Development of metal - SiO2 nanocomposites in a single-step process by the polymerizable complex method

This work presents the synthesis and characterization of SiO2:metal (Ni, Co, Ag, and Fe) nanocomposites processed by the polymerizable complex method. The polymeric precursor solutions obtained were characterized by means of FT-Raman and C-13 NMR spectroscopy. The results show the formation of a hybrid polymer with carbon and silicon in the macromolecule chain and the transition metal cation arrested within this polymeric chain. The nanocomposites are formed during the controlled polymeric precursor pyrolysis. The reduction of the metal cation is promoted by the CO/CO2 atmosphere resulting from the pyrolysis of the organic material. Microstructural characterization, performed by TEM and X-ray diffraction (XRD), showed that the nanocomposites are formed by metal nanoparticles embedded in a amorphous matrix formed by SiO2 and carbon. In the SiO2:Fe system, Fe3C was also detected by XRD.

Oncology research and clinical decisions based on immunohistochemistry: the importance of the technical aspects that support a complex method

Immunohistochemistry (IHC) is the group of techniques that use antibodies as specific reagents to identify and demonstrate several cell and tissue components that are antigens. This linking allows locating and identifying the in situ presence of various substances by means of color that is associated with the formed antigen-antibody complexes. The practical value of this biotechnology area, widely used in Pathology and Oncology, in diagnostic, prognostic, theranostic and research context, results from the possibility of combining a colour marker with an antibody without causing any damage to specific binding established between antibody and antigen. This provides the microscopic observation of the target locations where the antibody and hence the antigen are present. IHC is presented as a powerful means for identification of several cellular and tissue structures that can be associated with pathologies, and of the consequences, at functional and morphological level, of these same elements action.

Synthesis of YAP phase by a polymeric method and phase progression mechanisms

The phase formation kinetics of YAP (YAlO(3)) synthesized through the polymeric precursor method was investigated by thermal analysis, X-ray diffraction and FT-IR spectroscopy. We demonstrated that the YAP synthesis is highly dependent on the heat and mass transport during all stages of the synthesis route. In the first stages, during the preparation of amorphous precursor, ""hot spots"" need to be suppressed to avoid the occurrence of chemical inhomogeneities. Very high heating rates combined with small amorphous particles are advantageous in the last stage during the formation of crystalline phase. We were able to synthesize nanosized particles of YAP single phase at temperatures around 1100 A degrees C for future preparation of phosphors or ceramics for optics.

A efectividade da intervenção da fisioterapia nas disfunções crânio- cervico-mandibulares

Introdução: As teorias etiológicas recíprocas que relacionam as disfunções da articulação temporo mandibular (ATM) com as disfunções da coluna cervical, os seus critérios de diagnóstico e formas de tratamento, não reúnem consenso, constituindo, actualmente, uma temática de debate e investigação. Objectivo: Descrever a avaliação e intervenção em fisioterapia, e os seus resultados numa utente com disfunção do complexo crânio-cervico-mandibular. Métodos: Foi realizado um estudo observacional descritivo, do tipo estudo de caso, reportando-se a uma enfermeira, de 28 anos, com quadro sintomatológico compatível com disfunção crânio-cervico-mandibular, com antecedentes de condilectomia e artroplastia da ATM, aos 14 anos. Inicialmente a utente apresentava dor irradiada na região cervical (7/10) e limitação dos movimentos articulares da coluna cervical. Referia, também, dor na região do ptérion direito (6/10), limitação dos movimentos da mandíbula, desvio lateral na abertura da boca e dificuldades funcionais na mastigação. A avaliação inicial e final (após tratamento), foi efectuada recorrendo-se à utilização do Goniometro CROM e da Therabite Range of Motion Scale, para medição das amplitudes articulares da cervical e ATM, respectivamente; Estetoscópio, para avaliação dos sons articulares da ATM; Escala Visual Analógica para graduação da dor. A intervenção decorreu ao longo de 10 sessões, bissemanais. No tratamento, foram aplicadas técnicas sobre os trigers points da musculatura cervical e músculos da mastigação; Mobilização passiva da cervical e ATM; Manipulação dos segmentos vertebrais cervicais e torácicos; Streching e técnicas de energia muscular; Técnicas funcionais para a ATM; Técnicas miofasciais para a coluna cervical e ATM; Exercícios de controlo motor da coluna cervical. Resultados: No final do tratamento, as amplitudes dos movimentos cervicais estavam completas e sem dor (0/10), mantendo, sensibilidade dolorosa à palpação das espinhosas de C5-C6 (1/10). Relativamente à ATM, verifica-se a abolição da dor (0/10) e a ausência do desvio lateral da mandíbula na abertura da boca, bem como, o aumento das amplitudes de movimento na abertura da boca (33 para 36 mm), e no desvio lateral esquerdo (2 para 2,8 mm). Conclusão: os resultados sugerem que a intervenção, com recurso a técnicas de terapia manual, no caso em estudo, parecem surtir efeitos positivos no quadro sintomatológico e funcional da utente.

Estimation of sex and age of "virtual skeletons"--a feasibility study.

This article presents a feasibility study with the objective of investigating the potential of multi-detector computed tomography (MDCT) to estimate the bone age and sex of deceased persons. To obtain virtual skeletons, the bodies of 22 deceased persons with known age at death were scanned by MDCT using a special protocol that consisted of high-resolution imaging of the skull, shoulder girdle (including the upper half of the humeri), the symphysis pubis and the upper halves of the femora. Bone and soft-tissue reconstructions were performed in two and three dimensions. The resulting data were investigated by three anthropologists with different professional experience. Sex was determined by investigating three-dimensional models of the skull and pelvis. As a basic orientation for the age estimation, the complex method according to Nemeskéri and co-workers was applied. The final estimation was effected using additional parameters like the state of dentition, degeneration of the spine, etc., which where chosen individually by the three observers according to their experience. The results of the study show that the estimation of sex and age is possible by the use of MDCT. Virtual skeletons present an ideal collection for anthropological studies, because they are obtained in a non-invasive way and can be investigated ad infinitum.

Litiumin talteenotto väkevistä kloridiliuoksista solvatoivilla uuttoreagensseilla

Tämän kandidaatintyön tarkoituksena oli selvittää voidaanko litiumia erottaa suolaliuoksesta solvatoivien uuttoreagenssien avulla suoraan ilman tavanomaisia monivaiheisia prosesseja. Kirjallisessa osassa esitellään neste-nesteuuton periaatteet ja tarkastellaan litiumin talteenotossa käytettyjä uuttomenetelmiä sekä litiumin merkitystä yhteiskunnallisti. Kokeellisessa osassa tutkittiin litiumin uuttoa litiumtetrakloroferraattina vesiliuoksesta, jonka koostumus oli lähellä Argentiinan Rinconin alueen suolajärvien vettä sisältäen litium-, kalsium-, magnesium-, sekä natriumkloridia. Kokeet suoritettiin erotussuppiloissa huoneenlämmössä käyttäen orgaanisena faasina tributyylifosfaatin (TBP) ja kerosiini, tributyylifosfaatin ja di-isobutyyliketonin sekä tributyylifosfaatin ja metyyli-isobutyyliketonin seoksia. Kullakin orgaanisella faasilla tehtiin kaksi koesarjaa. Ensimmäisessä vaihdettiin liuoksen [Fe3+]/[Li+]-suhdetta orgaanisen faasin TBP-pitoisuuden ollessa vakio. Toisessa muutettiin orgaanisen faasin TBP-pitoisuutta [Fe3+]/[Li+]-suhteen pysyessä vakiona. Litium saatiin talteenotettua hyvin selektiivisesti magnesiumin ja kalsiumin suhteen. Rautakonsentraation lisäyksen huomattiin lisäävän litiumin saantoa, mutta suurilla rautakonsentraatioilla selektiivisyys oli huonompi. Litiumia ei saatu erotettua kovin tehokkaasti, johtuen todennäköisesti suuresta natriumkonsentraatiosta. Suurin osa natriumista tulisi poistaa ennen uuttoa. Jos natriumin saisi poistettua tehokkaasti ennen uuttoa, voisi tutkittu menetelmä olla huomattavasti nopeampi verrattuna perinteiseen monivaiheiseen litiumin talteenottoprosessiin. Menetelmän huonona puolena on kuitenkin sen suuri raudan kulutus

Mécanismes neuronaux médullaires, coordination musculaire et fonction motrice chez les sujets hémiparétiques

Dans l’hémiparésie consécutive à un AVC, une coactivation anormale des extenseurs du genou et de la cheville est souvent observée à la jambe atteinte lorsque la personne tente de bouger ou encore lors de la marche. Les mécanismes sous-jacents à cette coactivation sont mal compris. Bien que l’AVC entraîne une lésion supraspinale, des évidences démontrent le dysfonctionnement de certains circuits spinaux dans l’hémiparésie. Ce projet de doctorat visait à évaluer : 1) l’excitabilité des circuits spinaux intersegmentaires projetant des extenseurs du genou aux extenseurs de la cheville et 2) si un éventuel dysfonctionnement de ces circuits dans l’hémiparésie est associé à une coactivation anormale des extenseurs du genou et de la cheville lors de contractions statiques et au cours de la marche. La première étude compare la modulation de l’activité réflexe du soléaire suite à la stimulation du nerf fémoral entre des sujets hémiparétiques et sains. Une augmentation de la facilitation hétéronyme de courte latence et une diminution de l’inhibition ultérieure du réflexe H du soléaire ont été observées chez les sujets hémiparétiques. Ces résultats démontrent un dysfonctionnement des circuits intersegmentaires propriospinaux liant le quadriceps au soléaire suite à l’AVC. La deuxième étude démontre que ces changements dans la modulation hétéronyme des sujets hémiparétiques, évaluée au moyen de la méthode complexe basée sur l’activité réflexe du soléaire, sont similaires à ceux observés lorsque la modulation est évaluée en utilisant une méthode plus simple, soit celle de l’activité volontaire du soléaire. De plus, la modulation hétéronyme évaluée par les deux méthodes est corrélée avec l’atteinte motrice à la jambe parétique. La troisième étude a permis de quantifier une augmentation de la coactivation entre les extenseurs du genou et de la cheville lors de contractions volontaires statiques chez des personnes hémiparétiques par rapport à des personnes saines. De plus, le niveau accru de la coactivation involontaire des extenseurs de la cheville lors de l’activation volontaire des extenseurs du genou s’avère corrélé avec la modulation intersegmentaire du côté parétique. La quatrième étude a utilisé un indice temporel, soit l’intervalle entre les pics d’activation électromyographique (PAI), et un indice d’amplitude de coactivation (CAI) pour quantifier une augmentation de la coactivation entre les extenseurs du genou et de la cheville lors de la marche chez des personnes hémiparétiques par rapport à des personnes saines. Ces indices sont corrélés, pour certains groupes musculaires, avec la modulation intersegmentaire modifiée du côté parétique. Finalement, des résultats préliminaires montrent que la vibration mécanique du tendon rotulien (80 Hz) réduit la facilitation intersegmentaire accrue des sujets hémiparétiques. Ce projet doctoral a permis de mettre en lumière un dysfonctionnement de circuits spinaux liant le quadriceps et le soléaire dans l’hémiparésie consécutive à un AVC. Ce changement dans les mécanismes neurophysiologiques de la moelle épinière est corrélé avec des changements fonctionnels. Ainsi, ce dysfonctionnement pourrait contribuer à la coactivation involontaire entre les extenseurs du genou et de la cheville qui fait partie intégrante de la synergie pathologique en extension souvent rencontrée à la jambe parétique lors d’efforts en statique et pendant la marche. Finalement, une étude préliminaire suggère que la vibration mécanique serait une modalité sensorielle prometteuse pour réguler l’hyperexcitabilité des circuits spinaux qui contribuerait aux atteintes motrices chez les personnes hémiparétiques.

Electronic structure and optical properties of BaMoO(4) powders

Barium molybdate (BaMoO(4)) powders were synthesized by the co-precipitation method and processed in microwave-hydrothermal at 140 degrees C for different times. These powders were characterized by X-ray diffraction (XRD), Fourier transform Raman (FT-Raman), Fourier transform infrared (FT-IR), ultraviolet-visible (UV-vis) absorption spectroscopies and photoluminescence (PL) measurements. XRD patterns and FT-Raman spectra showed that these powders present a scheelite-type tetragonal structure without the presence of deleterious phases. FT-IR spectra exhibited a large absorption band situated at around 850.4 cm(-1), which is associated to the Mo-O antisymmetric stretching vibrations into the [MoO(4)] clusters. UV-vis absorption spectra indicated a reduction in the intermediary energy levels within band gap with the processing time evolution. First-principles quantum mechanical calculations based on the density functional theory were employed in order to understand the electronic structure (band structure and density of states) of this material. The powders when excited with different wavelengths (350 nm and 488 nm) presented variations. This phenomenon was explained through a model based in the presence of intermediary energy levels (deep and shallow holes) within the band gap. (C) 2009 Elsevier B.V. All rights reserved.

Síntese de pigmento cerâmico ferrita de cobalto utilizando planejamento experimental

Synthetic inorganic pigments are the most widely used in ceramic applications because they have excellent chemical and thermal stability and also, in general, a lower toxicity to man and to the environment. In the present work, the ceramic black pigment CoFe2O4 was synthesized by the polymerization Complex method (MPC) in order to form a material with good chemical homogeneity. Aiming to optimize the process of getting the pigment through the MPC was used a fractional factorial design 2(5-2), with resolution III. The factors studied in mathematical models were: citric acid concentration, the pyrolysis time, temperature, time and rate of calcination. The response surfaces using the software statistica 7.0. The powders were characterized by thermal analysis (TG/DSC), x-ray diffraction (XRD), scanning electron microscopy (SEM) and spectroscopy in the UV-visible. Based on the results, there was the formation of phase cobalt ferrite (CoFe2O4) with spinel structure. The color of the pigments obtained showed dark shades, from black to gray. The model chosen was appropriate since proved to be adjusted and predictive. Planning also showed that all factors were significant, with a confidence level of 95%

Characterizing subpopulations of neoplastic cells in serous effusions - the role of immunocytochemistry

OBJECTIVE: To analyze the role of immunochemistry in serous effusions.STUDY DESIGN: We analyzed cell blocks of 18 pleural and 18 peritoneal effusions diagnosed as malignant (18), benign (14) and suspicious (4). They were immunostained by the avidin-biotin complex method with a panel of four monoclonal antibodies-CEA, Ber-EP4, LeuM1 (CD15) and r53-and for lectins (Ulex europaeus) UEA-1, ConA and ConBr. RESULTS: Seventeen of the 18 cases of adenocarcinoma were positive for CEA (95%), 12 (66.6%)for Bev-EP4, 11 (61 %)for CD15 nild 11 (62 %)for p53. Twelve of the 18 (66.6%) were positive for UEA-1, CEA, Ber-EP4 and CD15. UEA-1 did not react with mesothelial cells. p53 Gave a positive reaction in only one case, reactive mesothelial cells. ConA and ConBr reacted indiscriminately with benign and malignant cells; thus, it was not useful in distinguishing between these cells.CONCLUSION: In this context no antibody used alone is reliable for corroborating a diagnosis, but the selective use of a small panel of three markers (CEA, Ber-EP4 and LeuM1) can be very useful in solving diagnostic difficulties in the cytodiagnosis of serous effusions.

Expression of betacatenin in carcinoma in pleomorphic adenoma, pleomorphic adenoma and normal salivary gland: an immunohistochemical study

OBJECTIVES: Pleomorphic adenomas are the most frequent type of epithelial salivary gland neoplasms, and their malignant counterpart, the carcinoma in pleomorphic adenomas, is much less common. Beta-catenin is a cell adhesion molecule associated with the invasion and metastasis of carcinomas of the head and neck, esophagus. The objective of this study was to detect the expression of beta-catenin in pleomorphic adenomas, carcinomas in pleomorphic adenomas and normal salivary glands to discuss its role in the development of these two lesions. STUDY DESIGN: The expression of beta-catenin (BD Transduction Laboratories) was analyzed by immunohistochemistry in formalin-fixed, paraffin embedded specimens by the avidin-biotin-peroxidase complex method in 16 pleomorphic adenomas (12 from minor salivary glands), 3 carcinomas in pleomorphic adenomas (all from palate) and 10 normal salivary glands as control group (5 from major and 5 from minor salivary glands). RESULTS: All cases of glands, adenomas and carcinomas in pleomorphic adenomas have membranous and cytoplasmic immunostaining. Nuclear beta-catenin immunostaining was not observed. The antibody presented a fine granular arrangement in the cytoplasm and cellular membrane of duct and acinic cells. Higher beta-catenin index rates were seen mainly in salivary gland ducts and in ductal structures in the adenomas and carcinomas in pleomorphic adenomas. There was protein loss in pleomorphic adenomas and cytoplasmic accumulation in carcinoma in pleomorphic adenomas. CONCLUSIONS: The present study showed participation of the loss of beta-catenin adhesion molecule in the development of pleomorphic adenoma, and that the cytoplasmic accumulation of the molecule takes part in the malignant transformation of the pleomorphic adenoma into carcinoma in pleomorphic adenoma.

From polymer precursors to metal oxides

We report on a strategy to prepare metal oxides including binary oxide and mixed metal oxide (MMO) in form of nanometer-sized particles using polymer as precursor. Zinc oxide nanoparticles are prepared as an example. The obtained zinc polyacrylate precursor is amorphous as confirmed by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The conversion from polymer precursor to ZnO nanocrystals by thermal pyrolysis was investigated by means of XRD, thermogravimetric analysis (TGA) and electron microscopy. The as-synthesized ZnO consists of many individual particles with a diameter around 40 nm as shown by scanning electron microscopy (SEM). The photoluminescence (PL) and electron paramagnetic (EPR) properties of the material are investigated, too. Employing this method, ZnO nanocrystalline films are fabricated via pyrolysis of a zinc polyacrylate precursor film on solid substrate like silicon and quartz glass. The results of XRD, absorption spectra as well as TEM prove that both the ZnO nanopowder and film undergo same evolution process. Comparing the PL properties of films fabricated in different gas atmosphere, it is assigned that the blue emission of the ZnO films is due to crystal defect of zinc vacancy and green emission from oxygen vacancy. Two kinds of ZnO-based mixed metal oxide (Zn1-xMgxO and Zn1-xCoxO) particles with very precise stoichiometry are prepared by controlled pyrolysis of the corresponding polymer precursor at 550 oC. The MMO crystal particles are typically 20-50 nm in diameter. Doping of Mg in ZnO lattice causes shrinkage of lattice parameter c, while it remains unchanged with Co incorporation. Effects of bandgap engineering are seen in the Mg:ZnO system. The photoluminescence in the visible is enhanced by incorporation of magnesium on zinc lattice sites, while the emission is suppressed in the Co:ZnO system. Magnetic property of cobalt doped-ZnO is checked too and ferromagnetic ordering was not found in our samples. An alternative way to prepare zinc oxide nanoparticles is presented upon calcination of zinc-loaded polymer precursors, which is synthesized via inverse miniemulsion polymerization of the mixture of the acrylic acid and zinc nitrate. The as-prepared ZnO product is compared with that obtained from polymer-salt complex method. The obtained ZnO nanoparticles undergo surface modification via a phosphate modifier applying ultrasonication. The morphology of the modified particles is checked by SEM. And stability of the ZnO nanoparticles in aqueous dispersion is enhanced as indicated by the zeta-potential results.

The Estimation of the Ecological Condition of the City Environment by Methods of Phytoindication (as Applied to the Vasileostrovsky District of St. Petersburg)

The project aimed to use results of contamination of city vegetation with heavy metals and sulphur compounds as the basis for analysing the integral response of trees and shrubs to contamination, through a complex method of phytoindication. The results were used to draw up recommendations on pollution reduction in the city and to develop the method of phytoindication as a means of monitoring environmental pollution in St. Petersburg and other large cities. Field investigations were carried out in August 1996, and 66 descriptions of green areas were made in order to estimate the functional state of plants in the Vasileostrovsky district. Investigations of the spectrum reflecting properties of plants showed considerable variation of albedo meanings of leaves under the influence of various internal and external factors. The results indicated that lime trees most closely reflect the condition of the environment. Practically all the green areas studied were in poor condition, the only exceptions being areas of ash trees, which are more resistant to environmental pollution, and one lime-tree alley in a comparatively unpolluted street. The study identified those types of trees which are more or less resistant to complex environmental pollution and Ms. Terekhina recommends that the species in the present green areas be changed to include a higher number of the more resistant species. The turbidimetric analysis of tree barks for sulphates gave an indication of the level and spatial distribution of each pollutant, and the results also confirmed other findings that electric conductivity is a significant feature in determining the extent of sulphate pollution. In testing for various metals, the lime tree showed the highest contents for all elements except magnesium, copper, zinc, cadmium and strontium, again confirming the species' vulnerability to pollution. Medium rates of concentration in the city and environs showed that city plants concentrate 3 times as many different elements and 10 times more chromium, copper and lead than do those in the suburbs. The second stage of the study was based on the concept of phytoindication, which presupposes that changes in the relation of chemical elements in regional biological circulation under the influence of technogenesis provide a criterion for predicting displacements in people's health. There are certain basic factors in this concept. The first is that all living beings are related ecologically as well as by their evolutionary origin, and that the lower an organism is on the evolutionary scale, the less adaptational reserve it has. The second is that smaller concentrations of chemical elements are needed for toxicological influence on plants than on people and so the former's reactions to geochemical factors are easier to characterise. Visual indicational features of urban plants are well defined and can form the basis of a complex "environment - public health" analysis. Specific plant reactions reflecting atmospheric pollution and other components of urbogeosystems make it possible to determine indication criteria for predicting possible disturbances in the general state of health of the population. Thirdly the results of phytoindication investigations must be taken together with information about public health in the area. It only proved possibly to analyse general indexes of public health based on statistical data from the late 1980s and early 1990s as the data of later years were greatly influenced by social factors. These data show that the rates of illness in St. Petersburg (especially for children) are higher than in Russia as a whole, for most classes of diseases, indicating that the population there is more sensitive to the ecological state of the urban environment. The Vasileostrovsky district had the second highest sick rate for adullts, while the rate of infant mortality in the first year of life was highest there. Ms. Terekhina recommends further studies to more precisely assess the effectiveness of the methods she tested, but has drawn up a proposed map of environmental hazard for the population, taking into account prevailing wind directions.

Electron energy-loss spectroscopy as a tool for elemental analysis in biological speciments.

A transmission electron microscope (TEM) accessory, the energy filter, enables the establishment of a method for elemental microanalysis, the electron energy-loss spectroscopy (EELS). In conventional TEM, unscattered, elastic, and inelastic scattered electrons contribute to image information. Energy-filtering TEM (EFTEM) allows elemental analysis at the ultrastructural level by using selected inelastic scattered electrons. EELS is an excellent method for elemental microanalysis and nanoanalysis with good sensitivity and accuracy. However, it is a complex method whose potential is seldom completely exploited, especially for biological specimens. In addition to spectral analysis, parallel-EELS, we present two different imaging techniques in this chapter, namely electron spectroscopic imaging (ESI) and image-EELS. We aim to introduce these techniques in this chapter with the elemental microanalysis of titanium. Ultrafine, 22-nm titanium dioxide particles are used in an inhalation study in rats to investigate the distribution of nanoparticles in lung tissue.

Estimation of sex and age of "virtual skeletons"--a feasibility study

This article presents a feasibility study with the objective of investigating the potential of multi-detector computed tomography (MDCT) to estimate the bone age and sex of deceased persons. To obtain virtual skeletons, the bodies of 22 deceased persons with known age at death were scanned by MDCT using a special protocol that consisted of high-resolution imaging of the skull, shoulder girdle (including the upper half of the humeri), the symphysis pubis and the upper halves of the femora. Bone and soft-tissue reconstructions were performed in two and three dimensions. The resulting data were investigated by three anthropologists with different professional experience. Sex was determined by investigating three-dimensional models of the skull and pelvis. As a basic orientation for the age estimation, the complex method according to Nemeskéri and co-workers was applied. The final estimation was effected using additional parameters like the state of dentition, degeneration of the spine, etc., which where chosen individually by the three observers according to their experience. The results of the study show that the estimation of sex and age is possible by the use of MDCT. Virtual skeletons present an ideal collection for anthropological studies, because they are obtained in a non-invasive way and can be investigated ad infinitum.