991 resultados para Therapeutic application
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The aim of this study was to estimate barite mortar attenuation curves using X-ray spectra weighted by a workload distribution. A semi-empirical model was used for the evaluation of transmission properties of this material. Since ambient dose equivalent, H(⁎)(10), is the radiation quantity adopted by IAEA for dose assessment, the variation of the H(⁎)(10) as a function of barite mortar thickness was calculated using primary experimental spectra. A CdTe detector was used for the measurement of these spectra. The resulting spectra were adopted for estimating the optimized thickness of protective barrier needed for shielding an area in an X-ray imaging facility.
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To verify the methods used by the clinical trials that assessed the effect of tactile/kinesthetic stimulation on weight gain in preterm infants and highlight the similarities and differences among such studies. This review collected studies from two databases, PEDro and PubMed, in July of 2014, in addition to bibliographies. Two researchers assessed the relevant titles independently, and then chose which studies to read in full and include in this review by consensus. Clinical trials that studied tactile stimulation or massage therapy whether or not associated with kinesthetic stimulation of preterm infants; that assessed weight gain after the intervention; that had a control group and were composed in English, Portuguese, or Spanish were included. A total of 520 titles were found and 108 were selected for manuscript reading. Repeated studies were excluded, resulting in 40 different studies. Of these, 31 met all the inclusion criteria. There were many differences in the application of tactile/kinesthetic stimulation techniques among studies, which hindered the accurate reproduction of the procedure. Also, many studies did not describe the adverse events that occurred during stimulation, the course of action taken when such events occurred, and their effect on the outcome. These studies made a relevant contribution towards indicating tactile/kinesthetic stimulation as a promising tool. Nevertheless, there was no standard for application among them. Future studies should raise the level of methodological rigor and describe the adverse events. This may permit other researchers to be more aware of expected outcomes, and a standard technique could be established.
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Mapping of elements in biological tissue by laser induced mass spectrometry is a fast growing analytical methodology in life sciences. This method provides a multitude of useful information of metal, nonmetal, metalloid and isotopic distribution at major, minor and trace concentration ranges, usually with a lateral resolution of 12-160 µm. Selected applications in medical research require an improved lateral resolution of laser induced mass spectrometric technique at the low micrometre scale and below. The present work demonstrates the applicability of a recently developed analytical methodology - laser microdissection associated to inductively coupled plasma mass spectrometry (LMD ICP-MS) - to obtain elemental images of different solid biological samples at high lateral resolution. LMD ICP-MS images of mouse brain tissue samples stained with uranium and native are shown, and a direct comparison of LMD and laser ablation (LA) ICP-MS imaging methodologies, in terms of elemental quantification, is performed.
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Efforts presented by the scientific community in recent years towards the development of numerous green chemical processes and wastewater treatment technologies are presented and discussed. In the light of these approaches, environmentally friendly technologies, as well as the key role played by the well-known advanced oxidation processes, are discussed, giving special attention to the ones comprising ozone applications. Fundamentals and applied aspects dealing with ozone technology and its application are also presented.
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Universidade Estadual de Campinas . Faculdade de Educação Física
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Universidade Estadual de Campinas . Faculdade de Educação Física
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The South American fur seal (Arctocephalus australis) is an amphibious marine mammal distributed along the Atlantic and Pacific coasts of South America. The species is well adjusted to different habitats due to the morphology of its fin-like members and due to some adaptations in their integumentary system. Immunohistochemical studies are very important to evaluate the mechanisms of skin adaptation due the differential expression of the antigens present in the tissue depending of the region of the body surface. However, its strongly pigmented (melanin) epidermis prevents the visualization of the immuno-histochemical chromogens markers. In this study a melanin bleaching method was developed aimed to allow the visualization of the chromogens without interfering in the antigen-antibody affinity for immunohistochemistry. The analysis of PCNA (proliferating cell nuclear antigen) index in the epidermis of A. australis by immunohistochemistry with diaminobenzidine (DAB) as chromogen was used to test the method. The bleaching of the melanin allowed to obtain the cell proliferation index in epidermis and to avoid false positive results without affecting the immunohistochemical results.
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A simple and low cost method to determine volatile contaminants in post-consumer recycled PET flakes was developed and validated by Headspace Dynamic Concentration and Gas Chromatography-Flame Ionization Detection (HDC-GC-FID). The analytical parameters evaluated by using surrogates include: correlation coefficient, detection limit, quantification limit, accuracy, intra-assay precision, and inter-assay precision. In order to compare the efficiency of the proposed method to recognized automated techniques, post-consumer PET packaging samples collected in Brazil were used. GC-MS was used to confirm the identity of the substances identified in the PET packaging. Some of the identified contaminants were estimated in the post-consumer material at concentrations higher than 220 ng.g-1. The findings in this work corroborate data available in the scientific literature pointing out the suitability of the proposed analytical method.
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Cross-amplification was tested and variability in microsatellite primers (designed for Neotropical parrots) compared, in five macaw species, viz., three endangered blue macaws (Cyanopsitta spixii [extinct in the wild], Anodorhynchus leari [endangered] and Anodorhynchus hyacinthinus [vulnerable]), and two unthreatened red macaws (Ara chloropterus and Ara macao). Among the primers tested, 84.6% successfully amplified products in C. spixii, 83.3% in A. leari, 76.4% in A. hyacinthinus, 78.6% in A. chloropterus and 71.4% in A. macao. The mean expected heterozygosity estimated for each species, and based on loci analyzed in all the five, ranged from 0.33 (A. hyacinthinus) to 0.85 (A. macao). As expected, the results revealed lower levels of genetic variability in threatened macaw species than in unthreatened. The low combined probability of genetic identity and the moderate to high potential for paternity exclusion, indicate the utility of the microsatellite loci set selected for each macaw species in kinship and population studies, thus constituting an aid in planning in-situ and ex-situ conservation.
Effect of therapeutic dose X rays on mechanical and chemical properties of esthetic dental materials
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The aim of this study was to investigate the influence of therapeutic dose X rays on the microhardness (MH) and degree of conversion (DC) of two different esthetic restorative dental materials. The materials were photo-activated with a LED light-curing unit using three cure-times: 5, 20 and 40 seconds. The photo-activation was carried out in two distinct periods: before and after irradiation with doses of 5, 35 and 70 Gy, from a 6 MV X rays beam. In accordance with the methodology used, it was conclude that a therapeutic dose does not have a detrimental effect on the photoinitiator molecules, because the photo-activation occurred after they were irradiated. When the irradiation was applied before photo-activation, the materials showed MH improvement, but when photo-activation was performed after irradiation, there was less improvement. However, there was no correlation between MH and DC. Thus, a therapeutic dose applied to cured material can promote linking and breaking of chain bonds in a non-linear way.
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Therapeutic failure of benznidazole (BZ) is widely documented in Chagas disease and has been primarily associated with variations in the drug susceptibility of Trypanosoma cruzi strains. In humans, therapeutic success has been assessed by the negativation of anti-T. cruzi antibodies, a process that may take up to 10 years. A protocol for early screening of the drug resistance of infective strains would be valuable for orienting physicians towards alternative therapies, with a combination of existing drugs or new anti-T. cruzi agents. We developed a procedure that couples the isolation of parasites by haemoculture with quantification of BZ susceptibility in the resultant epimastigote forms. BZ activity was standardized with reference strains, which showed IC50 to BZ between 7.6-32 µM. The assay was then applied to isolates from seven chronic patients prior to administration of BZ therapy. The IC50 of the strains varied from 15.6 ± 3-51.4 ± 1 µM. Comparison of BZ susceptibility of the pre-treatment isolates of patients considered cured by several criteria and of non-cured patients indicates that the assay does not predict therapeutic outcome. A two-fold increase in BZ resistance in the post-treatment isolates of two patients was verified. Based on the profile of nine microsatellite loci, sub-population selection in non-cured patients was ruled out.
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Studies about the inorganic nanoparticles applying for non-viral release of biological and therapeutic species have been intensified nowadays. This work reviews the preparation strategies and application of layered double hydroxides (LDH) as carriers for storing, carrying and control delivery of intercalated species as drugs and DNA for gene therapy. LDH show low toxicity, biocompatibility, high anion exchange capacity, surface sites for functionalization, and a suitable equilibrium between chemical stability and biodegradability. LDH can increase the intercalated species stability and promote its sub-cellular uptake for biomedical purposes. Concerning the healthy field, LDH have been evaluated for clinical diagnosis as a biosensor component.
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The aim of this study was to optimize a PCR assay that amplifies an 843 pb fragment from the p28 gene of Ehrlichia canis and compare it with two other PCR methods used to amplify portions of the 16S rRNA and dsb genes of Ehrlichia. Blood samples were collected from dogs suspected of having a positive diagnosis for canine ehrlichiosis. Amplification of the p28 gene by PCR produced an 843-bp fragment and this assay could detect DNA from one gene copy among 1 billion cells. All positive samples detected by the p28-based PCR were also positive by the 16S rRNA nested-PCR and also by the dsb-based PCR. Among the p28-based PCR negative samples, 55.3% were co-negatives, but 27.6% were positive in 16S rRNA and dsb based PCR assays. The p28-based PCR seems to be a useful test for the molecular detection of E. canis, however improvements in this PCR sensitivity are desired, so that it can become an important alternative in the diagnosis of canine ehrlichiosis.
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Three welding procedures used to rebuild worn shafts in sugar cane mills were analysed: two submerged arc welding processes and one flux cored arc welding (FCAW) process. Sliding wear tests were in accordance with ASTM G 77 standard, using rings of welding material, blocks of bronze SAE 67, and oil as lubricant. The worn surfaces of rings and blocks were analysed by scanning electron microscopy to determine the wear mechanisms. High contact pressure, high operating temperature, and low relative speed were applied in sliding wear tests to match the conditions in sugar cane mills. Transferred material and evidence of adhesive junctions were detected. Additionally, hardened fragments produced abrasive grooves on the worn surfaces. The welding deposits that presented strong adhesion on the worn surface showed higher mass loss than the materials that presented more abrasive characteristics. Plastic mechanical properties were measured and related to the mass loss. The tested materials presented similar hardness but different yield stress and hardening coefficient. A relationship between wear, strain hardening coefficient, and yield stress was found. The welding deposit that presented the highest hardening coefficient showed the highest mass loss, with evidence of severe adhesion on the worn surface.
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Background: Leukotriene B(4) (LTB(4)) is a potent inflammatory mediator that also stimulates the immune response. In addition, it promotes polymorphonuclear leukocyte phagocytosis, chemotaxis, chemokinesis and modulates cytokines release. Regarding chemical instability of the leukotriene molecule, in the present study we assessed the immunomodulatory activities conferred by LTB(4) released from microspheres (MS). A previous oil-in-water emulsion solvent extraction-evaporation method was chosen to prepare LTB(4)-loaded MS. Results: In the mice cremasteric microcirculation, intraescrotal injection of 0.1 ml of LTB(4)-loaded MS provoked significant increases in leukocyte rolling flux, adhesion and emigration besides significant decreases in the leukocyte rolling velocity. LTB(4)-loaded MS also increase peroxisome proliferator-activated receptor-alpha (PPAR alpha) expression by murine peritoneal macrophages and stimulate them to generate nitrite levels. Monocyte chemoattractant protein-I (MCP-I) and nitric oxide (NO) productions were also increased when human umbilical vein and artery endothelial cells (HUVECs and HUAECs, respectively) were stimulated with LTB(4)-loaded MS. Conclusion: LTB(4)-loaded MS preserve the biological activity of the encapsulated mediator indicating their use as a new strategy to modulate cell activation, especially in the innate immune response.