adenosine monophosphate) as bifunctional agents for the electrochemical exfoliation and dispersion of graphene nanosheets in water. Acting both as exfoliating electrolytes and colloidal stabilizers, these biomolecules facilitated access to aqueous graphene bio-inks that could be readily processed into aerogels and inkjet-printed interdigitated patterns. Na-O2 batteries assembled with the graphene-derived aerogels as the cathode and a glyme-based electrolyte exhibited a full discharge capacity of ∼3.8 mAh cm-2 at a current density of 0.2 mA cm-2. Moreover, shallow cycling experiments (0.5 mAh cm-2) boasted a capacity retention of 94% after 50 cycles, which outperformed the cycle life of prior graphene-based cathodes for this type of battery. The positive effect of the nucleotide-adsorbed nanosheets on the battery performance is discussed and related to the presence of the phosphate group in these biomolecules. Microsupercapacitors made from the interdigitated graphene patterns as the electrodes also displayed a competitive performance, affording areal and volumetric energy densities of 0.03 µWh cm-2 and 1.2 mWh cm-3 at power densities of 0.003 mW cm-2 and 0.1 W cm-3, respectively. Taken together, by offering a green and straightforward route to different types of functional graphene-based materials, the present results are expected to ease the development of novel energy storage technologies that exploit the attractions of graphene.

4.
ACS Appl Mater Interfaces ; 11(40): 36991-37003, 2019 Oct 09.
Article in English | MEDLINE | ID: mdl-31516002

ABSTRACT

The production of MoS2 nanosheets by electrochemical exfoliation routes holds great promise as a means to access this two-dimensional material in large quantities for different practical applications. However, the use of electrolytes based on synthetic organic salts and solvents, as well as issues related to the unwanted oxidation and/or phase transformation of the exfoliated nanosheets, constitute significant obstacles that hinder the industrial adoption of the electrochemical approach. Here, we introduce a safe and sustainable method for the cathodic delamination of MoS2 that makes use of aqueous solutions of very simple and widely available salts, mainly KCl, as the electrolyte. Combined with an appropriate biomolecule-based solvent transfer protocol, such an electrolytic exfoliation route is shown to afford colloidally dispersed, oxide-free, and phase-preserved MoS2 nanosheets of high structural quality in considerable yields. The mechanisms behind the efficient aqueous delamination of the bulk MoS2 cathode are also discussed and rationalized on the basis of the penetration of hydrated cations from the electrolyte between its layers and the immediate reduction of the accompanying water molecules. An asymmetric supercapacitor assembled with a cathodic MoS2 nanosheet-single walled carbon nanotube hybrid as the positive electrode and activated carbon as the negative electrode delivered energy densities (e.g., 26 W h kg-1 at 750 W kg-1 in 6 M KOH) that were competitive with those of other MoS2-based asymmetric devices. When used as a catalyst for the reduction of nitroarenes, the present cathodically exfoliated nanosheets exhibited one of the highest activities reported so far with MoS2 nanostructures, the origin of which is accounted for as well. Overall, by facilitating access to this two-dimensional material through a particularly simple, efficient, and cost-effective technique, these results should expedite the practical implementation of MoS2 nanosheets in energy storage, catalysis, and beyond.

5.
Case Rep Emerg Med ; 2018: 4328704, 2018.
Article in English | MEDLINE | ID: mdl-30729046

ABSTRACT

Pneumothorax is the entry of air into the virtual space between the visceral and the parietal pleurae, which can occur spontaneously or to a greater extent in a traumatic way. In daily clinical practice it is frequent to find injuries that generate traumatic pneumothorax that is ipsilateral to the lesion. However, there are case reports of contralateral pneumothorax that occurred in procedures such as insertion of pacemakers, or in cases of pneumonectomy. The following is the case report of a 37-year-old man who was admitted with a sharp wound to the right paravertebral region who developed a left haemopneumothorax due to a tangential course of the injuring agent. Adequate clinical judgment was followed, and several imaging studies were carried out, leading to the diagnosis of traumatic pneumothorax that was contralateral to the described injury.

6.
ACS Appl Mater Interfaces ; 9(3): 2835-2845, 2017 Jan 25.
Article in English | MEDLINE | ID: mdl-28029778

ABSTRACT

The exfoliation and colloidal stabilization of layered transition metal dichalcogenides (TMDs) in an aqueous medium using functional biomolecules as dispersing agents have a number of potential benefits toward the production and practical use of the corresponding two-dimensional materials, but such a strategy has so far remained underexplored. Here, we report that DNA and RNA nucleotides are highly efficient dispersants in the preparation of stable aqueous suspensions of MoS2 and other TMD nanosheets at significant concentrations (up to 5-10 mg mL-1). Unlike the case of common surfactants, for which adsorption on 2D materials is generally based on weak dispersive forces, the exceptional colloidal stability of the TMD flakes was shown to rely on the presence of relatively strong, specific interactions of Lewis acid-base type between the DNA/RNA nucleotide molecules and the flakes. Moreover, the nucleotide-stabilized MoS2 nanosheets were shown to be efficient catalysts in the reduction of nitroarenes (4-nitrophenol and 4-nitroaniline), thus constituting an attractive alternative to the use of expensive heterogeneous catalysts based on noble metals, and exhibited an electrocatalytic activity toward the hydrogen evolution reaction that was not impaired by the possible presence of nucleotide molecules adsorbed on their active sites. The biocompatibility of these materials was also demonstrated on the basis of cell proliferation and viability assays. Overall, the present work opens new vistas on the colloidal stabilization of 2D materials based on specific interactions that could be useful toward different practical applications.


Subject(s)
Transition Elements/chemistry , DNA , Nucleotides , RNA , Water
7.
ACS Appl Mater Interfaces ; 8(41): 27974-27986, 2016 Oct 19.
Article in English | MEDLINE | ID: mdl-27704765

ABSTRACT

Chemically exfoliated MoS2 (ce-MoS2) has emerged in recent years as an attractive two-dimensional material for use in relevant technological applications, but fully exploiting its potential and versatility will most probably require the deployment of appropriate chemical modification strategies. Here, we demonstrate that extensive covalent functionalization of ce-MoS2 nanosheets with acetic acid groups (∼0.4 groups grafted per MoS2 unit) based on the organoiodide chemistry brings a number of benefits in terms of their processability and functionality. Specifically, the acetic acid-functionalized nanosheets were furnished with long-term (>6 months) colloidal stability in aqueous medium at relatively high concentrations, exhibited a markedly improved temporal retention of catalytic activity toward the reduction of nitroarenes, and could be more effectively coupled with silver nanoparticles to form hybrid nanostructures. Furthermore, in vitro cell proliferation tests carried out with murine fibroblasts suggested that the chemical derivatization had a positive effect on the biocompatibility of ce-MoS2. A hydrothermal annealing procedure was also implemented to promote the structural conversion of the functionalized nanosheets from the 1T phase that was induced during the chemical exfoliation step to the original 2H phase of the starting bulk material, while retaining at the same time the aqueous colloidal stability afforded by the presence of the acetic acid groups. Overall, by highlighting the benefits of this type of chemical derivatization, the present work should contribute to strengthen the position of ce-MoS2 as a two-dimensional material of significant practical utility.

8.
Am J Cardiol ; 115(9): 1174-8, 2015 May 01.
Article in English | MEDLINE | ID: mdl-25759106

ABSTRACT

To investigate the role of hydration to prevent contrast-induced nephropathy (CIN) in patients with ST-segment elevation myocardial infarction (STEMI) who underwent primary percutaneous coronary intervention (PPCI), we prospectively included 408 consecutive patients who were randomly assigned to receive either hydration with isotonic saline (1 ml/kg/h since the beginning of the procedure and for 24 hours after it: NS+ group) or not (NS- group). All patients received an iso-osmolar nonionic contrast medium. The primary end point was the development of CIN: ≥25% or ≥0.5 mg/dl increase in serum creatinine within 3 days after the procedure. CIN was observed in 14% of patients: 21% in the NS- group and 11% in the NS+ group (p=0.016). CIN was significantly associated with death (15.2% vs 2.8%; p<0.0001) and need for dialysis (13.4% vs 0%; p<0.0001). In multivariate analysis, the only predictors of CIN were hydration (OR=0.29 [0.14 to 0.66]; p=0.003) and the hemoglobin before the procedure (OR=0.69 [0.59 to 0.88]; p<0.0001). In conclusion, intravenous saline hydration during PPCI reduced the risk of CIN to 48%. Patients with CIN had increased mortality and need for dialysis. Given the higher incidence of CIN in emergent procedures, and its morbidity and mortality, preventive hydration should be mandatory in them unless contraindicated.


Subject(s)
Contrast Media/adverse effects , Fluid Therapy , Kidney Diseases/chemically induced , Kidney Diseases/prevention & control , Myocardial Infarction/surgery , Percutaneous Coronary Intervention , Aged , Creatinine/blood , Female , Humans , Intraoperative Care , Isotonic Solutions , Kidney Diseases/blood , Kidney Diseases/mortality , Male , Middle Aged , Prospective Studies , Sodium Chloride/therapeutic use , Triiodobenzoic Acids/adverse effects
9.
Nanoscale ; 7(6): 2374-90, 2015 Feb 14.
Article in English | MEDLINE | ID: mdl-25563664

ABSTRACT

High temperature annealing is the only method known to date that allows the complete repair of a defective lattice of graphenes derived from graphite oxide, but most of the relevant aspects of such restoration processes are poorly understood. Here, we investigate both experimentally (scanning probe microscopy) and theoretically (molecular dynamics simulations) the thermal evolution of individual graphene oxide sheets, which is rationalized on the basis of the generation and the dynamics of atomic vacancies in the carbon lattice. For unreduced and mildly reduced graphene oxide sheets, the amount of generated vacancies was so large that they disintegrated at 1773-2073 K. By contrast, highly reduced sheets survived annealing and their structure could be completely restored at 2073 K. For the latter, a minor atomic-sized defect with six-fold symmetry was observed and ascribed to a stable cluster of nitrogen dopants. The thermal behavior of the sheets was significantly altered when they were supported on a vacancy-decorated graphite substrate, as well as for the overlapped/stacked sheets. In these cases, a net transfer of carbon atoms between neighboring sheets via atomic vacancies takes place, affording an additional healing process. Direct evidence of sheet coalescence with the step edge of the graphite substrate was also gathered from experiments and theory.

10.
ACS Appl Mater Interfaces ; 6(23): 21702-10, 2014 Dec 10.
Article in English | MEDLINE | ID: mdl-25405770

ABSTRACT

Chemically exfoliated MoS2 (ce-MoS2) nanosheets that incorporate a large fraction of metallic 1T phase have been recently shown to possess a high electrocatalytic activity in the hydrogen evolution reaction, but the potential of this two-dimensional material as a catalyst has otherwise remained mostly uncharted. Here, we demonstrate that ce-MoS2 nanosheets are efficient catalysts for a number of model reduction reactions (namely, those of 4-nitrophenol, 4-nitroaniline, methyl orange, and [Fe(CN)6](3-)) carried out in aqueous medium using NaBH4 as a reductant. The performance of the nanosheets in these reactions is found to be comparable to that of many noble metal-based catalysts. The possible reaction pathways involving ce-MoS2 as a catalyst are also discussed and investigated. Overall, the present results expand the scope of this two-dimensional material as a competitive, inexpensive, and earth-abundant catalyst.

11.
ACS Appl Mater Interfaces ; 6(23): 21237-47, 2014 Dec 10.
Article in English | MEDLINE | ID: mdl-25347795

ABSTRACT

Doped porous carbons exhibiting highly developed porosity and rich surface chemistry have been prepared and subsequently applied to clarify the influence of both factors on carbon dioxide capture. Nanocasting was selected as synthetic route, in which a polyaramide precursor (3-aminobenzoic acid) was thermally polymerized inside the porosity of an SBA-15 template in the presence of different H3PO4 concentrations. The surface chemistry and the porous texture of the carbons could be easily modulated by varying the H3PO4 concentration and carbonization temperature. Porous texture was found to be the determinant factor on carbon dioxide adsorption at 0 °C, while surface chemistry played an important role at higher adsorption temperatures. We proved that nitrogen functionalities acted as basic sites and oxygen and phosphorus groups as acidic ones toward adsorption of CO2 molecules. Among the nitrogen functional groups, pyrrolic groups exhibited the highest influence, while the positive effect of pyridinic and quaternary functionalities was smaller. Finally, some of these N-doped carbons exhibit CO2 heats of adsorption higher than 42 kJ/mol, which make them excellent candidates for CO2 capture.

12.
Resuscitation ; 85(9): 1245-50, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24929199

ABSTRACT

BACKGROUND: Identification of acute coronary lesions amenable to urgent intervention in survivors of out-of-hospital cardiac arrest is crucial. We aimed to compare the clinical and electrocardiographic characteristics to urgent coronary findings, and to analyze in-hospital prognosis of these patients. METHODS: From January 2005 to December 2012 we retrospectively identified consecutive patients resuscitated from out-of-hospital cardiac arrest, and analyzed the clinical characteristics, post-resuscitation electrocardiogram and coronary angiogram of those who underwent emergent angiography. Mortality and neurologic status at discharge were also assessed. RESULTS: Patients with ST-elevation more frequently had obstructive coronary artery disease (89% vs. 51%, p<0.001) or acute coronary occlusions (83% vs. 8%, p<0.001) than patients without ST-elevation. Independent predictors of an acute coronary occlusion were chest pain before arrest (OR 0.16, 95% CI 0.04-0.7, p=0.01), a shockable initial rhythm (OR 0.16, 95% CI 0.03-0.9, p=0.03), and ST-elevation on the post-resuscitation electrocardiogram (OR 0.02, 95% CI 0.004-0.13, p<0.001). Survival with favorable neurologic recovery at discharge was 59%. Independent predictors of mortality or unfavorable neurological outcome at discharge were absence of basic life support (OR 0.2, 95% CI 0.06-0.9, p=0.04), prolonged resuscitation time (OR 0.9, 95% CI 0.8-0.9, p=0.01), and necessity of vasopressors (OR 14.8, 95% CI 3.3-65.4, p=0.001). CONCLUSIONS: Most patients with ST-elevation on the post-resuscitation electrocardiogram had an acute coronary occlusion, as opposed to patients without ST-elevation. Absence of basic life support, prolonged resuscitation time and use of vasopressors were independent predictors of worse in-hospital outcome.


Subject(s)
Cardiopulmonary Resuscitation , Electrocardiography , Out-of-Hospital Cardiac Arrest/physiopathology , Out-of-Hospital Cardiac Arrest/therapy , Coronary Angiography , Female , Hospitalization , Humans , Male , Middle Aged , Out-of-Hospital Cardiac Arrest/diagnostic imaging , Patient Discharge , Prognosis , Retrospective Studies , Survivors
13.
Cardiovasc Revasc Med ; 14(6): 356-8, 2013.
Article in English | MEDLINE | ID: mdl-24267597

ABSTRACT

Primary percutaneous intervention of saphenous vein grafts is associated with a high risk of distal embolization and no reflow. We report a case of acute myocardial infarction with a large intragraft thrombus, successfully treated with a technique combining thrombectomy with a 6 Fr guiding catheter and distal protection with the FilterWire EZ.


Subject(s)
Cardiac Catheterization/methods , Graft Occlusion, Vascular/surgery , Myocardial Infarction/surgery , Percutaneous Coronary Intervention , Saphenous Vein/surgery , Stents , Thrombectomy , Angioplasty, Balloon, Coronary/methods , Graft Occlusion, Vascular/diagnosis , Humans , Male , Middle Aged , Myocardial Infarction/diagnosis , Percutaneous Coronary Intervention/methods , Saphenous Vein/transplantation , Thrombectomy/methods , Treatment Outcome
14.
ChemSusChem ; 6(8): 1406-13, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23843334

ABSTRACT

High-performance carbon materials for energy storage applications have been obtained by using poly(m-phenylene isophthalamide), PMIA, as a precursor through the chemical activation of the carbonized aramid fiber by using KOH. The yield of the process of activation was remarkably high (25-40 wt%), resulting in activated carbon fibers (ACFs) with ultrahigh surface areas, over 3000 m(2) g(-1) , and pore volumes exceeding 1.50 cm(3) g(-1) , keeping intact the fibrous morphology. The porous structure and the surface chemical properties could easily be controlled through the conditions of activation. The PMIA-derived ACFs were tested in two types of energy storage applications. At -196 °C and 1 bar, H2 uptake values of approximately 3 t% were obtained, which, in combination with the textural properties, rendered it a good candidate for H2 adsorption at high pressure and temperature. The performance of the ACFs as electrodes for electrochemical supercapacitors was also investigated. Specific capacitance values between 297 and 531 g(-1) at 50 mA g(-1) were obtained in aqueous electrolyte (1 H2 SO4 ), showing different behaviors depending on the surface chemical properties.


Subject(s)
Amides/chemistry , Carbon/chemistry , Energy-Generating Resources , Phthalic Acids/chemistry , Carbon Fiber , Chemical Phenomena , Electrochemistry , Hydrogen/chemistry , Potassium Chloride/chemistry , Surface Properties
15.
Cardiovasc Revasc Med ; 13(6): 362-4, 2012.
Article in English | MEDLINE | ID: mdl-23084325

ABSTRACT

Spontaneous coronary artery dissection (SCAD) is a rare cause of acute coronary syndrome. Knowledge of this condition is scarce and, at present, no consensus exists with regards to the aetiology, prognosis, and treatment. Among patients with SCAD, cases involving the left main (LM) and the left anterior descending (LAD) and circumflex (Cx) arteries bifurcation are even more exceptional. Furthermore, the treatment of asymptomatic patients with involvement of these major vessels poses a major challenge for the cardiologists and cardiac surgeons. We report a case of complicated spontaneous left main coronary artery dissection in which we question what is the best initial treatment in these asymptomatic patients: conservative or early aggressive.


Subject(s)
Acute Coronary Syndrome/surgery , Aortic Dissection/surgery , Coronary Angiography , Coronary Vessels/diagnostic imaging , Acute Coronary Syndrome/diagnosis , Acute Coronary Syndrome/diagnostic imaging , Adult , Aortic Dissection/diagnosis , Aortic Dissection/diagnostic imaging , Female , Humans , Prognosis
16.
Rev. esp. cardiol. (Ed. impr.) ; 64(11): 1052-1055, nov. 2011. tab, ilus
Article in Spanish | IBECS | ID: ibc-91160

ABSTRACT

Muchos pacientes con estenosis aórtica severa, por diferentes razones, nunca llegan a beneficiarse del tratamiento quirúrgico. Existe un grupo de pacientes en los que a sus comorbilidades se añade otro problema: ser portadores de prótesis mitral mecánica. En estos pacientes, la implantación transcatéter de prótesis valvular aórtica es una opción. Se han publicado pocos casos de este procedimiento en portadores de prótesis mecánica mitral, muchos realizados por vía transapical. Presentamos 3 casos de pacientes con estenosis aórtica severa portadores de prótesis mitral mecánica y alto riesgo para cirugía en los que se implantaron, por vía transfemoral, prótesis valvular aórtica de Edwards con éxito y sin complicaciones (AU)


Many patients with severe aortic stenosis never undergo surgical treatment for various reasons. Apart from the standard risks, some patients face an additional problem: their carrying of a mechanical mitral valve. In these patients, transcatheter aortic valve implantation is a therapeutic option. The literature contains only few reports of this procedure being performed (usually transapically) in such patients. This paper reports the cases of 3 patients with severe aortic stenosis, all carrying a mechanical mitral valve and at high surgical risk, all of whom were implanted by transcatheter aortic valve implantation with an Edwards aortic valve prosthesis. All procedures were successful with no complications encountered (AU)


Subject(s)
Humans , Female , Middle Aged , Aged, 80 and over , Heart Valve Prosthesis , /methods , Mitral Valve/surgery , Mitral Valve Stenosis/surgery , Mitral Valve Stenosis , Retrospective Studies , Echocardiography , /methods
17.
J Colloid Interface Sci ; 361(1): 307-15, 2011 Sep 01.
Article in English | MEDLINE | ID: mdl-21669440

ABSTRACT

Activated carbon fibers (ACFs) were prepared by chemical activation of poly(p-phenylene terephthalamide (PPTA) with phosphoric acid, with a particular focus on the effects of impregnation ratio and carbonization temperature on both surface chemistry and porous texture. Thermogravimetric studies of the pyrolysis of PPTA impregnated with different amounts of phosphoric acid indicated that this reagent has a strong influence on the thermal degradation of the polymer, lowering the decomposition temperature and increasing the carbon yield. As concerns surface chemistry, TPD and chemical analysis results indicated that the addition of phosphoric acid increases the concentration of oxygenated surface groups, with a maximum at an impregnation ratio of 100 wt.%. The resulting materials present uncommon properties, namely a large amount of oxygen- and phosphorus-containing surface groups and a high nitrogen content. Porosity development following H(3)PO(4) activation was very significant, with values close to 1700 m(2)/g and 0.80 cm(3)/g being reached for the BET surface area and total pore volume, respectively. The pore size distributions remained confined to the micropore and narrow mesopore (<10 nm) range.

18.
Rev Esp Cardiol ; 64(11): 1052-5, 2011 Nov.
Article in Spanish | MEDLINE | ID: mdl-21676522

ABSTRACT

Many patients with severe aortic stenosis never undergo surgical treatment for various reasons. Apart from the standard risks, some patients face an additional problem: their carrying of a mechanical mitral valve. In these patients, transcatheter aortic valve implantation is a therapeutic option. The literature contains only few reports of this procedure being performed (usually transapically) in such patients. This paper reports the cases of 3 patients with severe aortic stenosis, all carrying a mechanical mitral valve and at high surgical risk, all of whom were implanted by transcatheter aortic valve implantation with an Edwards aortic valve prosthesis. All procedures were successful with no complications encountered.


Subject(s)
Aortic Valve Insufficiency/surgery , Aortic Valve/surgery , Heart Valve Prosthesis Implantation/methods , Heart Valve Prosthesis , Mitral Valve/physiology , Aged , Aged, 80 and over , Aortic Valve Stenosis , Atrial Fibrillation/complications , Diabetes Mellitus, Type 2/complications , Echocardiography, Transesophageal , Female , Humans , Middle Aged , Minimally Invasive Surgical Procedures , Retrospective Studies , Tomography, X-Ray Computed
19.
Acta Cardiol ; 65(4): 387-94, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20821930

ABSTRACT

OBJECTIVE: Mild reductions in iodine concentration could reduce acute side effects after intraarterial contrast media administration without affecting the quality of coronary artery images. This study was designed to show the equivalence in terms of image quality of two nonionic low-osmolar monomers, iobitridol 350 and iopamidol 370, and to compare their clinical safety in coronary angiography and ventriculography. METHODS AND RESULTS: In this multicentre, double-blind clinical trial, 98 adult patients were randomized to receive either iobitridol 350 or iopamidol 370. The image quality (primary evaluation criterion) of the whole examination was assessed using a 5-point scale (poor, fair, moderate, good, excellent). Secondary endpoints were the image quality per territory, diagnostic efficacy, practical comfort (5-point scale: impossible to evaluate, not practical, moderately practical, practical, very practical to use) and clinical safety (adverse events and vital signs). The proportions of examinations presenting with good or excellent global image quality was similar with both contrast media: 87.8% with iobitridol 350 vs. 89.8% with iopamidol 370. Similar results were observed when considering the image quality specifically for each major coronary artery and left ventricle. No difference between groups was found with respect to other secondary criteria. Adverse events occurred in 7 patients with iobitridol 350 (14.3%) and in 10 patients with iopamidol 370 (20.4%). CONCLUSIONS: This study showed that, with regard to image quality and diagnostic efficacy and using a lower iodine concentration, iobitridol 350 was comparable to iopamidol 370 in adult patients requiring coronary angiography and ventriculography for diagnostic indications.


Subject(s)
Contrast Media/administration & dosage , Coronary Angiography , Heart Ventricles/diagnostic imaging , Iohexol/analogs & derivatives , Iopamidol/administration & dosage , Contrast Media/adverse effects , Double-Blind Method , Female , Humans , Injections, Intra-Arterial , Iohexol/administration & dosage , Iohexol/adverse effects , Iopamidol/adverse effects , Male , Middle Aged , Spain
20.
Rev Esp Cardiol ; 62(12): 1373-80, 2009 Dec.
Article in English | MEDLINE | ID: mdl-20038403

ABSTRACT

INTRODUCTION AND OBJECTIVES: This study was designed to compare differences in the incidence of contrast-induced nephropathy (CIN) and changes in serum creatinine (SCr) level following iso-osmolar iodixanol or low-osmolar ioversol administration in diabetic patients undergoing coronary angiography, with or without percutaneous coronary intervention (PCI). A number of studies have indicated that iodixanol reduces the risk of CIN in patients with renal impairment, with or without diabetes. Diabetic patients may have some degree of renal dysfunction despite having a normal SCr level. METHODS: The study included 250 consecutive diabetic patients undergoing coronary angiography with or without PCI. Those enrolled during the first 7 months of the study received ioversol and those enrolled during the following 11 months received iodixanol. The primary study endpoint was the incidence of CIN. Secondary objectives were to identify independent predictors of CIN and to determine the mean increase in SCr 72 hours after contrast injection. RESULTS: The overall incidence of CIN was 5.6%. The incidence of CIN was significantly lower with iodixanol than with ioversol (2.5% vs. 8.3%, respectively; odds ratio [OR]=0.255; 95% confidence interval [CI], 0.068-0.952; P=.047). A low estimated glomerular filtration rate (60.8+/-29 mL/min per 1.73 m2 in those with CIN vs. 75.3+/-25 mL/min per 1.73 m2 in those without; OR=0.975; 95% CI, 0.952-0.997; P=.03) and ioversol use were independent predictors of CIN. CONCLUSIONS: In diabetic patients undergoing diagnostic coronary angiography with or without PCI, the iso-osmolar contrast medium iodixanol was associated with a lower incidence of CIN than low-osmolar ioversol.


Subject(s)
Angioplasty, Balloon, Coronary , Contrast Media , Coronary Angiography , Kidney Diseases/chemically induced , Kidney Diseases/prevention & control , Triiodobenzoic Acids , Aged , Coronary Disease/complications , Coronary Disease/diagnosis , Coronary Disease/therapy , Creatinine/blood , Diabetic Angiopathies/diagnosis , Diabetic Angiopathies/therapy , Female , Humans , Kidney Diseases/blood , Kidney Diseases/epidemiology , Male , Prospective Studies
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