NMR in Crystals and Powders of Topazes with Different Colours

The present work is a part of the large project with purpose to investigate microstructure and electronic structure of natural topazes using NMR method. To reach this task we determined the relative contents of fluorine and hydrogen in crystals blue, colorless, wine and wine irradiated topazes. Then we determined the electric field gradients in site of aluminium atoms by NMR method, calculated EFG using ab initio method, and measured relaxation time dependence on heating temperature for blue, colorless, Swiss blue and sky blue topazes. Nuclear magnetic resonance (NMR) is an effective method to investigate the local structure in the crystal. The NMR study of the single crystal gives detailed information especially about the local crystal structure. As a result of this work we have received practical data, which is possible to use in future for making personal dosimetry and for preparation of mullite, which is widely used in traditional and advanced ceramic materials.

Language recovery and evidence of residual deficits after nonthalamic subcortical stroke: A 1 year follow-up study

A variety of language disturbances including aphasia have been described after subcortical stroke but less is known about the factors that influence the long-term recovery of stroke-induced language dysfunction. We prospectively examined the role of the affected hemisphere and the lesion site in the occurrence and recovery of language deficits in nonthalamic subcortical stroke. Forty patients with unilateral basal gangliastroke underwent language assessment within 1 week, 3 months and 1 year after stroke. Disturbances in at least one language domain were observed in 35 patients during the first week post stroke including aphasia diagnosed in 11 patients. Importantly, the appearance of deficits after stroke onset and the improvement of language function were not determined by the site of subcortical lesion, but instead were critically influenced by the affected hemisphere. In fact, the language impairments following left and right basal ganglia stroke mirrored the language dysfunction observed after cortical lesions in the same hemisphere. A significant overall language improvement was observed at 3 months after stroke, although residual deficits in languageexecutive function were the most commonly observed impairment at 1 year follow-up. Although a substantial improvement of language function can be expected after nonthalamic subcortical stroke, our findings suggest that language recovery may not be fully achieved at 1 year post

Early Detection of Alzheimer's Disease Beta-amyloid Pathology -Applicability of Positron Emission Tomography with the Amyloid Radioligand 11C-PIB

Early Detection of Alzheimer's Disease Beta-amyloid Pathology -Applicability of Positron Emission Tomography with the Amyloid Radioligand ¹¹C-PIB Accumulation of beta amyloid (Abeta) in the brain is characteristic for Alzheimer’s disease (AD). Carbon-11 labeled 2-(4’-methylaminophenyl)-6-hydroxybenzothiazole (¹¹C-PIB) is a novel positron emission tomography (PET) amyloid imaging agent that appears to be applicable for in vivo Abeta plaque detection and quantitation. The biodistribution and radiation dosimetry of ¹¹C-PIB were investigated in 16 healthy subjects. The reproducibility of a simplified ¹¹C-PIB quantitation method was evaluated with a test-retest study on 6 AD patients and 4 healthy control subjects. Brain ¹¹C-PIB uptake and its possible association with brain atrophy rates were studied over a two-year follow-up in 14 AD patients and 13 healthy controls. Nine monozygotic and 8 dizygotic twin pairs discordant for cognitive impairment and 9 unrelated controls were examined to determine whether brain Abeta accumulation could be detected with ¹¹C-PIB PET in cognitively intact persons who are at increased genetic risk for AD. The highest absorbed radiation dose was received by the gallbladder wall (41.5 mjuGy/MBq). About 20 % of the injected radioactivity was excreted into urine, and the effective whole-body radiation dose was 4.7 mjuSv/MBq. Such a dose allows repeated scans of individual subjects. The reproducibility of the simplified ¹¹C-PIB quantitation was good or excellent both at the regional level (VAR 0.9-5.5 %) and at the voxel level (VAR 4.2-6.4 %). ¹¹C-PIB uptake did not increase during 24 months’ follow-up of subjects with mild or moderate AD, even though brain atrophy and cognitive decline progressed. Baseline neocortical ¹¹C-PIB uptake predicted subsequent volumetric brain changes in healthy control subjects (r = 0.725, p = 0.005). Cognitively intact monozygotic co-twins – but not dizygotic co-twins – of memory-impaired subjects exhibited increased ¹¹C-PIB uptake (117-121 % of control mean) in their temporal and parietal cortices and the posterior cingulate (p<0.05), when compared with unrelated controls. This increased uptake may be representative of an early AD process, and genetic factors seem to play an important role in the development of AD-like Abeta plaque pathology. ¹¹C-PIB PET may be a useful method for patient selection and follow-up for early-phase intervention trials of novel therapeutic agents. AD might be detectable in high-risk individuals in its presymptomatic stage with ¹¹C-PIB PET, which would have important consequences both for future diagnostics and for research on disease-modifying treatments.

Adsorption of hidrogen peroxide on the surface of silica - titania mixed oxide obtained by the sol-gel processing method

This work describes the sol-gel mixed oxide SiO2/TiO2 property, ST, as prepared, and submitted to heat treatment a 773 K, STC. SEM and EDS images show, within magnification used, a uniform distribution of the TiO2 particles in SiO2/TiO2 matrix. Both, ST and STC adsorb hydrogen peroxide on the surface and through EPR and UV-Vis diffuse reflectance spectra, it was possible to conclude that the species on the surface is the peroxide molecule attached to the Lewis acid site of titanium particle surface, alphaTi(H2O2)+. As the material is very porous, presumably the hydrogen peroxide molecule is confined in the matrix pores on the surface, a reason why the adsorbed species presents an exceptional long lived stability.

Memory as acquaintance with the past: some Lessons from Russell, 1912-1914

Russell's theory of memory as acquaintance with the past seems to square uneasily with his definition of acquaintance as the converse of the relation of presentation of an object to a subject. We show how the two views can be made to cohere under a suitable construal of 'presentation', which has the additional appeal of bringing Russell's theory of memory closer to contemporary views on direct reference and object-dependent thinking than is usually acknowledged. The drawback is that memory as acquaintance with the past falls short of fulfilling Russell's requirement that knowledge by acquaintance be discriminating knowledge - a shortcoming shared by contemporary externalist accounts of knowledge from memory.

In vivo imaging of vascular adhesion protein 1 - preclinical studies with positron emission tomography

The golden standard in nuclear medicine imaging of inflammation is the use of radiolabeled leukocytes. Although their diagnostic accuracy is good, the preparation of the leukocytes is both laborious and potentially hazardous for laboratory personnel. Molecules involved in leukocyte migration could serve as targets for the development of inflammation imaging agents. An excellent target would be a molecule that is absent or expressed at low level in normal tissues, but is induced or up-regulated at the site of inflammation. Vascular adhesion protein-1 (VAP-1) is a very promising target for in vivo imaging, since it is translocated to the endothelial cell surface when inflammation occurs. VAP-1 functions as an endothelial adhesion molecule that participates in leukocyte recruitment to inflamed tissues. Besides being an adhesion molecule, VAP-1 also has enzymatic activity. In this thesis, the targeting of VAP-1 was studied by using Gallium-68 (68Ga) labeled peptides and an Iodine-124 (124I) labeled antibody. The peptides were designed based on molecular modelling and phage display library searches. The new imaging agents were preclinically tested in vitro, as well as in vivo in animal models. The most promising imaging agent appeared to be a peptide belonging to the VAP-1 leukocyte ligand, Siglec-9 peptide. The 68Ga-labeled Siglec-9 peptide was able to detect VAP-1 positive vasculature in rodent models of sterile skin inflammation and melanoma by positron emission tomography. In addition to peptides, the 124I-labeled antibody showed VAP-1 specific binding both in vitro and in vivo. However, the estimated human radiation dose was rather high, and thus further preclinical studies in disease models are needed to clarify the value of this imaging agent. Detection of VAP-1 on endothelium was demonstrated in these studies and this imaging approach could be used in the diagnosis of inflammatory conditions as well as melanoma. These studies provide a proof-of-concept for PET imaging of VAP-1 and further studies are warranted.

Critical analysis of thoracotomies performed in the emergency room in 10 years

OBJECTIVE: To conduct a critical analysis of thoracotomies performed in the emergency rooms.METHODS: We analyzed mortality rates and survival as outcome variables, mechanism of injury, site of injury and anatomic injury as clinical variables, and gender and age as demographic variables of patients undergoing thoracotomy in the emergency room after traumatic injury.RESULTS: Of the 105 patients, 89.5% were male. The average age was 29.2 years. Penetrating trauma accounted for 81% of cases. The most common mechanism of trauma was wound by a firearm projectile (gunshot), in 64.7% of cases. Patients with stab wounds (SW) accounted for 16.2% of cases. Overall survival was 4.7%. Survival by gunshot was 1.4%, and by SW, 23.5%. The ERT following blunt trauma showed a 100%mortality.CONCLUSION: The results obtained in the Emergency Hospital of Porto Alegre POA-HPS are similar to those reported in the world literature.

Production of Mg(OH)2 from Mg-silicate rock for CO2 mineral sequestration

Sequestration of carbon dioxide in mineral rocks, also known as CO2 Capture and Mineralization (CCM), is considered to have a huge potential in stabilizing anthropogenic CO2 emissions. One of the CCM routes is the ex situ indirect gas/sold carbonation of reactive materials, such as Mg(OH)2, produced from abundantly available Mg-silicate rocks. The gas/solid carbonation method is intensively researched at Åbo Akademi University (ÅAU ), Finland because it is energetically attractive and utilizes the exothermic chemistry of Mg(OH)2 carbonation. In this thesis, a method for producing Mg(OH)2 from Mg-silicate rocks for CCM was investigated, and the process efficiency, energy and environmental impact assessed. The Mg(OH)2 process studied here was first proposed in 2008 in a Master’s Thesis by the author. At that time the process was applied to only one Mg-silicate rock (Finnish serpentinite from the Hitura nickel mine site of Finn Nickel) and the optimum process conversions, energy and environmental performance were not known. Producing Mg(OH)2 from Mg-silicate rocks involves a two-staged process of Mg extraction and Mg(OH)2 precipitation. The first stage extracts Mg and other cations by reacting pulverized serpentinite or olivine rocks with ammonium sulfate (AS) salt at 400 - 550 oC (preferably < 450 oC). In the second stage, ammonia solution reacts with the cations (extracted from the first stage after they are leached in water) to form mainly FeOOH, high purity Mg(OH)2 and aqueous (dissolved) AS. The Mg(OH)2 process described here is closed loop in nature; gaseous ammonia and water vapour are produced from the extraction stage, recovered and used as reagent for the precipitation stage. The AS reagent is thereafter recovered after the precipitation stage. The Mg extraction stage, being the conversion-determining and the most energy-intensive step of the entire CCM process chain, received a prominent attention in this study. The extraction behavior and reactivity of different rocks types (serpentinite and olivine rocks) from different locations worldwide (Australia, Finland, Lithuania, Norway and Portugal) was tested. Also, parametric evaluation was carried out to determine the optimal reaction temperature, time and chemical reagent (AS). Effects of reactor types and configuration, mixing and scale-up possibilities were also studied. The Mg(OH)2 produced can be used to convert CO2 to thermodynamically stable and environmentally benign magnesium carbonate. Therefore, the process energy and life cycle environmental performance of the ÅAU CCM technique that first produces Mg(OH)2 and the carbonates in a pressurized fluidized bed (FB) were assessed. The life cycle energy and environmental assessment approach applied in this thesis is motivated by the fact that the CCM technology should in itself offer a solution to what is both an energy and environmental problem. Results obtained in this study show that different Mg-silicate rocks react differently; olivine rocks being far less reactive than serpentinite rocks. In summary, the reactivity of Mg-silicate rocks is a function of both the chemical and physical properties of rocks. Reaction temperature and time remain important parameters to consider in process design and operation. Heat transfer properties of the reactor determine the temperature at which maximum Mg extraction is obtained. Also, an increase in reaction temperature leads to an increase in the extent of extraction, reaching a maximum yield at different temperatures depending on the reaction time. Process energy requirement for producing Mg(OH)2 from a hypothetical case of an iron-free serpentine rock is 3.62 GJ/t-CO2. This value can increase by 16 - 68% depending on the type of iron compound (FeO, Fe2O3 or Fe3O4) in the mineral. This suggests that the benefit from the potential use of FeOOH as an iron ore feedstock in iron and steelmaking should be determined by considering the energy, cost and emissions associated with the FeOOH by-product. AS recovery through crystallization is the second most energy intensive unit operation after the extraction reaction. However, the choice of mechanical vapor recompression (MVR) over the “simple evaporation” crystallization method has a potential energy savings of 15.2 GJ/t-CO2 (84 % savings). Integrating the Mg(OH)2 production method and the gas/solid carbonation process could provide up to an 25% energy offset to the CCM process energy requirements. Life cycle inventory assessment (LCIA) results show that for every ton of CO2 mineralized, the ÅAU CCM process avoids 430 - 480 kg CO2. The Mg(OH)2 process studied in this thesis has many promising features. Even at the current high energy and environmental burden, producing Mg(OH)2 from Mg-silicates can play a significant role in advancing CCM processes. However, dedicated future research and development (R&D) have potential to significantly improve the Mg(OH)2 process performance.

Adherence and experimental infection of bacteria associated with periodontal infections of young cattle in Brazil ("Cara inchada")

In vitro- and in vivo-assays were conducted, to study the possible role of streptomycin- and actinomycin-producing soil actinomycetes for the pathogenesis of "Cara inchada" in cattle (CI). Adherence of Bacteroides spp. to epithelial cells of the bovine gingiva, known to be associated with the progressive lesions of CI, was significantly increased by the addition of streptomycin, actinomycin or antibiotic culture supernatants of the soil actinomycetes. Applications of these mixtures together with Actinomyces pyogenes to the marginal gingiva of the upper premolar teeth of about 1 month old Holstein Friesian calves did not lead to progressive lesions of CI. Only one calf exhibited a slight diarrhea and a temporary retraction of the gingiva at the site of application.

Fifty years in the blink of an eye: a retrospective study of ocular and periocular lesions in domestic animals

A survey was undertaken aiming to obtain an overview of ocular and periocular lesions diagnosed in domestic mammals over a period of 50 years in a veterinary pathology diagnostic laboratory in the Central Region of the State of Rio Grande do Sul, Brazil. In this lab, 33,075 histophatological exams had been performed over the period surveyed, of which 540 (1.6%) concerned ocular and periocular lesions. For various reasons ninety specimens were excluded from the study and the remaining 450 consisted of samples from dogs (53.5%), cattle (28.2%), cats (11.1%), horses (5.1%) sheep (1.3%), rabbits (0.4%), and pig (0.2%). The eyelids were the most prevalent (248/450) site of lesions in each of the species studied, followed by third eyelid (73/450), and conjunctiva (27/450). In dogs (241 samples) lesions in sebaceous glands (including Meibomian glands) were the most common findings (75/241), followed by melanocytic tumors (52/241) and nonspecific conjunctivitis (13/241). Squamous cell neoplasms, both benign and malignant, were relatively common. In cattle, anatomical sites affected by ocular and periocular lesions, in decreasing order of frequency, were eyelid, cornea and third eyelid. Squamous cell carcinoma (SCC) alone accounted for 80.3% of all diagnoses, while all neoplastic lesions made up for 85.0% of the lesions diagnosed in cattle. Neoplasia accounted for most of the lesions diagnosed in cats (39/50 cases); all of these were malignant, and SCC, hemangiosarcoma and fibrosarcoma were the most common types diagnosed. In horses, 19 out of 23 submissions were neoplasms and most were sarcoid (8/23) and SCC (8/23). There were six submissions from sheep with unpigmented skin, all of which represented SCC of the eyelids (5) and third eyelid (1).

Cytokine gene expression and molecular detection of Mycobacterium avium subspecies paratuberculosisin organs of experimentally infected mice

AbstractMycobacterium avium subspecies paratuberculosis (MAP) can infect ruminants and remain subclinical for long periods within herds. The identification of organs that are more susceptible to infection and the evaluation of cytokine expression at the site of infection are important to understand the pathogenesis of MAP. In this study, the probability of detection of MAP-DNA and the expression of cytokines in organs of C57BL/6 mice infected intraperitoneally for 120 days were evaluated. Among the evaluated organs, the spleen (85%), colon (75%) and liver (60%) had the highest frequency of positivity. When compared these frequencies between organs, it has been found that the spleen had 1.54 times as likely to be positive in relation to the ileum, and 2.0 times more likely in relation to the Peyer's patches. In addition, at 60 days post-infection, the spleen and the liver were responsible for upregulation of IFN-γ , and the ileum by TNF-α and IL-4. The results indicate that the spleen is the best organ for evaluating an experimental infection by MAP, especially in the initial stages of the infection. Moreover, it showed that the spleen, liver and ileum have a direct role in the inflammatory response in experimental models.

Substitution-Newton-Raphson method applied to the modeling of a vapour compression refrigeration system using different representations of the thermodynamic properties of R-134a

This paper gives a detailed presentation of the Substitution-Newton-Raphson method, suitable for large sparse non-linear systems. It combines the Successive Substitution method and the Newton-Raphson method in such way as to take the best advantages of both, keeping the convergence features of the Newton-Raphson with the low requirements of memory and time of the Successive Substitution schemes. The large system is solved employing few effective variables, using the greatest possible part of the model equations in substitution fashion to fix the remaining variables, but maintaining the convergence characteristics of the Newton-Raphson. The methodology is exemplified through a simple algebraic system, and applied to a simple thermodynamic, mechanical and heat transfer modeling of a single-stage vapor compression refrigeration system. Three distinct approaches for reproducing the thermodynamic properties of the refrigerant R-134a are compared: the linear interpolation from tabulated data, the use of polynomial fitted curves and the use of functions derived from the Helmholtz free energy.

Methods of genetic diversity creation and functional display for directed evolution experiments

Protein engineering aims to improve the properties of enzymes and affinity reagents by genetic changes. Typical engineered properties are affinity, specificity, stability, expression, and solubility. Because proteins are complex biomolecules, the effects of specific genetic changes are seldom predictable. Consequently, a popular strategy in protein engineering is to create a library of genetic variants of the target molecule, and render the population in a selection process to sort the variants by the desired property. This technique, called directed evolution, is a central tool for trimming protein-based products used in a wide range of applications from laundry detergents to anti-cancer drugs. New methods are continuously needed to generate larger gene repertoires and compatible selection platforms to shorten the development timeline for new biochemicals. In the first study of this thesis, primer extension mutagenesis was revisited to establish higher quality gene variant libraries in Escherichia coli cells. In the second study, recombination was explored as a method to expand the number of screenable enzyme variants. A selection platform was developed to improve antigen binding fragment (Fab) display on filamentous phages in the third article and, in the fourth study, novel design concepts were tested by two differentially randomized recombinant antibody libraries. Finally, in the last study, the performance of the same antibody repertoire was compared in phage display selections as a genetic fusion to different phage capsid proteins and in different antibody formats, Fab vs. single chain variable fragment (ScFv), in order to find out the most suitable display platform for the library at hand. As a result of the studies, a novel gene library construction method, termed selective rolling circle amplification (sRCA), was developed. The method increases mutagenesis frequency close to 100% in the final library and the number of transformants over 100-fold compared to traditional primer extension mutagenesis. In the second study, Cre/loxP recombination was found to be an appropriate tool to resolve the DNA concatemer resulting from error-prone RCA (epRCA) mutagenesis into monomeric circular DNA units for higher efficiency transformation into E. coli. Library selections against antigens of various size in the fourth study demonstrated that diversity placed closer to the antigen binding site of antibodies supports generation of antibodies against haptens and peptides, whereas diversity at more peripheral locations is better suited for targeting proteins. The conclusion from a comparison of the display formats was that truncated capsid protein three (p3Δ) of filamentous phage was superior to the full-length p3 and protein nine (p9) in obtaining a high number of uniquely specific clones. Especially for digoxigenin, a difficult hapten target, the antibody repertoire as ScFv-p3Δ provided the clones with the highest affinity for binding. This thesis on the construction, design, and selection of gene variant libraries contributes to the practical know-how in directed evolution and contains useful information for scientists in the field to support their undertakings.

Intracellular and intercellular compartmentation of carbohydrate metabolism in leaves of temperate gramineae

This review considers the importance of compartmentation in the regulation of carbohydrate metabolism in leaves. We draw particular attention to the role of the vacuole as a site for storage of soluble sugars based on sucrose, and discuss briefly their characteristic metabolism. We also point out inconsistencies between the observed properties of vacuoles and the behaviour in vitro of the enzymes of fructan biosynthesis that do not support the hypothesis that the vacuole is the site of synthesis as well as of storage. We also consider compartmentation of carbohydrate metabolism between different cell types, using mainly our studies on leaves of temperate C3 gramineae. Here we present evidence of significant differences in carbon metabolism between epidermis, mesophyll, bundle sheath and vasculature based upon both single-cell sampling and immunolocalisation. The implications of these differences for the control of metabolism in leaves are discussed.

Influence of soil properties on the abundance of plant species in ferruginous rocky soils vegetation, southeastern Brazil

Ferruginous "campos rupestres" are a particular type of vegetation growing on iron-rich primary soils. We investigated the influence of soil properties on plant species abundance at two sites of ferruginous "campos rupestres" and one site of quartzitic "campo rupestre", all of them in "Quadrilátero Ferrífero", in Minas Gerais State, southeastern Brazil. In each site, 30 quadrats were sampled to assess plant species composition and abundance, and soil samples were taken to perform chemical and physical analyses. The analyzed soils are strongly acidic and presented low fertility and high levels of metallic cations; a principal component analysis of soil data showed a clear segregation among sites due mainly to fertility and heavy metals content, especially Cu, Zn, and Pb. The canonical correspondence analysis indicated a strong correlation between plant species abundance and soil properties, also segregating the sites.