The CeFe11Ti permanent magnet: a closer look at the microstructure of the compound.

High-performance permanent magnets (PM) are compounds with outstanding intrinsic magnetic properties. Most PMs are obtained from a favorable combination of rare earth metals (RE = Nd, Pr, Ce) with transition metals (TM = Fe, Co). Amongst them, CeFe11Ti claims considerable attention due to its large Curie temperature, saturation magnetization, and significant magnetocrystalline anisotropic energy. CeFe11Ti has several potential applications, in particular, in the development of electric motors for future automatic electrification. In this work, we shed some light on the mictrostructure of this compound by performing periodic hybrid-exchange density functional theory (DFT) calculations. We use a combined approach of atom-centered local orbitals, plane waves and full-potential linear muffin-tin orbital (LMTO) for our computations. The electronic configuration of the atoms involved in different steps of formation of the crystal structure of CeFe11Ti gives an explanation on the effect of Ce and Ti on its magnetic properties. While Ti stabilizes the structure, atomic orbitals of Ce hybridizes with Fe atomic orbitals to a significant extent and alters the electronic bands. Our calculations confirm a valence of 3+ for Ce, which has been deemed crucial to obtain a large magnetocrystalline anisotropy. In addition, we analyze several spin configurations, with the ferromagnetic configuration being most stable. We compare and contrast our data to those available and provide an insight for further development of optimized high-performance PMs. Moreover, we compute the Magnetocrystalline Anisotropy of this compound by means of two approaches: the Force Theorem and a full-potential LMTO method.

Stereotactic radiation therapy in oligometastatic colorectal cancer: outcome of 102 patients and 150 lesions.

To evaluate the local control (LC), progression free survival (PFS), out-field PFS, overall survival (OS), toxicity and failure predictors of SRT in a series of various sites oligometastatic CRC patients. Patients with oligometastatic CRC disease were analyzed retrospectively. The SRT prescribed dose was dependent on the lesion volume and its location. 102 consecutive oligometastatic CRC patients (150 lesions) were included. They underwent SRT between 2012 and 2015. Median prescription dose was 45 Gy (median dose/fraction was 15 Gy/3 fractions biological equivalent dose (BED10) 112.5 Gy). Median follow-up was 11.4 months. No patients experienced G3 and G4 toxicity. No progression was found in 82% (radiological response at 3 months) and 85% (best radiological response) out of 150 evaluable lesions. At 1 and 2 years: LC was 70% and 55%; OS was 90% and 90%; PFS was 37% and 27%; out-field PFS was 37% and 23% respectively. Progressive disease was correlated with BED10 (better LC when BED10 was ≥ 75 Gy (p < 0.0001)). In multivariate analysis, LC was higher in lesions with a Plpnning target volume (PTV) volume < 42 cm3 and BED10 ≥ 75 Gy. Patients with Karnofsky performance status < 90 showed higher out-field progression. SRT is an effective treatment for patients with oligometastases from CRC. Its low treatment-associated morbidity and acceptable LC make of SRT an option not only in selected cases. Further studies should be focused to clarify which patient subgroup will benefit most from this treatment modality and to define the optimal dose to improve LC while maintaining low toxicity profile.

Quantum-mechanical ab initio simulation of the Raman and IR spectra of Fe3Al2Si3O12 almandine.

The IR and Raman spectra of the Fe(3)Al(2)Si(3)O(12) almandine garnet were simulated using the periodic CRYSTAL code with an all-electron Gaussian-type basis set and the hybrid B3LYP functional. The wavenumbers of the 25 Raman-active modes (3 of A(1g), 8 of E(g), and 14 of F(2g) symmetry) and 34 F(1u) IR-active modes (17 TO and 17 LO) were computed, as were the IR intensities. Calculated wavenumbers are in excellent agreement with the various sets of experimental results, with the mean absolute difference |Delta| being between 4 and 8 cm(-1). Graphical animation, available on the CRYSTAL Web site, provides a very comprehendible description of the movement of atoms and groups in each vibrational mode. The simulated reflectivity spectrum, obtained using a classical dispersion relation, is in excellent agreement with the measured one.

Functionalization of ceramic tile surface by sol-gel technique.

The aim of this investigation was the surface functionalization of industrial ceramic tiles by sol-gel technique to improve at the same time the cleanability of unglazed surfaces. This objective was pursued through the design and preparation of nanostructured coating that was deposited on polished unglazed tiles by air-brushing. In particular TiO(2)-SiO(2) binary film with 1, 2 or 5wt% of titania were prepared by using tetraethoxysilane and titania nanoparticles as precursors. The obtained films were characterized by scratch tests to verify the adhesion of the coatings to the polished tiles. To mainly evaluate the effect of the thermal treatment (temperature range 100-600 degrees C) on the photocatalicity of the coatings, the films were studied under UV exposure by contact angle measurements and cleanability test. Particular attention has been paid to preserve the aesthetical aspect of the final product and the obtained hue variation was evaluated by means of UV-visible spectroscopy and colorimetric analysis.

Synthesis of chromium containing pigments from chromium galvanic sludges.

In this work the screening results of the scientific activity conducted on laboratory scale to valorise chromium(III) contained in the galvanic sludge as chromium precursor for ceramic pigments are reported. The valorisation of this waste as a secondary raw material (SRM) is obtained by achievement of thermal and chemical stable crystal structures able to color ceramic material. Two different pigments pink CaCr(0.04)Sn(0.97)SiO(5) and green Ca(3)Cr(2)(SiO(4))(3) were synthesized by solid-state reactions using dried Cr sludge as chromium oxide precursor. The obtained pigments were characterized by X-ray diffraction and SEM analysis. Furthermore the color developed in a suitable ceramic glaze was investigated in comparison with the color developed by the pigments prepared from pure Cr(2)O(3). The characterization carried out corroborates the thermal and chemical stability of the synthesized pigments and, especially for the Cr-Sn pink pigment, the powders develop an intense color that is very similar to the color developed by the pigments obtained starting from pure Cr(2)O(3).

La muerte posneonatal en domicilio diez años después: Montevideo, 2006 / Postneonatal household death 10 years after: Montevideo, 2006

Introducción: estudios nacionales de 1996 mostraron una alta prevalencia de muertes sin asistencia en el período posneonatal. En los diez años siguientes bajó la tasa de mortalidad infantil a expensas del componente posneonatal. En el nuevo contexto epidemiológico es de interés investigar si la muerte posneonatal en domicilio ha modificado sus características. Objetivos: 1. Conocer la mortalidad posneonatal en domicilio en Montevideo en 2006, describir algunas características de la población afectada y su ambiente. 2. Conocer las causas a las que se atribuyeron las muertes y los procedimientos diagnósticos utilizados. 3. Comparar los resultados con los de 1996.Material y método: se realizó un estudio descriptivo y retrospectivo que incluyó todos los residentes en Montevideo fallecidos en domicilio en el período posneonatal en 2006. Las fuentes fueron: certificados de defunción, partes policiales, informes de autopsia y de estudios anátomo-patológicos. Se usó el mismo formulario de recolección de datos que en 1996. En los casos en que se dispuso de informe de Anatomía Patológica se revisó la causa de muerte asignada inicialmente. Resultados: en 2006, en Montevideo hubo 84 muertes posneonatales, 39 (0,46) de ellas en domicilio. Predominaron los varones (0,64). La mediana de edad fue 3 meses y 15 días. Se obtuvo la relación peso/edad según sexo en 34 casos: ocho fueron iguales o inferior al percentil 5. Exceptuada la desnutrición y la prematurez, en la mayoría de los casos (0,67) no se conocían antecedentes patológicos. Seis eran portadores de enfermedades conocidas y otros siete cursaron cuadros respiratorios en la semana anterior a la muerte. En ladistribución estacional predominó el invierno (0,36). Casi todas las muertes fueron naturales y certificadas por médico forense. En 24 de las 38 muertes naturales se solicitó un estudio anátomo-patológico complementario. Si se toman en cuenta los resultados de la autopsia judicial, los estudios anátomo-patológicos y ...

Experimental and theoretical study of a surface stabilized monolayer phase of nickel oxide on Pd(100).

A surface stabilized monolayer phase of nickel oxide, c(4 x 2)-Ni(3)O(4), has been found to grow epitaxially under reactive deposition conditions on Pd(100), in the presence of other adsorbed phases and in competition with them. High-quality scanning tunneling microscopy data are reported and discussed, including a detailed analysis of the defects and of the border morphology of this new phase. The data are discussed in the light of ab initio simulations of the electronic, energetic, and geometric properties of such a phase. A hybrid-exchange density functional theory approach has been used, and a slab model is adopted where palladium is simulated by a thin film covered on both sides by regular epilayers. A growth model has been developed that explains both the unusual stoichiometry of the phase and the observed defects.

Vigilancia del uso de antibióticos en el Hospital Pediátrico del Centro Hospitalario Pereira Rossell: susceptibilidad antimicrobiana; gasto y consumo de antibióticos / Vigilance of antibiotic use in a pediatric hospital (Hospital Pediátrico del Centro Hospitalario Pereira Rossell): antimicrobial susceptibility; cost and consumption antibiotics

Introducción: el uso de guías para el tratamiento antibiótico empírico constituye una estrategia fundamental para contener el aumento sostenido en la resistencia bacteriana y en los gastos en antibióticos. En 1998, en el Hospital Pediátrico del Centro Hospitalario Pereira Rossell se adecuaron las guías de antibioticoterapia empírica par alas infecciones más frecuentes asistidas en salas generales y en emergencia, en base a la epidemiología local. Desde esa fecha se comenzó la vigilancia deel uso de antibióticos. Objetivos: analizar los resultados de esta vigilancia sobre el gasto y el consumo de antibióticos y sobre la susceptibilidad antimicrobiana. Metodología: se determinó el gasto generado por los antibióticos recomendados en las guías de atención hospitalaria, en salas generales y en emergencia (penicilina, aminopenicilinas, cefalosporinas, macrólidos). Para estimar el consumo en pacientes hospitalizados se calculó la dosis diaria definida (DDD)/100 camas día para cada uno de los antibióticos. Se compararon los resultados de gasto y consumo 2001-2. Se comparó la susceptibilidad antimicrobiana de los gérmenes más frecuentes del período 2001-2 con la previa a la adecuación de las guías terapéuticas. Resultados: los antibióticos recomendados representaron enel año 2001, 57 por ciento del gasto en antibióticos (2.206.652,57 pesos) y en 2002, 54 por ciento (1.441.280 pesos). Los antibióticos más usados fueron las animopenicilinas. El consumo de cefuroxime intravenoso disminuyó 60 por ciento (de 13.1 a 5.36 DDD/100 camas-día). El consumo de ceftriaxona intravenosa y de amoxicilina oral aumentó 38 por ciento y 16 por ciento, respectivamente. Para el resto de los antibióticos el consumo se mantuvo constante. Las tasas de susceptibilidad antimicrobiana de los gérmenes más frecuentes (S. pneumoniae, S. aureus, E, coli, Shigella spp) a los antibióticos recomendados en las guías terapéuticas se mantuvieron por encima de 80 por ciento. Conclusiones: estos son los primeros resultados de la vigilancia del uso ded antibióticos en este hospital y demuestran la vigencia y la aceptación de las guías de antibióticoterapia empírica propuestas. Es difícil interpretar la disminución del gasto en antibióticos debido a la variación en el precio de estos medicamentos en este período.

Electropherotypes of rotaviral RNA from cases of infantile diarrhea in Uruguay.

Electropherotypes of human rotavirus isolates from infants with acute diarrhea belonging to two populations with different clinical features were determined. Thirteen electropherotypes were identified in total 69 isolates; 46 (66.6%) isolates had long RNA migration patterns and 23 (33.3%) isolates had short migration pattern. One of the long-pattern electropherotypes (47.82% of the total electropherotypes) was predominant. It was detected in both populations almost throughout the whole period of the study, while other electropherotypes were found only occasionally. The co-circulation of long and short electropherotypes was not frequent.

Identification of defect sites on MgO(100) thin films by decoration with Pd atoms and studying CO adsorption properties.

CO adsorption on Pd atoms deposited on MgO(100) thin films has been studied by means of thermal desorption (TDS) and Fourier transform infrared (FTIR) spectroscopies. CO desorbs from the adsorbed Pd atoms at a temperature of about 250 K, which corresponds to a binding energy, E(b), of about 0.7 +/- 0.1 eV. FTIR spectra suggest that at saturation two different sites for CO adsorption exist on a single Pd atom. The vibrational frequency of the most stable, singly adsorbed CO molecule is 2055 cm(-)(1). Density functional cluster model calculations have been used to model possible defect sites at the MgO surface where the Pd atoms are likely to be adsorbed. CO/Pd complexes located at regular or low-coordinated O anions of the surface exhibit considerably stronger binding energies, E(b) = 2-2.5 eV, and larger vibrational shifts than were observed in the experiment. CO/Pd complexes located at oxygen vacancies (F or F(+) centers) are characterized by much smaller binding energies, E(b) = 0.5 +/- 0.2 or 0.7 +/- 0.2 eV, which are in agreement with the experimental value. CO/Pd complexes located at the paramagnetic F(+) centers show vibrational frequencies in closest agreement with the experimental data. These comparisons therefore suggest that the Pd atoms are mainly adsorbed at oxygen vacancies.

Etiology of children's diarrhea in Montevideo, Uruguay: associated pathogens and unusual isolates.

We studied microorganisms associated with infant diarrhea in a group of 256 children admitted to a public pediatric hospital in Montevideo, Uruguay. Diagnostic procedures were updated to optimize detection of potential pathogens, which were found in 63.8% of cases, and to be able to define their characteristics down to molecular or antigenic type. Coinfection with two or more agents was detected in more than one-third of positive studies. Escherichia coli enteric virotypes, especially enteropathogenic E. coli (EPEC), were shown to be prevalent. Rotavirus, Cryptosporidium, Campylobacter (mainly Campylobacter jejuni), and Shigella flexneri were also often identified. Enterotoxigenic E. coli, Salmonella, and Giardia lamblia were sporadically recognized. Unusual findings included two enteroinvasive E. coli strains, one Shigella dysenteriae 2 isolate, and a non-O:1 Vibrio cholerae culture. EPEC bacteria and S. flexneri (but not Salmonella) showed unusually frequent antimicrobial resistance, especially towards beta-lactam antibiotics, which is the subject of ongoing work.

Standard case management of pneumonia in hospitalized children in Uruguay, 1997 to 1998.

OBJECTIVE: To report the results of the use of antimicrobial guidelines for the management of children with community-acquired bacterial pneumonia. METHODS: Admittance and discharge criteria and algorithms for diagnosis and treatment were established. The decision to treat with antibiotics was based on radiologic findings in pneumonia with pulmonary consolidation and left to the attending physician's criteria in the remaining cases. The use of antibiotics was limited to penicillin and derivatives (ampicillin, amoxicillin) and macrolides. RESULTS: Of the 1163 children treated as bacterial pneumonia, hospitalized in public and private health facilities in Montevideo from September, 1997, through September, 1998, standard case management was applied in 1082 (93%). Age distribution was: <1 month, 1%; between 1 and 11 months, 29%; between 1 and 5 years, 50%; >5 years, 20%. Chest radiography showed evidence of pulmonary consolidation in 843 children (73%). Bacteria were detected in blood culture and/or pleural fluid of 57 children (5%). In 51 the identified microorganism was Streptococcus pneumoniae, susceptible to penicillin in 30, intermediate in 6 and resistant in 5 (maximum MIC, 4 microg/ml); in 10 cases etiologic diagnosis was made by antigen detection. Empyema was present in 62 children (5.3%); 38 (3.27%) required treatment in an intensive care unit; and 5 (0.4%) died. CONCLUSIONS: Compliance with standard case management was highly satisfactory. Outcome of children treated with penicillin and derivatives was good, including children with empyema and pneumatocele and two patients with penicillin-resistant S. pneumoniae. At the present time S. pneumoniae resistant to penicillin is not an important problem in children with pneumonia in Uruguay. Surveillance of identified microorganisms and their antimicrobial susceptibility must continue.

An additional structural and electrical study of polymeric haloplumbates(II) with heterocyclic diprotonated amines.

The crystal structures of three polymeric bidimensional piperazinium, N,N'-dimethylpiperazinium, and N-benzylpiperazinium hydrate haloplumbates(II) and one polymeric monodimensional N,N'-dimethylpiperazinium hydrate haloplumbate(II) were determined by means of X-ray analysis. The (pipzH2)[PbCl4] salt is monoclinic, space group P2(1)/c, with a = 5.778(2) A, b = 22.612(26) A, c = 9.061(4) A, beta = 95.37(6) degrees, Z = 4; (me2pipzH2)[PbBr4] crystallizes in the monoclinic P2(1) space group with a = 6.101(3) A, b = 18.822(12) A, c = 6.229(2) A, beta = 98.62(4) degrees, Z = 2; the crystals of (me2pipzH2)2[Pb3I10].4H2O are monoclinic, space group P2(1)/c, a = 19.054(4) A, b = 12.239(3) A, c = 18.273(4) A, beta = 93.42(12) degrees, Z = 4; (benzpipzH2)3[Pb2Br10].2H2O crystallizes in the monoclinic P2(1)/c space group with a = 22.380(22) A, b = 9.304(15) A, c = 24.577(25) A, beta = 94.28(11) degrees, Z = 2. Different model type structures, such as one-dimensional linear chain, ribbonlike, and perovskite-like, were observed, and factors governing these structural arrangements are pointed out. The compounds were also investigated by means of thermal and electrical measurements, and correlations between electrical properties and crystal structures were noted.

Study of the vibrational spectrum of cuprorivaite.

In this research, after tracing a history of the pigment, the preparation and analysis of samples of Egyptian blue have been reported. The main reactions taking place during its preparation are indicated. X-ray diffractions show that, starting from mixtures of precursors with stoichiometric composition, the product is practically only cuprorivaite. The kind of flux and cristallinity of silica does not seem determining factors for the pigment formation. Infrared and Raman spectra and an assignment of the bands are reported. Impurities ascertained are discussed on the basis on the data available.

Synthesis and cytotoxicity of bis(benzo[g]indole-3-carboxamides) and related compounds.

A series of bis(benzo[g]indoles) bridged by CX-(CH2)nN(Me)(CH2)n-CX (X = O, S, H2; n = 2,3) was synthesized as bifunctional antitumor agents and evaluated for cytotoxic activity against diverse human cancer cell lines by the National Cancer Institute. The parent compounds 2a,b exhibited a good level of activity and derivates 2c-g,i,k demonstrated significant inhibitory effects, all with IC50 values in the low micromolar range. The thioamide analogue 2j showed less potency. It is interesting to note that introduction of substituents on the benzene ring of the benzo[g]indole portion of 2a,b did not affect activity, with the only exception of the 7,8-dichloro derivative 2h which became less potent. One member of this series, 2i, was then tested in the hollow fiber cell assay to evaluate, in a preliminary fashion, its in vivo antineoplastic activity. Molecular modelling studies were performed on amide 2a and thioamide 2j to explain the loss of activity of 2j as to 2a. Finally, compound 2a behaved as a typical DNA intercalating agent, as judged from viscosity measurements with Poly(dA-dT)...poly(dA-dT).

Preparation of thieno[3,2-h]cinnolinones as matrix metalloproteinase inhibitors.

A new series of thieno[3,2-h]cinnolinone analogues was synthesized which is structurally related to 2,3,4,4a,5,6-hexahydrothieno [3,2-h]cinnolin-3-one 1, a weak inhibitor of the matrix metalloproteinase MMP-8 (human neutrophil collagenase). Preliminary SAR studies have shown that while C4a-methyl, C7-acetylamino, C7 and C8-nitro substitution, and C4-C4a olefination provided no increase in activity relative to 1, C8-acetylamino substitution as in 5 and 8 was favourable. Moreover, to predict how the thieno[3,2-h]cinnolinone inhibitors might bind to MMP-8, the unsubstituted compound 9 was docked into the MMP-8 crystal structure. These studies revealed that inhibitor 9 does not seem to be able to coordinate the catalytically-active zinc ion but preferably interact with the peptide-binding region of the active site.

Chronic dexamethasone treatment and its effects on sensory neuropeptides, pulpal injury reactions and reparative dentin.

Initial sensory nerve reactions to dental injuries include terminal sprouting and intensified immunoreactivity for calcitonin gene-related peptide (CGRP) and substance P (SP); those reactions are reduced at 4 days after injury when rats are treated daily with dexamethasone (DEX) [17]. Here we have analyzed long-term effects of DEX (daily, 0.2 mg/kg) on wound healing, sensory nerve sprouting, and CGRP/SP intensity at 7-14 days after cavity preparation. All DEX treated rats had loss of appetite and stopped growing during the postoperative periods while controls had normal postoperative growth. After 7-14 days, CGRP immunoreactivity (IR) was decreased to one-third of normal (P < 0.05) compared to vehicle in both the intact and injured molar pulp, and SP also decreased, but the neuropeptide intensity in adjacent periodontal innervation was not changed. Pulpal injury and inflammation were reduced by DEX treatment, but reparative dentin was formed just as well in the DEX rats as in the vehicle group. When the injured teeth formed fibrous dentin, there was sprouting of nerves towards that matrix, and DEX did not inhibit that reaction. The sprouts could contain intense neuropeptide immunoreactivity in DEX rats even though the CGRP/SP intensity in uninjured pulp was reduced. We conclude that (1) chronic DEX treatment causes a generalized decrease in CGRP and SP neuropeptides in pulpal nerves but not in periodontal ligament; (2) it reduces abscess formation in injured teeth; (3) it does not block reparative dentin formation; and (4) it does not block sprouting of pulpal nerves towards fibrous dentin. The selective loss of pulpal neuropeptides CGRP and SP during dexamethasone treatment may be caused by reduced dental function since there was substantial loss of appetite and chronic weight loss during the 1-2 week treatment periods.

Combined endoscopic and surgical management of Dieulafoy vascular malformation.

BACKGROUND: Dieulafoy's disease (exulceratio simplex) is an uncommon cause of gastric hemorrhage as a result of an abnormally large, submucosal, eroded gastric artery, often located in the upper part of the stomach. It represents a clinical challenge because of the intermittent nature of massive bleeding accounting for a constantly fatal course in conservatively (nonsurgically or nonendoscopically) treated patients. Published therapeutic options include techniques of endoscopic hemostasis or operative procedures. STUDY DESIGN: Herein we report two patients in whom a combined endoscopic and operative approach was performed to obtain a definitive prevention of rebleeding and an undoubted anatomopathologic diagnosis. RESULTS: Our innovative combined endoscopic and operative approach has offered three significant advantages: endoscopic preoperative diagnosis and control of the bleeding; valid aid in the intraoperative localization of hemorrhagic lesions, which is erratic intraoperatively, requires gastrotomy, and prolongs the duration of operation; and endoscopy-guided limited wedge resection as opposed to standard techniques involving gastrotomy for simple ligation or oversewing of the involved vessel, local excision, or wide wedge resections that used to be recommended until the recent past. CONCLUSIONS: We confirm that seemingly obscure origins of massive recurring hemorrhage of the upper part of the gastrointestinal tract should increase the suspicion of Dieulafoy's disease, prompting careful examination of the gastric fundic area and greater curvature. Endoscopic hemostasis is the first choice; whenever operative treatment is indicated (because of the endoscopic or clinical situation), it should be as conservative as possible because of intraoperative endoscopic localization of the bleeding source.

Are routine duodenal and antral biopsies useful in the management of "functional" dyspepsia? A diagnostic and therapeutic study.

Fifty-three patients with previously uninvestigated chronic dyspepsia symptoms in the absence of gastrointestinal or extra-gastrointestinal disease (functional dyspepsia) underwent antral and duodenal mucosal biopsies to detect the role of such samplings in the presence of normal endoscopic findings. Patients were enrolled in a randomized, placebo-controlled, double-blind trial, receiving either eradicating treatment (colloidal bismuth subcitrate plus metronidazole) or placebo if they had Helicobacter pylori-associated gastritis (20 patients), or cisapride or placebo if they had normal antral mucosa (28 cases). Unsuspected celiac sprue was found in one patient. Eradicating treatment ameliorated histological gastritis (p = 0.01). However, owing to great placebo efficacy, symptom remission rates following a 1-month wash-out period in both treatment groups were no higher than that in controls. Independent of the initial randomization, an extremely low symptom recurrence rate was observed during a drug-free follow-up study equivalent to the mean duration of symptoms before enrollment. We conclude that in functional dyspepsia, bulbar and antral biopsies are not useful in clinical management, equivalent symptom relief can be achieved in patients randomly assigned to both drugs and placebos, and such improvement can be long lasting in the absence of any maintenance treatment. We believe the prevalence of unsuspected villous atrophy and the therapeutic role of investigation-based reassurance deserve further assessment.