GAS EXCHANGE IN YOUNG PLANTS OF Tabebuia aurea(Bignoniaceae Juss.) SUBJECTED TO FLOODING STRESS1

ABSTRACT The Paratudo (Tabebuia aurea) is a species occurring in the Pantanal of Miranda, Mato Grosso do Sul, Brazil, an area characterized by seasonal flooding. To evaluate the tolerance of this plant to flooding, plants aged four months were grown in flooded soil and in non-flooded soil (control group). Stomatal conductance, transpiration and CO2 assimilation were measured during the stress (48 days) and recovery (11 days) period, totalling 59 days. The values of stomatal conductance of the control group and stressed plants at the beginning of the flooded were 0.33 mol m-2s-1 and reached 0.02 mol m-2 s-1 (46th day) at the end of this event. For the transpiration parameter, the initial rate was 3.1 mol m s-1, and the final rate reached 0.2 or 0.3 mol m-2 s-1 (47/48 th day). The initial photosynthesis rate was 8.9 mmol m-2s-1 and oscillated after the sixth day, and the rate reached zero on the 48th day. When the photosynthesis rate reached zero, the potted plants were dried, and the rate was analyzed (11th day). The following values were obtained for dried plants: stomatal conductance = 0.26 mol m-2 s-1, transpiration rate = 2.5 mol m-2 s-1 and photosynthesis rate = 7.8 mmol m-2 s-1. Flooded soil reduced photosynthesis and stomatal conductance, leading to the hypertrophy of the lenticels. These parameters recovered and after this period, and plants exhibited tolerance to flooding stress by reducing their physiological activities.

Microgeneration of electricity with producer gas in dual fuel mode operation

Among the alternatives to meet the increasing of world demand for energy, the use of biomass as energy source is one of the most promising as it contributes to reducing emissions of carbon dioxide in the atmosphere. Gasification is a technological process of biomass energy production of a gaseous biofuel. The fuel gas has a low calorific value that can be used in Diesel engine in dual mode for power generation in isolated communities. This study aimed to evaluate the reduction in the consumption of oil Diesel an engine generator, using gas from gasification of wood. The engine generator brand used was a BRANCO, with direct injection power of 7.36 kW (10 HP) coupled to an electric generator 5.5 kW. Diesel oil mixed with intake air was injected, as the oil was injected via an injector of the engine (dual mode). The fuel gas was produced in a downdraft gasifier. The engine generator was put on load system from 0.5 kW to 3.5 kW through a set of electrical resistances. Diesel oil consumption was measured with a precision scale. It was concluded that the engine converted to dual mode when using the gas for the gasification of wood decreased Diesel consumption by up to 57%.

Evaluation of the heating of broilers in shed by means of gas hoods and underfloor heating

This study was conducted to evaluate and compare the behavior of the heating inside poultry shed through gas hood and underfloor heating. The experiment was conducted in poultry shed belonging to the Federal Institute of Education, Science and Technology of Triângulo Mineiro Region, Uberlândia city – state of Minas Gerais (MG), Brazil. The dimensions of the shed are 24 meters long and 9.6 meters wide and with a ceiling height of 3.2 meters. The temperature was measured with an optical thermometer of Minipa brand, MT 350 model. It was used, to the analysis of temperature behavior, the public domain software FEMM 4.2, which uses finite elements techniques, with data collected from two lots. Underfloor heating is made using hot water flowing through a serpentine type system, which is installed below the bed; this hot water is from solar heaters. An energetic and economic assessment of the warming shed for raising chickens was realized. From the results obtained with the simulations, it may observe that the heating through the floor provides a more homogeneous distribution of temperature when compared with the hood heating. The flow of heat is upwards supplying, thus, the greatest need of heating of the bird, which is the pectoral part.

Lymph node metastasis in early gastric cancer

OBJECTIVE: to evaluate the incidence of lymph node metastasis in early gastric cancer, identifying risk factors for its development. METHODS: we conducted a prospective study of patients with gastric cancer admitted to the Section of the Esophago-Gastric Surgery of the Surgery of Service HUCFF-UFRJ, from January 2006 to May 2012. RESULTS: the rate of early gastric cancer was 16.3%. The incidence of nodal metastases was 30.8% and occurred more frequently in patients with tumors with involvement of the submucosa (42.9%), in those poorly differentiated (36.4%), in tumors larger than 2 cm (33.3%) and in type III ulcerated lesions (43.8%). CONCLUSION: the incidence of lymph node metastases in patients was very high and suggests that one should keep the radicality of resection in early gastric cancer, particularly in relation to D2 lymphadenectomy, recommended for advanced gastric cancer. Conservative resections, with lymphadenectomies smaller than D2, should be performed only in selected cases, well-studied as for the risk factors of lymph node metastasis. Despite the small number of cases did not permit to relate the rate of lymph node metastasis to the risk factors considered, we noted a strong tendency for the occurrence of these metastases in the poorly differentiated, type III, larger than 2 cm tumors, and in the Lauren diffuse types.

Impact of Roux-en-Y gastric bypass on lipid and inflammatory profiles

Objective: To evaluate the behavior of acute phase proteins and lipid profile in patients undergoing Roux-en-Y gastric bypass. Methods : We conducted a prospective study, consisting of three moments: M1 - preoperative (24 hours before surgery); M2 - 30 days after surgery; and M3 - 180 days after surgery. We carried measured height and BMI, as well as determined the concentrations of acute phase proteins (C-reactive protein (CRP), albumin and Alpha-1-acid glycoprotein) and total cholesterol, LDL-c, HDL-c and triacylglycerol. Results : participants comprised 25 individuals, with a mean age of 39.28 ± 8.07, 72% female. At all times of the study there was statistically significant difference as for weight loss and BMI. We found a significant decrease in CRP concentrations between the moments M1 and M3 (p = 0.041) and between M2 and M3 (p = 0.018). There was decrease in Alpha-1-GA concentrations between M1 and M2 (p = 0.023) and between M1 and M3 (p = 0.028). The albumin values increased, but did not differ between times. Total cholesterol and triacylglycerol decreased significantly ay all times. LDL-c concentrations decreased and differed between M1 and M2 (p = 0.001) and between M1 and M3 (p = 0.001). HDL-c values increased, however only differing between M1 and M2 (p = 0.050). Conclusion : Roux-en-Y gastric bypass promoted a decrease in plasma concentrations of CRP and Alpha-1-acid glycoprotein, improving lipid and inflammatory profiles.

Blood-gas and electrolyte values for Amazon parrots (Amazona aestiva)

The aim was to provide reference data for blood gas/acid-base status and electrolytes for non-anesthetized Amazon parrots (Amazona aestiva). Thirty-five adult parrots from Tietê ecologic park were utilized. Arterial blood (0.3ml) samples were anaerobically collected from the superficial ulnar artery in heparinized (sodium heparin) 1-ml plastic syringes. The samples were immediately analyzed through a portable analyzer (i-STAT*, Abbot, Illinois, USA) with cartridges (EG7+). These data were grouped in such a way as to present both mean and standard deviation: body weight (360±37g), respiratory rate (82±33 b/m), temperature (41.8±0.6°C), hydrogen potential (7.452±0.048), carbon dioxide partial pressure (22.1±4.0mmHg), oxygen partial pressure (98.1±7.6mmHg), base excess (-7.9±3.1), plasma concentration of bicarbonate ions (14.8±2.8mmol/L), oxygen saturation (96.2±1.1%), plasma concentration of sodium (147.4±2.2mmol/L), plasma concentration of potassium (3.5±0.53mmol/L), plasma concentration of calcium (0.8±0.28mmol/L), hematocrit (38.7±6.2%) and concentration of hemoglobin (13.2±2.1g/dl). This study led us to conclude that, although the results obtained showed hypocapnia and low values of bicarbonate and base excess, when compared to other avian species, these data are very similar. Besides, in spite of the equipment being approved only for human beings, it was considered simple and very useful in the analysis of avian blood samples. By using this equipment we were able to provide references data for non-anaesthetized Amazon parrots.

Gastric ulcers in pigs affected with postweaning multisystemic wasting syndrome

Samples of gastric lymph nodes and the stomachs from 24 pigs selected from herds affected by postweaning multisystemic wasting syndrome (PMWS) and sudden death associated with gastric ulcers were studied. Pigs were selected on the basis of unthriftiness, decreased feed intake, and wasting. The stomachs were opened, inverted, and classified into 0-3 score according the severity of the gross lesions present in pars oesophagica (non-glandulargastric mucosa). Selected samples were processed for paraffin embedding and stained with hematoxylin and eosin. Immunohistochemistry using anti-PCV2 (porcine circovírus type 2) antibody, anti-Helicobacter pylori antibody and a wide-spectrum anti-cytokeratin antibody was performed. Gross changes in pars oesophagea were classified according to the severity of lesions as score 3, 2, and 1 in 8, 6, 5 stomachs respectivelly. Microscopically, hyperplastic lymphoid follicles, lymphohistiocytic inflammatory infiltrates and focci of necrosis in the gastric mucosa were common findings. Large amounts of PCV2 antigen were observed in the cytoplasm and nuclei from intralesional cells and debris from the gastric glandular mucosal zone; however, in the fundus, anti-PCV2 immunostaining was restricted to the surface mucosal cells and foveolar compartment. All gastric lymph nodes were positive for PCV2 antigen. Anti-H. pylori immunostaining was seen in eleven cases, mainly in the antrum, on the mucosal surface and foveolar compartment. The association of the anti-PCV2 immunostaining with the glandular mucus-producing cells suggests a role for PCV2 as an additional factor for the swine ulcer development.

Distribution of collagen types I, III, and IV in gastric tissue of marmosets (Callithrix spp., Callitrichidae: Primates)

Extracellular matrix (ECM) components such as fibrillar collagens play a fundamental role in wound repair and have also been studied in association with the gastric ulcer healing process in gastroenterology. Nevertheless, there have been no studies in the literature to date regarding the description and characterization of ECM components, neither in normal nor in injured gastric tissue of primate species. The objective of this study was to investigate the expression of gastric collagen types I, III, and IV in marmosets (Callithrix sp.). Histological specimens from the stomach of 6 Callithrix jacchus, 12 C. kuhli, and 12 C. geoffroyi were evaluated. The specimens were immunostained with anti-types I and III collagen polyclonal antibodies and anti-type IV collagen monoclonal antibody. Collagen types I and III were detected in the submucosa and lamina propria between the mucosal glands while collagen type IV was detected in the muscularis mucosae, muscular layers, blood vessels, and gastric mucosa between the mucosal glands. It is hoped that these findings can contribute to future studies on the gastric extracellular matrix components in primates and to comparative studies in the area of gastroenterology.

Gas-solid two-phase flow in the riser of circulating fluidized beds: mathematical modelling and numerical simulation

A mathematical model is developed for gas-solids flows in circulating fluidized beds. An Eulerian formulation is followed based on the two-fluids model approach where both the fluid and the particulate phases are treated as a continuum. The physical modelling is discussed, including the formulation of boundary conditions and the description of the numerical methodology. Results of numerical simulation are presented and discussed. The model is validated through comparison to experiment, and simulation is performed to investigate the effects on the flow hydrodynamics of the solids viscosity.

Hydrodynamics Characteristics and Gas-Liquid Mass Transfer in a Three Phase Fluidized Bed Reactor

This paper presents the experimental characterization of hydrodynamics and gas-liquid mass transfer in a three-phase fluidized bed containing polystyrene and nylon particles. The influence of gas and liquid velocities on phase holdups and volumetric gas-liquid mass transfer coefficient was investigated for flow conditions similar to those applied in biotechnological process. The phase holdups were obtained by the pressure profile technique. The volumetric gas-liquid mass transfer coefficient was obtained adjusting the experimental concentration profiles of dissolved oxygen in the liquid phase with the predictions of the axial dispersion model. According to experimental results the liquid holdup increases with the gas velocity, whereas the solid holdup decreases. The gas holdup increases significantly with the increase in gas velocity, and it shows for the three-phase fluidized bed comparable values or larger than those of bubble column. The volumetric gas-liquid mass transfer coefficient increases significantly with an increase in the air velocity for both bubble column and fluidized beds. In addition, in the operational condition of high liquid velocity, the presence of low-density particles in the bed increased the gas-liquid mass transfer, and thus the volumetric mass transfer coefficient values obtained in the fluidized bed were comparable or larger than those of bubble column.

Effect of bacterial lipopolysaccharide on gastric emptying of liquids in rats

The objectives of the present investigation were 1) to study the effect of bacterial lipopolysaccharide (LPS) on rat gastric emptying (GE) and 2) to investigate a possible involvement of the vagus nerve in the gastric action of LPS. Endotoxin from E. coli (strain 055:B5) was administered sc, ip or iv to male Wistar rats (220-280 g body weight) at a maximum dose of 50 µg/kg animal weight. Control animals received an equivalent volume of sterile saline solution. At a given time period after LPS administration, GE was evaluated by measuring gastric retention 10 min after the orogastric infusion of a test meal (2 ml/100 g animal weight), which consisted of 0.9% NaCl plus the marker phenol red (6 mg/dl). One group of animals was subjected to bilateral subdiaphragmatic vagotomy or sham operation 15 days before the test. A significant delay in GE of the test meal was observed 5 h after iv administration of the endotoxin at the dose of 50 µg/kg animal weight. The LPS-induced delay of GE was detected as early as 30 min and up to 8 h after endotoxin administration. The use of different doses of LPS ranging from 5 to 50 µg/kg animal weight showed that the alteration of GE was dose dependent. In addition, vagotomized animals receiving LPS displayed a GE that was not significantly different from that of the sham control group. However, a participation of the vagus nerve in LPS-induced delay in GE could not be clearly demonstrated by these experiments since vagotomy itself induced changes in this gastric parameter. The present study provides a suitable model for identifying the mechanisms underlying the effects of LPS on gastric emptying

Chronic lactose intake modifies the gastric emptying of monosaccharides but not of disaccharides in weanling rats

Ninety-six weanling male Wistar rats were fed for four weeks one of two different chows: a normal rat chow containing 55.5% (w/w) starch (control group, N = 48) or a rat chow in which starch was partially replaced by lactose, in such a way that the experimental group (N = 48) received 35.5% (w/w) starch and 20% (w/w) lactose. The gastric emptying of fluid was then studied by measuring the gastric retention of four test meals containing lactose (5% or 10%, w/v) or glucose + galactose (5% or 10%, w/v). Homogenates of the small intestine were assayed for lactase activity. The gastric retention values were obtained 15 min after orogastric infusion of the liquid meals. The median values for gastric retention of the 5% lactose solutions were 37.7% for the control group and 37.0% for the experimental group (P>0.02). For the 10% lactose solution the median values were 51.2% and 47.9% (P>0.02) for the control and experimental groups, respectively. However, for the 2.5% glucose + 2.5% galactose meal the median gastric retention was lower (P<0.02) in the group fed a lactose-enriched chow (38.5%) than in the control group (41.6%). For the 5% glucose + 5% galactose solution the median values were not statistically different between groups, 65.0% for the control group and 58.8% for the experimental group. The median values of the specific lactase activity in the small intestine homogenate was 0.74 U/g in the control group and 0.91 U/g in the experimental group. These values were not statistically different (P>0.05). These results suggest that the prolonged ingestion of lactose by young adult rats changes the gastric emptying of a solution containing 5% monosaccharides. This adaptation may reflect the desensitization of intestinal nutrient receptors, possibly by an osmotic effect of lactose present in the chow.

Faster gastric emptying of a liquid meal in rats after hypothalamic dorsomedial nucleus lesion

The effects of dorsomedial hypothalamic (DMH) nucleus lesion on body weight, plasma glucose levels, and the gastric emptying of a liquid meal were investigated in male Wistar rats (170-250 g). DMH lesions were produced stereotaxically by delivering a 2.0-mA current for 20 s through nichrome electrodes (0.3-mm tip exposure). In a second set of experiments, the DMH and the ventromedial hypothalamic (VMH) nucleus were lesioned with a 1.0-mA current for 10 s (0.1-mm tip exposure). The medial hypothalamus (MH) was also lesioned separately using a nichrome electrode (0.3-mm tip exposure) with a 2.0-mA current for 20 s. Gastric emptying was measured following the orogastric infusion of a liquid test meal consisting of physiological saline (0.9% NaCl, w/v) plus phenol red dye (6 mg/dl) as a marker. Plasma glucose levels were determined after an 18-h fast before the lesion and on the 7th and 15th postoperative day. Body weight was determined before lesioning and before sacrificing the rats. The DMH-lesioned rats showed a significantly faster (P<0.05) gastric emptying (24.7% gastric retention, N = 11) than control (33.0% gastric retention, N = 8) and sham-lesioned (33.5% gastric retention, N = 12) rats, with a transient hypoglycemia on the 7th postoperative day which returned to normal by the 15th postoperative day. In all cases, weight gain was slower among lesioned rats. Additional experiments using a smaller current to induce lesions confirmed that DMH-lesioned rats had a faster gastric emptying (25.1% gastric retention, N = 7) than control (33.4% gastric retention, N = 17) and VMH-lesioned (34.6% gastric retention, N = 7) rats. MH lesions resulted in an even slower gastric emptying (43.7% gastric retention, N = 7) than in the latter two groups. We conclude that although DMH lesions reduce weight gain, they do not produce consistent changes in plasma glucose levels. These lesions also promote faster gastric emptying of an inert liquid meal, thus suggesting a role for the DMH in the regulation of gastric motility