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.

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.

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).

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.

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.

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.

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.

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.

Peptic ulcer in migrants. Seven case-reports from Italy.

Migrant workers in Central Europe are reported to suffer from an increased prevalence of both duodenal and gastric ulcer as compared to native population. No information is available, however, as far as Italy is concerned. The Authors have thought of interest to report on 7 cases of peptic ulcer disease occurring in migrant workers in Italy. Patients were young adult males from African or Mediterranean developing Countries. In 5 cases the symptoms of their peptic ulcers began after their arrival in Italy. The etiopathogenesis of peptic ulcer was likely to include an interaction among emotional stress, low income, shift and manual work, cigarette smoking and nonsteroidal antiinflammatory drugs self-administration. This last factor has not been reported in literature. The hypothesis that migrant workers in Italy are a peptic ulcer-prone population needs further confirmation for its clinical and social implications.

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.

Immunohistochemical study of the appearance of some markers in liver adjoining hepatocellular carcinoma.

The presence and distribution of AFP, AAT and HBsAg in peritumoral non-neoplastic hepatocytes (NNH) of 27 cases and, at the same time, in the neoplastic tissue of 37 liver cell carcinoma (HCC) were studied; AFP and HBsAg were more frequently found in NNH than in HCC cells; no differences were found for AAT. The presence of HBsAg also in normal liver without cirrhosis is probably best explained by its possible role in neoplastic transformation and by the inhibition of replication of the viruses AFP, considered to be expression of dedifferentiated cells, may possible be taken up by NNH for catabolic purposes.

IIB osteosarcoma. Current management, local control, and survival statistics--the Australian experience.

Current management of osteosarcoma at the authors' institution involves intraarterial induction chemotherapy using intermittent cycles of cisplatin and doxorubicin (Adriamycin), surgical resection with limb-sparing wherever possible, and adjuvant systemic chemotherapy (high-dose methotrexate with retrieval and doxorubicin). Twenty cases treated in this way between May 1983 and May 1989 are reviewed. There were 18 Stage IIB osteosarcomas and two Stage IIB malignant fibrous histiocytomas. Chemotherapeutic effect was evaluated in the resected tumors. There was little correlation between the clinical response to the induction chemotherapy and cell necrosis present in the resected tumor mass. Wide resection margins were achieved in 17 cases, a minimal margin in two, and a contaminated margin in one. Radiotherapy was used in these three cases where resection margin was in doubt. There were two local recurrences in these three cases. Four patients have died of their disease, and there was one treatment-related death. Overall probability of survival in this group of 20 patients has been expressed by the Kaplan-Meier method as 58%.

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.

[Acute intrathoracic respiratory infections in hospitalized children. Uruguay 1984-1986]. / Infecciones respiratorias agudas intratorácicas en niños hospitalizados. Uruguay 1984-1986.

Between may 1984 and november 1986, a study, which included 475 children under five years of age hospitalized due to acute intrathoracic respiratory infections, was carried out in order to obtain clinical, radiological and etiological characteristics which may aid in establishing norms to diagnose and treat these patients. Nasopharyngeal aspirations were performed on each child, while viral diagnosis was done through viral isolation techniques and indirect immunofluorescence. The presence of a virus was detected in 34.4% of the cases and in 28.8% of a subsample. A precoded questionnaire was used to obtain the clinical information needed and all X-rays were reviewed by the same radiologist using simple pre-established criteria. A comparison was made on the similarities found between both the clinical and radiological diagnosis, as well as the sensitivity and specificity of some of the clinical signs which characterize bronchiolitis and the pneumoniae.

Hemoductal pancreatitis secondary to gastroduodenal artery-ruptured pseudoaneurysm: a rare cause of hematemesis.

A 65-yr-old alcoholic man with a history of calcific pancreatitis presented with massive hematemesis complicated by lipothymia. Physical examination disclosed stigmata of chronic liver disease. The laboratory picture was predominantly of cholestatic type with impaired liver protein synthetic activity. Emergency esophagogastroduodenoscopy was unable to provide definitive diagnosis, but reendoscopy with a side-viewing duodenoscope revealed active bleeding through the ampulla of Vater. An ultrasound examination showed a large, complex pancreatic lesion that computed tomography showed to be a pancreatic pseudocyst with an inside pseudoaneurysm. A visceral angiography revealed an anomalous arising of the common hepatic artery from the superior mesenteric artery and a pseudoaneurysm of the gastroduodenal artery at its origin. A second massive hemorrhage required an emergency operation, and surgical liver biopsy revealed focal steatosis. In conclusion, bleeding of a pancreatic pseudoaneurysm may be massive but intermittent, and side-viewing duodenoscopy, even prolonged, is essential in the diagnosis.

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.

Serum CA 19-9 in the postsurgical follow-up of patients with pancreatic cancer.

In the last few years serum CA 19-9 has been shown to be a highly sensitive marker of pancreatic adenocarcinoma. This study assesses the value of serum CA 19-9 assay in the postsurgical follow-up of patients undergoing pancreatic cancer resection. In 14 patients with cancer in the head of the pancreas and abnormal preoperative serum CA 19-9 values (greater than 40 U/ml), a pancreatoduodenectomy was performed. In all patients the CA 19-9 antigen was immunohistochemically demonstrated on the removed tumoral tissue. Postoperative serum CA 19-9 concentrations were serially measured 15 days after surgery and then every other month. Serum CA 19-9 scores returned to the normal range only in 7 (50%) of the resected patients. All patients with a normal postoperative value and none of those with a persistently elevated one survived longer than 7 months. Early postoperative serum CA 19-9 assay was superior to perioperative staging of the tumor as a prognostic index. All of the seven patients with postoperative normal values exhibited a subsequent increase within 16 months. In all cases the elevation of CA 19-9 occurred at least 2 months before ultrasound (US) could detect local recurrences of hepatic metastasis. Our data indicate that a normal early postoperative CA 19-9 score is a relatively favourable prognostic index in patients who undergo radical surgery for pancreatic cancer and that the CA 19-9 test can be used, as an early marker of recurrence, in monitoring these patients.