53 resultados para Tópica


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Lithium (Li) is a chemical element with atomic number 3 and it is among the lightest known elements in the universe. In general, the Lithium is found in the nature under the form of two stable isotopes, the 6Li and 7Li. This last one is the most dominant and responds for about 93% of the Li found in the Universe. Due to its fragileness this element is largely used in the astrophysics, especially in what refers to the understanding of the physical process that has occurred since the Big Bang going through the evolution of the galaxies and stars. In the primordial nucleosynthesis in the Big Bang moment (BBN), the theoretical calculation forecasts a Li production along with all the light elements such as Deuterium and Beryllium. To the Li the BNB theory reviews a primordial abundance of Log log ǫ(Li) =2.72 dex in a logarithmic scale related to the H. The abundance of Li found on the poor metal stars, or pop II stars type, is called as being the abundance of Li primordial and is the measure as being log ǫ(Li) =2.27 dex. In the ISM (Interstellar medium), that reflects the current value, the abundance of Lithium is log ǫ(Li) = 3.2 dex. This value has great importance for our comprehension on the chemical evolution of the galaxy. The process responsible for the increasing of the primordial value present in the Li is not clearly understood until nowadays. In fact there is a real contribution of Li from the giant stars of little mass and this contribution needs to be well streamed if we want to understand our galaxy. The main objection in this logical sequence is the appearing of some giant stars with little mass of G and K spectral types which atmosphere is highly enriched with Li. Such elevated values are exactly the opposite of what could happen with the typical abundance of giant low mass stars, where convective envelops pass through a mass deepening in which all the Li should be diluted and present abundances around log ǫ(Li) ∼1.4 dex following the model of stellar evolution. In the Literature three suggestions are found that try to reconcile the values of the abundance of Li theoretical and observed in these rich in Li giants, but any of them bring conclusive answers. In the present work, we propose a qualitative study of the evolutionary state of the rich in Li stars in the literature along with the recent discovery of the first star rich in Li observed by the Kepler Satellite. The main objective of this work is to promote a solid discussion about the evolutionary state based on the characteristic obtained from the seismic analysis of the object observed by Kepler. We used evolutionary traces and simulation done with the population synthesis code TRILEGAL intending to evaluate as precisely as possible the evolutionary state of the internal structure of these groups of stars. The results indicate a very short characteristic time when compared to the evolutionary scale related to the enrichment of these stars

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Family Health Program (FHP) presents itself as a restructured model on basic cares besides having prevention practices and promotion in health as essential parts. According to that, the purpose of this study is to perceive which prevention practices in oral health are accomplished by the dentists from the FHP of Natal-RN as well as the way they have been developed, the knowledge basis to execute the procedure and the use of evaluation instruments by the dentists and by the Oral Health Co-Ordinator. A list of dentists participating on the FHP of Natal in March, 2006 (n= 91) was obtained so it was possible to formulate a structured interview. After excluding those with less than six months attending to the program, and considering the loss, eighty dentists got to be interviewed. It had questions about individual and group preventive procedures, sources of basement to develop the activities and to verify the impact and evaluation instruments. Besides that, an interview was made with the Oral Health Co-Ordinator about the evaluating process and the existence of a protocol as well as about document analysis in the Ambulatory Informations System Unique Health System (AIS-UHS), Information of Basic Care System and Pact of Recorder. The main individual activities consist on Oral Hygiene Orientation (87,5%) and Fluoridization (95%). Group activities remain at scholar groups acts(91,25%) being fluoridization done by 91,25% and educative activities by 86,25% mainly through speeches (61,25%).Orientations about oral cancer were detached on the aged group (39,96%)and hypertensive and diabetic group (19,51%), as well as integration with the health team was respectively 21,93% and 39,02%. Speeches and talk rounds are the main activities for aged, hypertensive and diabetics, and are also expressive to pregnant women. For pregnant women and babies group predominate hygiene and diet orientation. About the evaluation instruments 73,75% of the dentists do not consider their existence, despite 73,75% consider that actions have impact specially due to a increase of hygiene and decrease of caries index on the children. The main sources of basement are clinical experience (42,5%) and preparative courses (33,75%), only 7,5% mentioned population need and local reality. The Oral Health Co-Ordinator related the Attention Pact Recorder and records from the AIS - UHS as evaluation source but also detached the lack of epidemiologic surveying. She mentioned the increase of supervised brushing as a positive result and detached the hardness of the professional to act inside the family and as a team. The AIS-UHS records showed that fluoridization is more used individually and the supervised brushing is predominant as a group action, besides that educative activities at the Health Establishment predominate due to actions at the community. Facing the results, it was verified the act in different groups, special attention given to scholars, as well as focus the activities on caries giving less emphasis to other oral problems. Despite that, there was no epidemiologic instruments or data of the local reality to guide the actions and to be part of the planning and evaluation process

Relevância:

10.00% 10.00%

Publicador:

Resumo:

TiTanate NanoTubes (TTNT) were synthesized by hydrothermal alkali treatment of TiO2 anatase followed by repeated washings with distinct degrees of proton exchange. TTNT samples with different sodium contents were characterized, as synthesized and after heattreatment (200-800ºC), by X-ray diffraction, scanning and transmission electron microscopy, electron diffraction, thermal analysis, nitrogen adsorption and spectroscopic techniques like FTIR and UV-Vis diffuse reflectance. It was demonstrated that TTNTs consist of trititanate structure with general formula NaxH2−xTi3O7·nH2O, retaining interlayer water in its multiwalled structure. The removal of sodium reduces the amount of water and contracts the interlayer space leading, combined with other factors, to increased specific surface area and mesopore volume. TTNTs are mesoporous materials with two main contributions: pores smaller than 10 nm due to the inner volume of nanotubes and larger pores within 5-60 nm attributed to the interparticles space. Chemical composition and crystal structure of TTNTs do not depend on the average crystal size of the precursor TiO2-anatase, but this parameter affects significantly the morphology and textural properties of the nanostructured product. Such dependence has been rationalized using a dissolution-recrystallization mechanism, which takes into account the dissolution rate of the starting anatase and its influence on the relative rates of growth and curving of intermediate nanosheets. The thermal stability of TTNT is defined by the sodium content and in a lower extent by the crystallinity of the starting anatase. It has been demonstrated that after losing interlayer water within the range 100-200ºC, TTNT transforms, at least partially, into an intermediate hexatitanate NaxH2−xTi6O13 still retaining the nanotubular morphology. Further thermal transformation of the nanostructured tri- and hexatitanates occurs at higher or lower temperature and follows different routes depending on the sodium content in the structure. At high sodium load (water washed samples) they sinter and grow towards bigger crystals of Na2Ti3O7 and Na2Ti6O13 in the form of rods and ribbons. In contrast, protonated TTNTs evolve to nanotubes of TiO2(B), which easily convert to anatase nanorods above 400ºC. Besides hydroxyls and Lewis acidity typical of titanium oxides, TTNTs show a small contribution of protonic acidity capable of coordinating with pyridine at 150ºC, which is lost after calcination and conversion into anatase. The isoeletric point of TTNTs was measured within the range 2.5-4.0, indicating behavior of a weak acid. Despite displaying semiconductor characteristics exhibiting typical absorption in the UV-Vis spectrum with estimated bandgap energy slightly higher than that of its TiO2 precursor, TTNTs showed very low performance in the photocatalytic degradation of cationic and anionic dyes. It was concluded that the basic reason resides in its layered titanate structure, which in comparison with the TiO2 form would be more prone to the so undesired electron-hole pair recombination, thus inhibiting the photooxidation reactions. After calcination of the protonated TTNT into anatase nanorods, the photocatalytic activity improved but not to the same level as that exhibited by its precursor anatase

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Non-Photorealisitc Rendering (NPR) is a class of techniques that aims to reproduce artistic techniques, trying to express feelings and moods on the rendered scenes, giving an aspect of that they had been made "by hand". Another way of defining NPR is that it is the processing of scenes, images or videos into artwork, generating scenes, images or videos that can have the visual appeal of pieces of art, expressing the visual and emotional characteristics of artistic styles. This dissertation presents a new method of NPR for stylization of images and videos, based on a typical artistic expression of the Northeast region of Brazil, that uses colored sand to compose landscape images on the inner surface of glass bottles. This method is comprised by one technique for generating 2D procedural textures of sand, and two techniques that mimic effects created by the artists using their tools. It also presents a method for generating 21 2D animations in sandbox from the stylized video. The temporal coherence within these stylized videos can be enforced on individual objects with the aid of a video segmentation algorithm. The present techniques in this work were used on stylization of synthetic and real videos, something close to impossible to be produced by artist in real life

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Currently the interest in large-scale systems with a high degree of complexity has been much discussed in the scientific community in various areas of knowledge. As an example, the Internet, protein interaction, collaboration of film actors, among others. To better understand the behavior of interconnected systems, several models in the area of complex networks have been proposed. Barabási and Albert proposed a model in which the connection between the constituents of the system could dynamically and which favors older sites, reproducing a characteristic behavior in some real systems: connectivity distribution of scale invariant. However, this model neglects two factors, among others, observed in real systems: homophily and metrics. Given the importance of these two terms in the global behavior of networks, we propose in this dissertation study a dynamic model of preferential binding to three essential factors that are responsible for competition for links: (i) connectivity (the more connected sites are privileged in the choice of links) (ii) homophily (similar connections between sites are more attractive), (iii) metric (the link is favored by the proximity of the sites). Within this proposal, we analyze the behavior of the distribution of connectivity and dynamic evolution of the network are affected by the metric by A parameter that controls the importance of distance in the preferential binding) and homophily by (characteristic intrinsic site). We realized that the increased importance as the distance in the preferred connection, the connections between sites and become local connectivity distribution is characterized by a typical range. In parallel, we adjust the curves of connectivity distribution, for different values of A, the equation P(k) = P0e

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The present dissertação had as objective to study the ambient management in the Farms Saint Rita, Tahim Agropesca and Agropesca Rigomoleiro, in the Great River of the North. For this we use as theoretical tool some fundantes concepts of geographic science, the space, and as concepts auxiliary of ambient management, of estuaries as the half natural one and of manguezais as ecosystem. The study if it gave taking in consideration a model of flow of activities of a typical farm following the way of the residues produced since the beginning until its final destination, in a suitable script of SCHERER (1999). The considered flow established a sequence activities where it is identified the material of entrance, the process of management, the residues of exit and the destination of the residues to the long one of the phase of culture of the shrimp. From it was there had been elaborated a series of managemental pictures with the data raised in the three farms, of different transports and concludes that the ambient management of these farms does not follow the formal standards of a system of typical ambient management. Collating with the system of considered by norm ISO14000 the study it disclosed that all the companies are in a situation of not conformity and that the impacts on the environment continue being many significant ones. However, it is possible to implant norm ISO14000 because some procedures implanted for the farms are correct of the point of view of the ambient management

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Nanoemulsions are emulsified systems, characterized for reduced droplet size (50- 500nm), which the main characteristic are kinect stability and thermodynamic instability. These are promising systems on cosmetic area due to their droplet size that provide different advantages when compared to conventional systems, among others, larger surface area and better permeability. The Opuntia ficus-indica (L.) Mill is a plant cultivated on Caatinga Brazilian biome, which has great socioeconomic importance to region. This plant shows carbohydrates utilized for cosmetic industry as moisturizing active in their chemical composition. The aim of study was to develop, characterize, evaluate stability and moisturizing efficacy of cosmetic nanoemulsions added to Opuntia ficus-indica (L.) Mill extract. Nanoemulsions preparation was made using a low energy method. Different nanoemulsions were formulated varying the ratio of oil, water and surfactant phases beyond xanthan gum (0.5% e 1%) and Opuntia ficus-indica (L.) Mill hydroglycolic extract addition on 1% and 3%. Obtained nanoemulsions were submitted to preliminary and accelerated stability tests. The evaluated parameters monitored were: macroscopic aspect, pH value, droplet size, zeta potential and polydispersion index, during 60 days on different temperatures. Stable formulations were submitted to moisturizing efficacy assessment by capacitance and transepidermal water loss methodologies during 5 hours. Stable samples were white and showed homogeneous and fluid aspect, pH value was inside ideal range (4,5-6,0) to topical application and droplet size under 200nm characterizing these system as nanoemulsions. Developed nanoemulsions did not decrease transepidermal water loss, however increased the water content on stratum corneum, highlighting the nanoemulsions containing 0.5% of xanthan gum and 1% of hydroglycolic extract. This work presents cosmetic moisturizing nanoemulsions composed to vegetal raw material from Brazilian Caatinga with potential to be used on cosmetic area.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This doctoral dissertationproposes the description, interpretation and analysis of the compositional structure of thesis and dissertation abstracts, with regard to the linguistic mechanisms that evidence text zones of different typological sequences, such as those of the text plan. Along these lines, the research problem was developed from the notion of compositional structure (sequences and text plans), as one of the levels or plans of text analysis, according to the theoretical framework proposed by Jean-Michel Adam (2011a). The main objective of this study was to recognize how the compositional structure, of thesis and dissertation abstracts, is achieved, with respect to text units and the global organization of this text category. The hypothesis posed in this research posits that specific informational text composition categories of abstracts are necessary to process the representation of the original text and the way in which it makes its meaning. Subsequently, this study is based on the theoretical and methodological framework of Text Linguistics (TL) and, above all, Textual Discourse Analysis (TDA), as we endeavor to understand the organizational structure of abstracts from both a linguistic and textual perspective. This structure involves the text plan of abstracts, with respect to their communicative purpose, i.e, the sharing of scientific information in its standard textual form. Thus, the development of this study, from a theoretical and methodological perspective, is based on the theoretical and descriptive premises from TDA (ADAM, 2011a, 2012; PASSEGGI et al., 2010), and also from TL (BEAUGRANDE; DRESSLER, (2012 [1981]); COSERIU; LAMAS (2010); MARCUSCHI, 2009 [1983]; FÁVERO; KOCH, 1994;KOCH, 2006; BENTES, 2004; BENTES; LEITE, 2010), within the field of text studies. The methodology of this study relies on empirical, documental research, which is qualitative, and adopts a descriptive and interpretive approach. From the empirical perspective, our objective is to understand the problems pertaining to the textual composition of abstracts, aiming to elucidate them in light of the theoretical and methodological framework previously mentioned. The corpus of the analysis is comprised of seven abstracts designated for systematic data collection. These texts, written between 2004 and 2011,were selected from Master’s theses and Doctoral dissertations in their electronic version, from the graduate program at the Federal University of Rio Grande do Norte. A thorough review of the literature reveals a clear fluctuation in the terminology of the concept, ‘abstract’. The results of the analysis revealed that the abstracts, which comprise the corpus of analysis in this study, in general, present typological heterogeneity, while the text plan remains fixed. Finally, the new knowledge gained in this research contributes both to the understanding of the compositional structure of abstracts as well as their production.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The skin is one of the largest organs of the human body and accounts for about 16% of body weight. The body protection against the external environment microorganisms is one of its most important functions, however is necessary that the skin remain intact for this function be exercised, so that when there is an injury on the skin, the process of restructuring needs to be starts, however this restructuration may also be compromised due to some diseases, justifying even more the need for the development of topical products that promote or accelerate the skin healing. Thus the aim of this study was to extract bullfrog oil and to develop a suitable topical emulsion. Two different oil samples were extracted by hot or organic solvent process. Titration techniques and gas chromatography- mass spectrometry were used to characterize the bullfrog oil. The required hydrophile-lipophile balance (HLBr) of bullfrog oil was determined and a pseudo-ternary phase diagram was constructed. The stability of the topical emulsion was evaluated. Then, cellular viability was determined by MTT assay using normal fibroblasts (3T3) and melanoma (B16F10) cells lines. The hot extraction yield was 60.6%. The major polyunsaturated compounds found were Eicosapentaenoic acid (17.6%) and Arachidonic acid (8.4%). HLBr study demonstrated the presence of stable systems with HLB ranging from 12.1 to 13.5 and the pseudo-ternary phase diagram showed mainly emulsion systems (62%). Topical emulsion showed 390 nm, polydispersity 0.05, zeta potential -25 mV and remained stable for ninety days. The bullfrog oil and topical emulsion did not showed citotoxicity in normal fibroblasts cells. However, these systems showed significantly inhibition of melanoma cells growth. In conclusion, the bullfrog oil presented desirable chemical characteristics required to be used for the development of a pharmaceutical and cosmetic products.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Actinic cheilitis (AC) is a potentially malignant disorder which affects the lip vermilion and results from chronic exposure to sunlight. Currently, it is not possible to predict which cases of AC may progress to squamous cell carcinoma, and therefore, some biomolecular markers have been researched. Cyclooxygenase 2 (COX-2) is an enzyme associated with inflammatory response which is overexpressed in oral cancer; however, little is known about the role of this protein in actinic cheilitis. About the treatment of this lesion, currently available therapeutic modalities to AC may cause cytotoxic effects and deleterious results to patients. Therefore, the aim of this study was to evaluate the immunoexpression of COX-2 in AC of different risks of malignant transformation and analyse, through clinical follow-up, the efficacy of diclofenac sodium 3% gel in the treatment of this condition. Epithelial immunoexpression of COX-2 was analysed semi-quantitatively in 90 cases of AC classified as low risk (n = 55) and high risk (n = 35) of malignant transformation, in which the scores were assigned: (0) 0 to 5% of positive cells - Negative; (1) 6 to 30% of positive cells - Low expression; (2) 31 to 100% of positive cells - High expression. The chi-square test of Pearson was conducted to verify possible associations between immunoexpression of COX-2 and histologic grade of actinic cheilitis. The weighted kappa coefficient denoted a good interobserver agreement (0.677). Nineteen patients diagnosed with AC were instructed to perform topical application of the gel three times a day for a period of 90 days. In each biweekly visit, a follow-up record was accomplished through digital photographs and after treatment was completed, two researchers analysed all the images to assess clinical aspects of the lip. Furthermore, tolerability to the drug and patient satisfaction after treatment were evaluated. COX-2 was overexpressed in 74.4% of AC cases. Both low and high-risk groups revealed predominance of score 3, followed by scores 2 and 1. There was no significant association (p = 0.315) between COX-2 expression and histological grading. Among the total number of participants of this clinical study, ten showed total remission of all clinical features of the lesion and three had partial improvement of these characteristics. One participant presented worsening of the clinical condition. In five cases, the treatment was discontinued due to development of mild adverse effects at the site of gel application. Regarding analysis of satisfaction and tolerability to the drug, most patients were fully satisfied with the therapy (n = 11) and reported that the drug was not irritating to the lips (n = 9). Our study demonstrates that high expression of COX-2 is common in AC; however, this protein was not associated with malignant transformation risk of the analysed cases. Topical application of diclofenac sodium 3% gel provided a convenient and well tolerated approach in most cases, and may be a promising alternative for the treatment of actinic cheilitis.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This dissertation addresses issues considered essential for sustainable development of urban waterfronts and beaches. Many of these spaces, even though they are of public authorities, economic market and general population interests - due to its landscape, its importance for recreation purposes and as a basis of " Sun and beach Tourism " (Turismo de Sol e Praia), among other factors - have shown aesthetic, health and cultural degradation, entailing environmental, economic and social losses and conflicts. Based on this perception, the research aims to understand the main reasons for these negative results for beach spaces. To this end, it was chosen the case study of a typical urban beach, Ponta Negra Beach, located in Natal, RN. Ponta Negra is associated with the "postcard" of the city and it has been deserving of municipal urban planning legislation that legally recognizes the importance of its landscape. Also it has received constant investments by the Government through urban projects, arguing to leave the site attractive to its users. Nevertheless, in the last fifteen years, the beach has lived with the expansion of its problems, such as those related to bathing water, to coastal erosion, and to the mangling of its natural surroundings. Social conflicts have also been frequent in this time frame: conflicts between residents of the waterfront and traders who work on the beach, between the traders themselves, between the managers of space and fishermen, between managers and formal and informal traders. Many of these social and environmental conflicts have taken such grand proportions that became legal matters. Assuming that the problems identified are related to the issue of rationality - understood as a system of values, norms and actions that relate means and ends - and upholding the need for focused research on "environmental rationality" to understand and interpret the dynamics of social and environmental problems encountered on site, the research that guides the study relies on the Mexican economist Enrique Leff's theory on "environmental rationality" which, briefly, can be defined as a system of values, norms, actions and means and ends relations based on the principles of environmental management and sustainable development. Among other aspects, rationality encompasses cross-sectional planning of public administration, the participation of society in the management of environmental resources, interdisciplinary reorganization of knowledge, the clash of opposing interests and the conciliation of common goals of different social actors. The study evaluates the relationship between "environmental rationality", as proposed by Enrique Leff, with the management, urban interventions and uses observed in Ponta Negra Beach. For that, some benchmarks were established and considered in the research as related to sustainable development of the "beachy" atmosphere. Analytical instruments chosen were the urban transformations and the environmental and social problems that have been the target of lawsuits. Also part of the study, the problems that were the subject of civil investigations, which are investigation procedures carried out by the Prosecutor's Office.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This dissertation addresses issues considered essential for sustainable development of urban waterfronts and beaches. Many of these spaces, even though they are of public authorities, economic market and general population interests - due to its landscape, its importance for recreation purposes and as a basis of " Sun and beach Tourism " (Turismo de Sol e Praia), among other factors - have shown aesthetic, health and cultural degradation, entailing environmental, economic and social losses and conflicts. Based on this perception, the research aims to understand the main reasons for these negative results for beach spaces. To this end, it was chosen the case study of a typical urban beach, Ponta Negra Beach, located in Natal, RN. Ponta Negra is associated with the "postcard" of the city and it has been deserving of municipal urban planning legislation that legally recognizes the importance of its landscape. Also it has received constant investments by the Government through urban projects, arguing to leave the site attractive to its users. Nevertheless, in the last fifteen years, the beach has lived with the expansion of its problems, such as those related to bathing water, to coastal erosion, and to the mangling of its natural surroundings. Social conflicts have also been frequent in this time frame: conflicts between residents of the waterfront and traders who work on the beach, between the traders themselves, between the managers of space and fishermen, between managers and formal and informal traders. Many of these social and environmental conflicts have taken such grand proportions that became legal matters. Assuming that the problems identified are related to the issue of rationality - understood as a system of values, norms and actions that relate means and ends - and upholding the need for focused research on "environmental rationality" to understand and interpret the dynamics of social and environmental problems encountered on site, the research that guides the study relies on the Mexican economist Enrique Leff's theory on "environmental rationality" which, briefly, can be defined as a system of values, norms, actions and means and ends relations based on the principles of environmental management and sustainable development. Among other aspects, rationality encompasses cross-sectional planning of public administration, the participation of society in the management of environmental resources, interdisciplinary reorganization of knowledge, the clash of opposing interests and the conciliation of common goals of different social actors. The study evaluates the relationship between "environmental rationality", as proposed by Enrique Leff, with the management, urban interventions and uses observed in Ponta Negra Beach. For that, some benchmarks were established and considered in the research as related to sustainable development of the "beachy" atmosphere. Analytical instruments chosen were the urban transformations and the environmental and social problems that have been the target of lawsuits. Also part of the study, the problems that were the subject of civil investigations, which are investigation procedures carried out by the Prosecutor's Office.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

GALVÃO, Marise Adriana Mamede; RODRIGUES, Maria das Graças Soares.(Des) encontros no discurso de estagiário em relatórios de estágio supervisionados. Revista Intercâmbio, São Paulo, v.18, p. 122-138, 2008.ISSN 1806-275x

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Os fatores de crescimento são substâncias moduladoras do processo de cicatrização. O fator de crescimento de fibroblastos básico (FCFß) liberado pelas plaquetas, macrófagos e pelos próprios fibroblastos, estimulam a proliferação celular, a produção de colágeno e de outros elementos da matriz celular, favorecendo o processo da cicatrização, mesmo em situações adversas, como diabetes e uso de corticosteróides. O presente estudo objetivou determinar a influência do FCFb no processo de cicatrização de anastomoses esofageanas em modelo de experimentação animal, avaliando-se a resistência à pressão,formação de tecido de granulação e deposição de colágeno. Método: Foram estudados dois grupos A e B,ambos com 10 ratos de linhagem Wistar, separados de forma aleatória, todos submetidos à secção e anastomose do esôfago por via abdominal. Nos animais do grupo A, foi feita aplicação tópica na linha de sutura de 10ng de FCFb. No grupo B (controle) foi aplicado igual volume de solução salina. Os animais foram sacrificados no 7º dia, o esôfago ressecado para teste de resistência da anastomose, estudo qualitativo do aporte de células inflamatórias, da angiogênese e quantificação do colágeno na zona da anastomose, através de sistema digital. Resultados: A densidade média dos parâmetros histológicos do grupo A foi 9095,51±1284,5, maior que no grupo B, que teve densidade 7162,4±1273,19 (p=0,013). A resistência da anastomose do grupo A teve a média 210±18,88 mmHg, significativamente maior que no grupo B, que atingiu o valor 157±29,55 mmHg (p=0,0024). Conclusão: Este estudo concluiu que o FCFß atuou melhorando a cicatrização e aumentando significativamente a resistência de anastomoses do esôfago realizadas em ratos

Relevância:

10.00% 10.00%

Publicador:

Resumo:

RESUMO: Objetivo: Avaliar as alterações histológicas, e o ganho de resistência em anastomoses duodenais tratadas com fator de crescimento de fibroblasto básico (FGFb). Métodos: Vinte ratos da raça Wistar foram submetidos a secção transversal do duodeno, seguida de anastomose. Os animais foram divididos em 4 grupos de 5 animais cada: A1 e A2 (experimentais), nos quais foi aplicado FCFb sobre a anastomose logo após seu término; e B1 e B2 (controles), nos quais foi administrada solução salina sobre a zona de anastomose. Os roedores foram mortos com superdose de anestésico, sendo A1, B1 no 5º dia e A2, B2 no 7º dia de pós-operatório. Foi feita avaliação quanto à resistência das anastomoses à pressão e análise da densidade média dos achados histopatológicos com auxílio do sistema digitalizado Image proPlus. Resultados: No grupo A1 a pressão suportada pelas anastomoses foi de 52±14,4 mmHg e no grupo A2 140±34,8 mmHg. Em B1 a pressão atingiu 33,6±15,2 mmHg e as anastomoses do grupo B2 suportaram pressão 105±30,3. No grupo A1 a densidade média dos elementos histopatológicos foi de 93±9,3 e A2 atingiu 181,8±27,6. Nos grupos de controle B1 e B2 as densidades médias foram 67,6±16,7 e 101±12,9 respectivamente. A análise estatística revelou diferença significante entre nos dados dos grupos experimentais e controles (p<0,05).Conclusão: a aplicação tópica do FCFb foi capaz de aumentar a resistência das feridas do duodeno suturadas e observadas após 5 e 7 dias de evolução. Estimulou a neovascularização, a formação de fibroblastos e de fibras colágenas, melhorando os escores histológicos em relação ao controle.