Sobre os efeitos vasomotôres exercidos pela agua distilada e pelas soluções anisotonicas de clorêto de sodio

The writer reports experiments done with distilled water and hypotonic and hypertonic salt solutions of definite osmotic concentrations. The experiments were performed according to the Laewen-Trendelenburg technic using the vascular system of the frog's hind legs, and according to the Pissemski-Krawkow method using the capillaries of the rabbit's ear. Both preparations react to distilled water by marked vaso-constriction, the same phenomenon taking place in the case of the hypotonic salt solutions. The lower the concentration pf the hypotonic salt solution the stronger the vaso-constriction obtained. With hypertonic salt solutions was observed a strong but rather transient vaso-dilatation followed by secondary vaso-constriction. The later results were found only in the experiments with the frog's hind legs.

Effect of ecological factors on germination of horse purslane (Trianthema portulacastrum)

Trianthema portulacastrum is a very problematic summer crop weed and a complete crop failure has been observed because of this weed at high density. The effect of different ecological factors on germination of T. portulacastrum seeds collected in two different years (2009 and 2005) was studied in laboratory experiments. An increase in temperature from 25 to 35 ºC increased germination percentage of T. portulacastrum from 65 to 85%, after which germination started to decrease, reducing to 71.25% at 45 ºC. Trianthema portulacastrum had maximum germination with distilled water compared with different salt solutions and drought stress levels. Germination was significantly minimum at salinity and drought stress level of 250 mM and -0.8 MPa, respectively. Emergence of T. portulacastrum was maximum (86.25%) at 100% field capacity level but decreased sharply as field capacity decreased thereafter, and minimum emergence (30%) was recorded at field capacity level of 25%. Germination of T. portulacastrum was lowest at pH 5 and any increase in pH resulted in increased germination. A pH range of 8 to 10 had statistically similar germination. Sowing depth of 6 cm reduced the emergence of T. portulacastrum to zero. Reduction in emergence was recorded with depth increase from zero to 5 cm. Maximum emergence was recorded from soil surface (0 cm). An increase in temperature, salinity, drought, sowing depth (up to 4 cm) and a decrease in field capacity increased time to start germination/emergence, time to 50% germination/emergence and mean germination/emergence time but decreased germination/emergence index. Seeds collected during 2009 gave higher germination than old seeds collected in 2005. This information might contribute to development of effective control of T. portulacastrum.

Mineralocorticoid modulation of central angiotensin-induced neuronal activity, water intake and sodium appetite

Central angiotensin II (AngII) stimulates water and salt solution intake. Pretreatment with low-dose mineralocorticoid (DOCA) enhances this AngII-induced intake of salt solutions (the synergy theory) in Wistar and Sprague Dawley rats but not in Fischer rats. This response is mediated via the AT-1 receptor. Electrophysiological experiments using iontophoretic application of AngII and the AT-1 receptor-specific non-peptide antagonist losartan showed excitation of neurons in the preoptic/medial septum region of urethane-anesthetized male Wistar rats. DOCA pretreatment further enhances this neuronal excitation in response to AngII and reduces the responses to losartan. This generated the hypothesis that DOCA-enhanced AngII-induced neuronal excitation is the neural support for the synergy theory. AT-2 receptors modulate these intake responses depending on sodium in the diet, and diuretic-induced dehydration during pregnancy produces a higher salt intake in the offspring. AngII-induced salt and water intakes were tested in offspring from Sprague Dawley mothers with only 1.8% NaCl to drink in which half were treated with furosemide. The important observations were a) the AT-1 antagonist alone suppressed intakes in offspring from mothers not treated with furosemide, b) both AT-1 and AT-2 antagonists suppressed intakes in offspring from furosemide-treated mothers, and c) combined administration of AT-1 and AT-2 antagonists greatly suppressed water intake in offspring from mothers not treated with furosemide. These results suggest that AT-1 and AT-2 receptors have variable properties (receptor number and/or second messengers). Furthermore, the activity and function of these central AngII receptors depend on the background mineralocorticoid levels. The exact mechanism of this influence, however, remains to be determined.

Drying of sicilian lemon residue: influence of process variables on the evaluation of the dietary fiber produced

In this study, the effect of the process variables of the air-drying of Sicilian lemon residues on some technological properties of the fibers produced was studied. The determination and modeling of desorption isotherms were used to establish the equilibrium moisture content at 60, 75, and 90 °C using the static method with 8 saturated salt solutions. The best fit was obtained with BET and GAB models. The drying process was conducted in a vertical tray dryer and delineated according to a central composite experimental design (2²) using the following as factors: air velocity (0.5, 0.75 and 1 m/s) and temperature (60, 75, and 90 °C), and it presented a good fit to the exponential model (R² > 99.9%). The experimental design responses evaluated were the technological properties of the fibers: water-holding, oil-holding, and swelling capacity. Since these properties were present in high levels, the lemon residues could be used to increase content of fibers in foods resulting in the addition of nutritional benefits for the consumers.

Hydraulic conductivity in response to exchangeable sodium percentage and solution salt concentration

Hydraulic conductivity is determined in laboratory assays to estimate the flow of water in saturated soils. However, the results of this analysis, when using distilled or deionized water, may not correspond to field conditions in soils with high concentrations of soluble salts. This study therefore set out to determine the hydraulic conductivity in laboratory conditions using solutions of different electrical conductivities in six soils representative of the State of Pernambuco, with the exchangeable sodium percentage adjusted in the range of 5-30%. The results showed an increase in hydraulic conductivity with both decreasing exchangeable sodium percentage and increasing electrical conductivity in the solution. The response to the treatments was more pronounced in soils with higher proportion of more active clays. Determination of hydraulic conductivity in laboratory is routinely performed with deionized or distilled water. However, in salt affected soils, these determinations should be carried out using solutions of electrical conductivity different from 0 dS m-1, with values close to those determined in the saturation extracts.

Evaluation of the corrosion behavior of the al-356 alloy in NaCl solutions

Cellular metals are a new class of materials with promising applications and a unique combination of physical, chemical and mechanical properties. The Al-356 alloy is used to manufacture metal foams from NaCl preforms. Despite the usefulness of these materials, their performance may be affected by corrosion due to residual salt. This paper reports the study of the behavior of the Al-356 alloy in chloride solutions by electrochemical techniques in rotating disk electrode. The cathodic reaction of oxygen reduction is the crucial stage of process dissolution of the material, which shows that is the oxygen transport which limits the corrosion process.

Osmotic dehydration of sweet potato (Ipomoea batatas) in ternary solutions

The aim of this work was to evaluate the osmotic dehydration of sweet potato (Ipomoea batatas) using hypertonic sucrose solutions, with or without NaCl, at three different concentrations, at 40 °C. Highest water losses were obtained when the mixture of sucrose and NaCl was used. The addition of NaCl to osmotic solutions increases the driving force of the process and it is verified that the osmotic dehydration process is mainly influenced by changes in NaCl concentration, but the positive effect of the salt-sucrose interaction on soluble solids also determined the decrease of solid gain when solutes were at maximum concentrations. Mass transfer kinetics were modeled according to Peleg, Fick and Page's equations, which presented good fittings of the experimental data. Peleg's equation and Page's model presented the best fitting and showed excellent predictive capacity for water loss and salt gain data. The effective diffusivity determined using Fick's Second Law applied to slice geometry was found to be in the range from 3.82 x 10-11 to 7.46 x 10-11 m²/s for water loss and from 1.18 x 10-10 to 3.38 x 10-11 m²/s for solid gain.

Effect of standard and neutral-pH peritoneal dialysis solutions upon fibroblasts proliferation

Introduction: Continuous exposition of the peritoneal membrane to conventional dialysis solutions is an important risk factor for inducing structural and functional alterations. Objective: To compare in vitro mouse fibroblast NIH-3T3 cell viability after exposition to a neutral pH dialysis solution in comparison to cells exposed to a standard solution. Methods: Experimental study to compare the effects of a conventional standard or a neutral-pH, low-glucose degradation products peritoneal dialysis solution on the viability of exposed fibroblasts in cell culture. Both solutions were tested in all the commercially available glucose concentrations. Cell viability was evaluated with tetrazolium salt colorimetric assay. Results: Fibroblast viability was significantly superior in the neutral pH solution in comparison to control, in all three glucose concentrations (Optical density in nm-means ± SD: 1.5% 0.295 ± 0.047 vs. 0.372 ± 0.042, p < 0.001; 2.3% 0.270 ± 0.036 vs. 0.337 ± 0.051, p < 0.001; 4.25% 0.284 ± 0.037 vs. 0.332 ± 0.032, p < 0.001; control vs. neutral pH respectively, Student t Test). There was no significant difference in cell viability between the three concentrations of glucose when standard solution was used (ANOVA p = 0.218), although cell viability was higher after exposition to neutral pH peritoneal dialysis fluid at 1.5% in comparison to 2.3 and 4.25% glucose concentrations (ANOVA p = 0.008: Bonferroni 1.5% vs. 2.3% p = 0.033, 1.5% vs. 4.25% p = 0.014, 2.3% vs. 4.25% p = 1.00). Conclusion: Cell viability was better in neutral pH dialysis solution, especially in the lower glucose concentration. A more physiological pH and lower glucose degradation products may be responsible for such results.

Ethical dilemmas in scientific publication: pitfalls and solutions for editors

Editors of scientific journals need to be conversant with the mechanisms by which scientific misconduct is amplified by publication practices. This paper provides definitions, ways to document the extent of the problem, and examples of editorial attempts to counter fraud. Fabrication, falsification, duplication, ghost authorship, gift authorship, lack of ethics approval, non-disclosure, 'salami' publication, conflicts of interest, auto-citation, duplicate submission, duplicate publications, and plagiarism are common problems. Editorial misconduct includes failure to observe due process, undue delay in reaching decisions and communicating these to authors, inappropriate review procedures, and confounding a journal's content with its advertising or promotional potential. Editors also can be admonished by their peers for failure to investigate suspected misconduct, failure to retract when indicated, and failure to abide voluntarily by the six main sources of relevant international guidelines on research, its reporting and editorial practice. Editors are in a good position to promulgate reasonable standards of practice, and can start by using consensus guidelines on publication ethics to state explicitly how their journals function. Reviewers, editors, authors and readers all then have a better chance to understand, and abide by, the rules of publishing.

MODELES DES TRANSFERTS RADIATIFS A L'INTERIEUR DES COUVERTS VEGETAUX LES SOLUTIONS ANALYTIQUES

Cette étude décrit la modélisation mathématique des transferts radiatifs en milieu végétal, en focalisant l'attention sur le régime du rayonnement solaire au sein des couverts végétaux homogènes. Le rayonnement solaire est traité en quatre composantes principales: rayonnement primaire et complémentaire, chacune de ces parties étant constituée des composantes directe et diffuse. On a présenté, dans un contexte assez général, les équations différentielles ou les systèmes d'équations différentielles qui gouvernent les différents processus de interaction rayonnement-végétation, et des solutions analytiques sont proposées pour les différentes composantes.

Debranching Solutions in Endografting for Complex Thoracic Aortic Dissections

Background: Conventional surgical repair of thoracic aortic dissections is a challenge due to mortality and morbidity risks. Objectives: We analyzed our experience in hybrid aortic arch repair for complex dissections of the aortic arch. Methods: Between 2009 and 2013, 18 patients (the mean age of 67 ± 8 years-old) underwent hybrid aortic arch repair. The procedural strategy was determined on the individual patient. Results: Thirteen patients had type I repair using trifurcation and another patient with bifurcation graft. Two patients had type II repair with replacement of the ascending aorta. Two patients received extra-anatomic bypass grafting to left carotid artery allowing covering of zone 1. Stent graft deployment rate was 100%. No patients experienced stroke. One patient with total debranching of the aortic arch following an acute dissection of the proximal arch expired 3 months after TEVAR due to heart failure. There were no early to midterm endoleaks. The median follow-up was 20 ± 8 months with patency rate of 100%. Conclusion: Various debranching solutions for different complex scenarios of the aortic arch serve as less invasive procedures than conventional open surgery enabling safe and effective treatment of this highly selected subgroup of patients with complex aortic pathologies.

Impact of Light Salt Substitution for Regular Salt on Blood Pressure of Hypertensive Patients

Background: Studies have shown sodium restriction to have a beneficial effect on blood pressure (BP) of hypertensive patients. Objective: To evaluate the impact of light salt substitution for regular salt on BP of hypertensive patients. Methods: Uncontrolled hypertensive patients of both sexes, 20 to 65 years-old, on stable doses of antihypertensive drugs were randomized into Intervention Group (IG - receiving light salt) and Control Group (CG - receiving regular salt). Systolic BP (SBP) and diastolic BP (DBP) were analyzed by using casual BP measurements and Home Blood Pressure Monitoring (HBPM), and sodium and potassium excretion was assessed on 24-hour urine samples. The patients received 3 g of salt for daily consumption for 4 weeks. Results: The study evaluated 35 patients (65.7% women), 19 allocated to the IG and 16 to the CG. The mean age was 55.5 ± 7.4 years. Most participants had completed the Brazilian middle school (up to the 8th grade; n = 28; 80.0%), had a family income of up to US$ 600 (n = 17; 48.6%) and practiced regular physical activity (n = 19; 54.3%). Two patients (5.7%) were smokers and 40.0% consumed alcohol regularly (n = 14). The IG showed a significant reduction in both SBP and DBP on the casual measurements and HBPM (p < 0.05) and in sodium excretion (p = 0.016). The CG showed a significant reduction only in casual SBP (p = 0.032). Conclusions: The light salt substitution for regular salt significantly reduced BP of hypertensive patients.

Effect of day time on foliar spraying of several levels of nitrogen fertilizer, NPKS solutions and its components, on common bean leaves

An experiment was carried out in order to determine the effect of day time of foliar spraying of several levels of nitrogen fertilizers, N-P-K-S station, and its components on common bean leaves. Results, based on the visual observations, indicated the maximum levels of each fertilizer that did not cause injuries and showed that the foliar spraying early in the morning is the best day time.

Quaternary ammonium salt derivatives of allylphenols with peripheral analgesic effect

Ammonium salt derivatives of natural allylphenols were synthesized with the purpose of obtaining potential peripheral analgesics. These drugs, by virtue of their physicochemical properties, would not be able to cross the blood brain barrier. Their inability to enter into the central nervous system (CNS) should prevent several adverse effects observed with classical opiate analgesics (Ferreira et al., 1984). Eugenol (1) O-methyleugenol (5) and safrole (9) were submitted to nitration, reduction and permethylation, leading to the ammonium salts 4, 8 and 12. Another strategy applied to eugenol (1), consisting in its conversion to a glycidic ether (13), opening the epoxide ring with secondary amines and methylation, led to the ammonium salts 16 and 17. All these ammonium salts showed significant peripheral analgesic action, in modified version of the Randall-Sellito test (Ferreira et al. 1978), at non-lethal doses. The ammonium salt 8 showed an activity comparable to that of methylnalorphinium, the prototype of an ideal peripheral analgesic (Ferreira et al., 1984).