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M Gracia

Publications and source records attributed to M Gracia.

15 recordsLinked to original sources
PubMed2006

Relevance in the Fischer-Tropsch synthesis of the formation of Fe-O-Ce interactions on iron-cerium mixed oxide systems.

A series of Fe-Ce mixed oxides (95 atom % Fe-5 atom % Ce) has been prepared by different methods: coprecipitation, impregnation, and physical mixture of Ce and Fe oxides. These solids have been tested in the Fischer-Tropsch synthesis. The characterization of the catalytic precursors was carried out by X-ray diffraction (XRD), Raman, Mössbauer, and X-ray photoelectron (XPS) spectroscopic techniques. When the preparation method ensures a microscopic contact between Fe and Ce cations in the solid, several types of Fe-Ce interactions are present in the calcined solids. The interactions take the shape of Fe-O-Ce bridges that can exist either in the hematite-like solid solution or in the interphase between the Fe oxide covered by microcrystals of Ce oxide. In the case of the hematite-like solid solution, Ce(IV) cations are dissolved in the alpha-Fe2O3 network. The promotion by Ce of the catalytic properties observed in the final catalysts can be directly related with the detection of these Fe-O-Ce bridges in the calcined solids. The Ce promotion results in a larger yield to hydrocarbons, a higher production of olefins, and a higher selectivity to medium and large chain hydrocarbons (larger than six carbon atoms). It is proposed that the Ce promotion is due to the presence of Fe0-Ce(III) ensembles in the final catalysts arising from the initial Fe-O-Ce bridges developed in the parent calcined samples.

Journal Article↗
PubMed2005

Nanoscale investigation of the structural and chemical changes induced by oxidation on carbon black surfaces: a scanning probe microscopy approach.

Scanning tunneling microscopy (STM) and noncontact tapping mode atomic force microscopy (AFM) have been employed to study on a local scale the structural and, for the first time, the chemical changes of carbon black (CB) particles following plasma oxidation. STM imaging of the pristine, untreated particles revealed a relatively ordered structure of tiny crystallites with a few amorphous regions. After plasma treatment, the crystallites were no longer observed and the CB particle surface exhibited a noticeable and ubiquitous increase in atomic-scale disorder. Phase contrast images obtained with noncontact tapping mode AFM indicated that the untreated CB particles were essentially hydrophobic as a pristine basal surface of graphite, but with occasional hydrophilic patches. By contrast, their plasma-treated counterparts displayed enhanced hydrophilicity as a result of the introduction of oxygen onto the CB surface, the presence of which was evidenced by X-ray photoelectron spectroscopy, but most significantly, such enhancement was observed to be quite uniform at a local scale of individual particles. The possibility of investigating on a very local scale the chemical behavior of oxidized CB particles should be useful for the control and optimization of their dispersion properties in different systems.

Journal Article↗
PubMed2004

Antimicrobial susceptibility of Haemophilus influenzae, Haemophilus parainfluenzae and Moraxella catarrhalis isolated from adult patients with respiratory tract infections in four southern European countries. The ARISE project.

Over a 7-month period in 2000-2001, 1213 Haemophilus influenzae, 112 Haemophilus parainfluenzae and 142 Moraxella catarrhalis isolates were recovered from adult patients with respiratory tract infections. Patients were from four southern European countries (Spain, Italy, Portugal and Greece). The antimicrobial susceptibility of the isolates to 11 antibiotics was determined in a central laboratory. The most active drugs on the basis of MICs were levofloxacin, cefditoren, cefotaxime, cefpodoxime and amoxicillin/clavulanate. MICs > or = 2 mg/l for amoxicillin were found in 19.5, 28.6, and 75.4% of H. influenzae, H. parainfluenzae and M. catarrhalis isolates, respectively. Isolates of H. influenzae and H. parainfluenzae with reduced susceptibility or that were fully resistant to amoxicillin/clavulanate, cefuroxime and clarithromycin were detected (0.2-1.8%) as well as M. catarrhalis resistant to clarithromycin (0.7%). Regular surveys of resistance patterns for antimicrobial agents are necessary.

Adult↗
PubMed2004

Feeding regimen and enzyme supplementation to rye-based diets for broilers.

A trial was conducted to study the influence of feeding regimen [ad libitum, (AL) vs. feed restriction, (FR)] and supplementation of the diet with a combination of xylanase and beta-glucanase on physiological parameters and performance of broilers fed rye-based diets. There were 4 dietary treatments arranged factorially with 2 feeding regimens (0 vs. 30% FR from 4 to 14 d), 2 enzyme doses (0 vs. 500 ppm), and an additional corn control diet. Each treatment was replicated 9 times from 4 to 25 d (15 chicks caged together) and 6 times from 25 to 46 d. From 4 to 46 d of age, FR did not affect weight gain and improved feed conversion of broilers (P < 0.05). Also, FR reduced the incidence of leg disorders, digesta viscosity, and pasted vents (P < 0.01) and increased relative weight of gizzard (P < 0.001). Enzyme supplementation (ES) improved average daily gain and feed conversion at all ages (P < 0.01), and the beneficial effects were greater for AL than for FR birds (P < 0.10). Also, ES reduced digesta viscosity (P < 0.001), relative weights of gizzard (P < 0.05) and crop (P < 0.01), and jejunum length (P < 0.05). Compared with feeding corn, feeding rye AL with or without ES impaired growth and feed conversion from 4 to 46 d (P < 0.01) and increased incidence of leg disorders (P < 0.05), viscosity of jejunum content (P < 0.01), and jejunum length (P < 0.05). We concluded that rye in feed impaired broiler performance and increased digesta viscosity and incidence of leg disorders and that FR and ES reduced the magnitude of the problem. The beneficial effects of ES on bird performance were more evident when birds were fed AL.

Animal Feed↗
PubMed2003

Phase II study of carboplatin and 1-h intravenous etoposide and paclitaxel in a novel sequence as first-line treatment of patients with small-cell lung cancer.

PURPOSE: To evaluate the efficacy and tolerability of paclitaxel, carboplatin and etoposide when administered in combination to previously-untreated small-cell lung cancer (SCLC) patients. PATIENTS AND METHODS: Patients (n=95) with limited-stage disease (LSD; n=45) or extensive-stage disease (ESD; n=50) from 14 Spanish hospitals were entered into the study. Etoposide was administered 80 mg/m(2)/day intravenous (i.v.) on days 1, 2 and 3, paclitaxel 175 mg/m(2) i.v. on day 3 and carboplatin area-under-the-concentration-time-curve=6; i.v. on day 3, of a 3-week cycle, and repeated for up to 6 cycles. RESULTS: The overall response (OR) rate was 74% (n=70; 32 complete, 38 partial). Although the OR in LSD and ESD patients was similar (73 vs 74%, respectively), the percentage complete response was significantly higher among the former (49 vs 20%). The main toxicities were grade 3-4 neutropenia and febrile neutropenia (62 and 18%, respectively) and there were 3 toxic deaths. Other toxicities were rare or easily manageable. Disease-free survival and overall survival rates at 1 year were 53 and 70% in LSD and 18 and 39% in ESD patients, respectively. CONCLUSION: The results indicate that the combination of paclitaxel, etoposide and carboplatin has an anti-tumour activity in SCLC that is comparable to other combination regimens, and is well tolerated.

Adult↗
PubMed2003

Antimicrobial resistance among clinical isolates of Streptococcus pneumoniae isolated in four southern European countries (ARISE project) from adult patients: results from the cefditoren surveillance program.

From four southern European countries (Spain, Italy, Portugal, and Greece) 877 Streptococcus pneumoniae isolates were recovered from adult patients with respiratory tract infections between September 2000 and March 2001. The antimicrobial susceptibility to 11 antibiotics was determined in a central laboratory. Penicillin resistance was high in Greece (47.1%) and Spain (25.1%) but much lower in Portugal (7.9%) and Italy (4.8%). On the other hand, erythromycin resistance was high in Italy (38.5%) and Spain (36.2%) with no statistical difference with Greece (29.4%) but reaching significance (p <0.01) with Portugal (15.7%). Resistance to levofloxacin was low (1.5%) but present in Spanish and Italian isolates. Cefditoren, a new cephem antibiotic tested, was the most potent compound (MIC90 = 0.5 microg/ml) followed by levofloxacin and cefotaxime (MIC90 = 1 microg/ml). Given the high rates of penicillin and macrolide resistance reported, there is an evident need for new drugs and continued antimicrobial surveillance of S. pneumoniae.

Adolescent↗
PubMed1997

Pseudomigraine with temporary neurological symptoms and lymphocytic pleocytosis. A report of 50 cases.

This is the first large series, comprising 50 patients who suffered a total of 164 episodes, of pseudomigraine with temporary neurological symptoms and lymphocytic pleocytosis (PMP syndrome). Onset of PMP was between the ages of 14 and 39 years and was most frequent in males (68%). Eight males (24%) and five females (31%) had a personal history of migraine. One-quarter had had a viral-like illness up to 3 weeks prior to the onset of the syndrome. The clinical picture consisted of one to 12 episodes of changing variable neurological deficits accompanied by moderate-to-severe headache and occasionally fever. The headaches were described as predominantly throbbing and bilateral with variable duration (mean, 19 h). The mean duration of the transient neurological deficits was 5 h. Sensory symptoms were most common (78% of episodes), followed by aphasic (66%) and motor (56%) symptoms. Visual symptoms appeared in only 12% of episodes. The most frequent combinations were motor aphasia plus sensory and motor right hemibody symptoms (19% of episodes), motor aphasia plus right sensory symptoms (10%) and isolated right (9%) or left (9%) sensory symptoms. All patients were asymptomatic between episodes and following the symptomatic period (maximum duration 49 days). Lymphocytic pleocytosis ranged from 10 to 760 lymphocytic cells/mm3 CSF (mean, 199). In CSF, protein was increased in 96% of patients, IgG was normal in 80% of cases and oligoclonal bands were not found. Adensoine deaminase values were slightly above normal in two out of 16 patients tested. Extensive microbiological determinations, including viral HIV and borrelia serologies, were negative. Brain CT and MRI were always within normal limits, while EEG frequently showed focal slowing. Conventional cranial angiography was performed on 12 patients. In only one were there abnormalities suggestive of localized vascular inflammation, coincident with the focal neurological symptoms. Two patients developed PMP symptoms immediately after angiography. SPECT, performed on only three patients in the symptomatic period, revealed focal areas of decreased uptake consistent with the clinical symptoms. PMP aetiology remains a mystery; chronic arachnoiditis, viral meningoencephalitis or migraine are not plausible aetiological explanations. Because a number of patients had had a prodromic viral-like illness, we hypothesize here that such a viral infection could activate the immune system, thereby producing antibodies that would induce an aseptic inflammation of the leptomeningeal vasculature, possibly accounting for this clinical picture.

Adolescent↗
PubMed1991

Phase II trial of ifosfamide in recurrent and metastatic head and neck cancer.

Thirty-six patients with recurrent carcinoma of the head and neck and no prior exposure to chemotherapy were treated with Ifosfamide. This drug was administered, concomitantly with Mesna, as a 24-hr infusion at a dose of 5-6.25 g/m2 every 3 weeks. Objective activity in 32 evaluable patients was 28% (9/32, 95% C.I. 17%-39%); 40% of patients had leukocyte values less than 2000 mm3 and 6% platelets less than 50,000 mm3. Nonhematologic toxicity consisted mainly of nausea/vomiting (66% greater than or equal to grade 2) and alopecia (80% greater than or equal to grade 2). The activity encountered warrants further studies with this drug in head and neck cancer.

Adult↗
PubMed1984

Phase I trial of intermittent high-dose dacarbazine.

A phase I study was conducted with dacarbazine (DTIC) protected from light and administered iv as a single dose every 3 weeks. Eighteen patients received 47 courses of DTIC, with doses ranging from 850 to 1980 mg/m2. Hypotension was the dose-limiting toxic effect and it may be secondary to the citric acid present in the pharmaceutic preparation of DTIC. Sporadic myelosuppression was seen at doses greater than 1380 mg/m2. Other side effects noted were nausea and vomiting, acute diarrhea, headache, a "flu-like" syndrome, and a hypersensitivity reaction to sunlight. No antitumor activity was found. The results of this study indicate that this may be a qualitatively different way of giving DTIC, and that the side effects of this drug may be intermingled with those of citric acid in this particular schedule. If the conventional pharmaceutic preparation of this drug is not modified, further studies with high-dose DTIC protected from light should be discouraged.

Adult↗
PubMedDate not supplied

[Diagnostic considerations in unilateral hyperlucency of the lung (Swyer-James-MacLeod Syndrome)].

Swyer-James-MacLeod Syndrome (SJMS) is considered to be a relatively uncommon and complex disease characterized by roentgenographic hyperlucency of one lung, lobe, or part of a lobe, due the pulmonary vascular structure and alveolar overdistension. It is sometimes associated with bronchiectasis. This syndrome seems to be an acquired disease that develops after viral bronchiolitis and/or viral pneumonia in early childhood. Microscopically, there is evidence of patchy bronchitis and bronchiolitis.SJMS is usually asymptomatic and discovered accidentally by chest radiography in a child with respiratory symptoms and should be differentiated from other causes of unilateral hyperlucency on chest radiography, such as those related to congenital bronchial and/or vascular abnormalities. Treatment includes early control of lung infections, as well as influenza and pneumococcal vaccination. Few reports of this syndrome in children have been published. We describe the case of a 12-year-old boy with unilateral hyperlucency of the lung and respiratory symptoms of acute pneumonia and discuss the main diagnostic features of this syndrome.

Acute Disease↗
PubMedDate not supplied

[Quality control of general diets served in a county hospital].

INTRODUCTION: The general diet of a hospital, given to patients who do not require therapeutic modifications, must meet their nutritional demands. MATERIAL AND METHODS: During a 42 consecutive days period, the complete menu of a patient was randomly selected. Using a computer program based on the food composition tables, we verified whether or not the foods the patient received, met the requirements of the theoretical menus of the hospital, designed according to the international recommendations. RESULTS: The provided menus supplied 2,410 kilocalories, of which 900 (37.3%) corresponded to carbohydrates, 1,071 (44.4%) corresponded to lipids, and 439 (18.3%) corresponded to proteins. The level of cholesterol was 422 mg, and the fiber content was 20 g. These values differ significantly from the theoretical values noted previously: 2,200 kilocalories, 55% carbohydrates, 30% lipids, 15% proteins, cholesterol less than 300 mg, and 40 g of fiber (p < 0.001). Within the fats, the monounsaturated fats were the most abundant (45%). With regard to vitamins and minerals, vitamin D was the only deficient vitamin when compared to the international recommendations. CONCLUSION: We have detected that our general menus provide an excess of fats and cholesterol, as well as a deficient supply of carbohydrates, fiber, and vitamin D. We believe it necessary to carry out periodic quality controls to correct the defects that arise on translating the theoretical menus into daily practice.

Food Service, Hospital↗