73 resultados para Change Period
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OBJECTIVES: To evaluate the use of inhaled nitric oxide (NO) in the management of persistent pulmonary hypertension of the newborn. METHODS: Computerized bibliographic search on MEDLINE, CURRENT CONTENTS and LILACS covering the period from January 1990 to March 1998; review of references of all papers found on the subject. Only randomized clinical trials evaluating nitric oxide and conventional treatment were included. OUTCOMES STUDIED: death, requirement for extracorporeal membrane oxygenation (ECMO), systemic oxygenation, complications at the central nervous system and development of chronic pulmonary disease. The methodologic quality of the studies was evaluated by a quality score system, on a scale of 13 points. RESULTS: For infants without congenital diaphragmatic hernia, inhaled NO did not change mortality (typical odds ratio: 1.04; 95% CI: 0.6 to 1.8); the need for ECMO was reduced (relative risk: 0.73; 95% CI: 0.60 to 0.90), and the oxygenation was improved (PaO2 by a mean of 53.3 mm Hg; 95% CI: 44.8 to 61.4; oxygenation index by a mean of -12.2; 95% CI: -14.1 to -9.9). For infants with congenital diaphragmatic hernia, mortality, requirement for ECMO, and oxygenation were not changed. For all infants, central nervous system complications and incidence of chronic pulmonary disease did not change. CONCLUSIONS: Inhaled NO improves oxygenation and reduces requirement for ECMO only in newborns with persistent pulmonary hypertension who do not have diaphragmatic hernia. The risk of complications of the central nervous system and chronic pulmonary disease were not affected by inhaled NO.
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Triple therapy is accepted as the treatment of choice for H. pylori eradication. In industrialized countries, a proton pump inhibitor plus clarithromycin and amoxicillin or nitroimidazole have shown the best results. Our aims were: 1. To study the eradication rate of the association of a proton pump inhibitor plus tinidazole and clarithromycin on H. pylori infection in our population. 2. To determine if previous treatments, gender, age, tobacco, alcohol use, and non-steroidal anti-inflammatory drugs (NSAIDs) change the response to therapy. METHODS: Two hundred patients with peptic ulcer (upper endoscopy) and H. pylori infection (histology and rapid urease test - RUT) were included. A proton pump inhibitor (lansoprazole 30 mg or omeprazole 20 mg), tinidazole 500 mg, and clarithromycin 250 mg were dispensed twice a day for a seven-day period. Eradication was assessed after 10 to 12 weeks of treatment through histology and RUT. RESULTS: The eradication rate of H. pylori per protocol was 65% (128/196 patients). This rate was 53% for previously treated patients, rising to 76% for not previously treated patients, with a statistical difference p<0.01. No significant difference was observed regarding sex, tobacco use, alcohol consumption, and NSAID use, but for elderly patients the difference was p = 0.05. Adherence to treatment was good, and side effects were mild. CONCLUSIONS: A proton pump inhibitor, tinidazole, and clarithromycin bid for seven days resulted in H. pylori eradication in 65% of the patients. Previous treatments were the main cause of treatment failure.
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Nutrition is essential for maintenance of physiologic homeostasis and growth. Hypermetabolic states lead to a depletion of body stores, with decreased immunocompetence and increased morbidity and mortality. The purpose of this paper is to provide an update regarding the provision of appropriate nutrition for the pediatric surgical patient, emphasizing the preoperative and postoperative periods. Modern nutritional support for the surgical patient comprises numerous stages, including assessment of nutritional status, nutritional requirements, and nutritional therapy. Nutritional assessment is performed utilizing the clinical history, clinical examination, anthropometry, and biochemical evaluation. Anthropometric parameters include body weight, height, arm and head circumference, and skinfold thickness measurements. The biochemical evaluation is conducted using determinations of plasma levels of proteins, including album, pre-albumin, transferrin, and retinol-binding protein. These parameters are subject to error and are influenced by the rapid changes in body composition in the peri-operative period. Nutritional therapy includes enteral and/or parenteral nutrition. Enteral feeding is the first choice for nutritional therapy. If enteral feeding is not indicated, parenteral nutrition must be utilized. In all cases, an individualized, adequate diet (enteral formula or parenteral solution) is obligatory to decrease the occurrence of overfeeding and its undesirable consequences.
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PURPOSE: Patients preparing to undergo surgery should not suffer needless anxiety. This study aimed to evaluate anxiety levels on the day before surgery as related to the information known by the patient regarding the diagnosis, surgical procedure, or anesthesia. METHOD: Patients reported their knowledge of diagnosis, surgery, and anesthesia. The Spielberger State-Trait Anxiety Inventory (STAI) was used to measure patient anxiety levels. RESULTS: One hundred and forty-nine patients were selected, and 82 females and 38 males were interviewed. Twenty-nine patients were excluded due to illiteracy. The state-anxiety levels were alike for males and females (36.10 ± 11.94 vs. 37.61 ± 8.76) (mean ± SD). Trait-anxiety levels were higher for women (42.55 ± 10.39 vs. 38.08 ± 12.25, P = 0.041). Patient education level did not influence the state-anxiety level but was inversely related to the trait-anxiety level. Knowledge of the diagnosis was clear for 91.7% of patients, of the surgery for 75.0%, and of anesthesia for 37.5%. Unfamiliarity with the surgical procedure raised state-anxiety levels (P = 0.021). A lower state-anxiety level was found among patients who did not know the diagnosis but knew about the surgery (P = 0.038). CONCLUSIONS: Increased knowledge of patients regarding the surgery they are about to undergo may reduce their state-anxiety levels.
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Changes in the floristic composition over an eight-year period in a logged area at the Tapajós National Forest in Brazilian Amazonia arc discussed. Two treatments of different intensities of logging were compared with an undisturbed (control) forest. Data were collected from permanent sample-plots. The effects of logging on floristic composition were stronger in the more heavily logged treatment. The number of species decreased immediately after logging, but started to increase before the fifth year after logging and was higher at the end of the study period than before logging. The more heavily logged plots responded more to disturbances, as judged by the increase in the number of species during the period after logging. This forest appears to recover its initial floristic composition after disturbance without intervention.
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This study examined the stress response of pirarucu juveniles in a closed system transport. Pirarucu (Arapaima gigas) is a native Amazonian fish species from the Osteoglossidae family and an obligated air breather. A short duration transport trial (6h) was undertaken comparing closed polyethylene bags filled with atmospheric air (Air group) and bags filled with pure oxygen (Oxi group). Dissolved oxygen was the only water parameter that presented a difference between fish groups, and was saturated in the oxi group as expected. There was no mortality in either group after transport. Fish feeding was observed 36 h after transport for all fish, and normal feeding consumption was observed at 72 h. In both groups physiological responses were similar. Cortisol did not show any significant alteration during the sampled period. Unlike most fish species, cortisol values were unaltered in both groups during sampling, while glucose presented a significant change up to 12 h after transport. The results showed that pirarucu transport in plastic bags could be made with either atmospheric air or pure oxygen, since physiological response to stress, water quality and feeding behavior after 36 h were similar in both groups.
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This paper deals with growth rates of trees > 5cm dbh over an eight-year period from 257 species at the Tapajós National Forest. The discussion is centred on the behaviour of the forest after logging. Permanent sample plots were established in 1981 and measured at the first time. The area was logged in 1982. Measurements after logging occurred in 1983, 1987 and 1989. Considering all species together, diameter increment was similar for both intensities of logging until five years after logging. Light-demanding species showed significantly higher growth rates than shade-tolerant species in the logged forest, with greater increment in the heavier treatment intensity. Commercial species also had higher growth rates in the heavier logged area, although those were significantly different only in the period from one to five years after logging. In the undisturbed forest, growth rates increased with increasing dbh size. At species level, growth rate varied between and within treatments, as well as between trees within species, depending mainly on degree of canopy opening. The logging favoured the growth of commercial species, chiefly the light-demanders. Therefore, if the same growth conditions continue being given, for example by silvicultural treatments, to those species of commercial interest, the forest would reach a stock available for harvesting around year 30 after logging. However, the high variation in increment rates indicates that an eight-year period is not sufficient to allow predictions on cutting cycles or polycyclic management systems for the study forest.
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The addition of salt to the water has been used to mitigate stress and improve survival in fishes. This study investigated the effects of sodium chloride (0.0, 1.0, 3.0 and 6.0 g/l) on levels of plasma cortisol, glucose, tryacilglycerol, total protein, hematocrit, hemoglobin, erythrocyte number, liver glycogen and lipid, and muscle lipid in adult matrinxã(Brycon amazonicum) after a 4-h transport and during a 96-h recovery period. Fish were sampled before and after transport, and 24 and 96 h of the recovery period. Plasma cortisol was higher than initial condition immediately after transportation, except in fish transported in 3.0 and 6.0 g/l of salt. A similar pattern was observed for blood glucose but fish transported in water with 0.0, 1.0 and 3.0 g/l of salt needed more than 24 h to return to the initial condition. Liver glycogen was lower after transport in fish not exposed to salt. Hemoglobin, erythrocyte number, total plasma protein and liver lipid did not change during the experiment but hematocrit was lower after transport in all treatments and returned to pre-transport values in 24 h. Reductions of muscle lipid and plasma tryacilglycerol were observed during the recovery period in fish from all treatments. The results show that 6.0 g/l NaCl added to the transport water reduce the stress responses and a 96-h recovery period is needed if no salt is used to mitigate the stress.
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The purpose of this study is to evaluate in vitro the color stability of composite resins when exposed to beverages with high coloring contents from the Amazon region. 240 samples from four different composite brands (Natural Look, Z350, 4Seasons and Opallis) of hue A3 were fabricated using an acrylic matrix. The samples were stored in distilled water at 37ºC for 24 hours. The initial color (T0) was registered using a Canon EOS Rebel XTi 10 mp camera, and then the samples were divided into four groups (n=15): G1 (coffee), G2 (açaí juice), G3 (energetic guaraná) and G4 (control - distilled water). The samples were exposed to solutions of DES (6hs) and RE (18hs) and placed in a double boiler under constant agitation, at 37ºC for 30 days. The samples were immersed in the coloring solutions for 15 minutes daily. After 7, 15 and 30 days, new photographic registers were made (T1, T2 and T3). The images were analyzed using Corel PHOTO-PAINT 12 software to identify the colors through the HSB system. The Kruskal-Wallis and t tests (p<0.05) demonstrated significant differences in color (hue, saturation and brightness). The results revealed that none of the tested composites showed color stability when exposed to coloring solutions, and that the Amazon region beverages (açaí juice and energetic guaraná) showed to be less coloring than coffee.
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Land cover changes over time as a result of human activity. Nowadays deforestation may be considered one of the main environmental problems. The objective of this study was to identify and characterize changes to forest cover in Venezuela between 2005-2010. Two maps of deforestation hot spots were generated on the basis of MODIS data, one using digital techniques and the other by means of direct visual interpretation by experts. These maps were validated against Landsat ETM+ images. The accuracy of the map obtained digitally was estimated by means of a confusion matrix. The overall accuracy of the maps obtained digitally was 92.5%. Expert opinions regarding the hot spots permitted the causes of deforestation to be identified. The main processes of deforestation were concentrated to the north of the Orinoco River, where 8.63% of the country's forests are located. In this region, some places registered an average annual forest change rate of between 0.72% and 2.95%, above the forest change rate for the country as a whole (0.61%). The main causes of deforestation for the period evaluated were agricultural and livestock activities (47.9%), particularly family subsistence farming and extensive farming which were carried out in 94% of the identified areas.
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Coupled carbon/climate models are predicting changes in Amazon carbon and water cycles for the near future, with conversion of forest into savanna-like vegetation. However, empirical data to support these models are still scarce for Amazon. Facing this scenario, we investigated whether conservation status and changes in rainfall regime have influenced the forest-savanna mosaic over 20 years, from 1986 to 2006, in a transitional area in Northern Amazonia. By applying a spectral linear mixture model to a Landsat-5-TM time series, we identified protected savanna enclaves within a strictly protected nature reserve (Maracá Ecological Station - MES) and non-protected forest islands at its outskirts and compared their areas among 1986/1994/2006. The protected savanna enclaves decreased 26% in the 20-years period at an average rate of 0.131 ha year-1, with a greater reduction rate observed during times of higher precipitation, whereas the non-protected forest islands remained stable throughout the period of study, balancing the encroachment of forests into the savanna during humid periods and savannization during reduced rainfall periods. Thus, keeping favorable climate conditions, the MES conservation status would continue to favor the forest encroachment upon savanna, while the non-protected outskirt areas would remain resilient to disturbance regimes. However, if the increases in the frequency of dry periods predicted by climate models for this region are confirmed, future changes in extension and directions of forest limits will be affected, disrupting ecological services as carbon storage and the maintenance of local biodiversity.
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ABSTRACTThe Amazon várzeas are an important component of the Amazon biome, but anthropic and climatic impacts have been leading to forest loss and interruption of essential ecosystem functions and services. The objectives of this study were to evaluate the capability of the Landsat-based Detection of Trends in Disturbance and Recovery (LandTrendr) algorithm to characterize changes in várzeaforest cover in the Lower Amazon, and to analyze the potential of spectral and temporal attributes to classify forest loss as either natural or anthropogenic. We used a time series of 37 Landsat TM and ETM+ images acquired between 1984 and 2009. We used the LandTrendr algorithm to detect forest cover change and the attributes of "start year", "magnitude", and "duration" of the changes, as well as "NDVI at the end of series". Detection was restricted to areas identified as having forest cover at the start and/or end of the time series. We used the Support Vector Machine (SVM) algorithm to classify the extracted attributes, differentiating between anthropogenic and natural forest loss. Detection reliability was consistently high for change events along the Amazon River channel, but variable for changes within the floodplain. Spectral-temporal trajectories faithfully represented the nature of changes in floodplain forest cover, corroborating field observations. We estimated anthropogenic forest losses to be larger (1.071 ha) than natural losses (884 ha), with a global classification accuracy of 94%. We conclude that the LandTrendr algorithm is a reliable tool for studies of forest dynamics throughout the floodplain.
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ABSTRACT: Despite the reduction in deforestation rate in recent years, the impact of global warming by itself can cause changes in vegetation cover. The objective of this work was to investigate the possible changes on the major Brazilian biome, the Amazon Rainforest, under different climate change scenarios. The dynamic vegetation models may simulate changes in vegetation distribution and the biogeochemical processes due to climate change. Initially, the Inland dynamic vegetation model was forced with initial and boundary conditions provided by CFSR and the Eta regional climate model driven by the historical simulation of HadGEM2-ES. These simulations were validated using the Santarém tower data. In the second part, we assess the impact of a future climate change on the Amazon biome by applying the Inland model forced with regional climate change projections. The projections show that some areas of rainforest in the Amazon region are replaced by deciduous forest type and grassland in RCP4.5 scenario and only by grassland in RCP8.5 scenario at the end of this century. The model indicates a reduction of approximately 9% in the area of tropical forest in RCP4.5 scenario and a further reduction in the RCP8.5 scenario of about 50% in the eastern region of Amazon. Although the increase of CO2 atmospheric concentration may favour the growth of trees, the projections of Eta-HadGEM2-ES show increase of temperature and reduction of rainfall in the Amazon region, which caused the forest degradation in these simulations.