Autoassociação de misturas dos Surfactantes Dodecanoato de Sódio (SDoD) e Decanoato de Sódio (SDeC) com o Polímero Hidrofobicamente Modificado Etil(Hidroxietil)Celulose (EHEC)

In this work, the interactions between the non-ionic polymer of ethyl(hydroxyethyl)cellulose (EHEC) and mixed anionic surfactant sodium dodecanoate (SDoD)-sodium decanoate (SDeC) in aqueous media, at pH 9.2 (20 mM borate/NaOH buffer) were investigated by electric conductivity and light transmittance measurements at 25 ºC. The parameters of the surfactant to polymer association processes such as the critical aggregation concentration and saturation of the polymer by surfactants were determined from plots of specific conductivity vs total surfactant concentration, [surfactant]tot = [SDoD] + [SDeC]. Through the results was not observed a specific link of polymer with the surfactant, implying therefore a phenomenon only cooperative association.

The effect of acid hydrolysis on the technological functional properties of pinhão (Araucaria brasiliensis) starch

Technological functional properties of native and acid-thinned pinhão (seeds of Araucária angustifolia, Brazilian pine) starches were evaluated and compared to those of native and acid-thinned corn starches. The starches were hydrolyzed (3.2 mol.L-1 HCl, 44 ºC, 6 hours) and evaluated before and after the hydrolysis reaction in terms of formation, melting point and thermo-reversibility of gel starches, retrogradation (in a 30-day period and measurements every three days), paste freezing and thawing stability (after six freezing and thawing cycles), swelling power, and solubility. The results of light transmittance (%) of pastes of native and acid-thinned pinhão starches was higher (lower tendency to retrogradation) than that obtained for corn starches after similar storage period. Native pinhão starch (NPS) presented lower syneresis than native corn starch (NCS) when submitted to freeze-thaw cycles. The acid hydrolysis increased the syneresis of the two native varieties under storage at 5 ºC and after freezing and thawing cycles. The solubility of NPS was lower than that of native corn starch at 25, 50, and 70 ºC. However, for the acid-thinned pinhão starch (APS), this property was significantly higher (p < 0.05) when compared to that of acid-thinned corn starch (ACS). From the results obtained, it can be said that the acid treatment was efficient in producing a potential fat substitute from pinhão starch variety, but this ability must be further investigated.

Leaf optical properties of two liana species Canavalia parviflora Benth. and Gouania virgata Reissk in different light conditions

Lianas are plants that depend on support to reach some appreciable height, and they represent an important structural component of tropical forests. Although they predominate in clearings and gaps, some species survive in the understory. Changes in irradiance between these environments can affect leaf morphology and absorption of photosynthetic active radiation (PAR). We had examined the effects of different light regimes on leaf optical properties, chlorophyll content, specific leaf area, and leaf surface morphology in young seedlings of Canavalia parviflora Benth. (Fabaceae) and Gouania virgata Reissk (Rhamnaceae). The seedlings were distributed on workbenches covered by different layers of neutral shade netting, thus creating three levels of light intensity corresponding to about 40%, 10% and 1.5% of solar irradiance. Plants growing in full sun were used as a control. Both species exhibited an increase in reflectance in full sun and alterations in leaf morphology. Reduction in irradiance induced an increase in absorptance (decrease in reflectance and transmittance) in C. parviflora leaves in the green due to higher chlorophyll content. In G. virgata the spectral leaf changes were less observable. However, the efficiency of absorption was more pronounced in G. virgata than in C. parviflora leaves under 40%, 10% and 1.5% photon flux density (PFD). The greater efficiency of absorption in G. virgata was due to a larger specific leaf area (SLA) under these conditions. The adjustments in leaf optical properties can aid these species in overall carbon gain under limited light conditions.

The influence of light spectra, UV-A, and growth regulators on the in vitro seed germination of Senecio cineraria DC.

This study was carried out to investigate the effects of light spectra, additional UV-A, and different growth regulators on the in vitro germination of Senecio cineraria DC. Seeds were surface-sterilized and inoculated in MS medium to evaluate the following light spectra: white, white plus UV-A, blue, green, red or darkness. The maximum germinability was obtained using MS0 medium under white light (30%) and MS + 0.3 mg L-1 GA3 in the absence of light (30.5%). S. cineraria seeds were indifferent to light. Blue and green lights inhibited germination. Different concentrations of gibberellic acid (GA3) (0.1; 0.4; 0.6; 0.8; 1.0 and 2.0 mg L-1) and indole-3-acetic acid IAA (0.1; 0.3 and 1.0 mg L-1) were evaluated under white light and darkness. No concentration of GA3 enhanced seed germination percentage under white light. However, when the seeds were maintained in darkness, GA3 improved germination responses in all tested concentrations, except at 1.0 mg L-1. Under white light, these concentrations also increased the germination time and reduced germination rate. Germination rate, under light or darkness, was lower using IAA compared with GA3.

Selection of full-sib families of Panicum maximum Jacq under low light conditions

The silvopastoral system is a viable technological alternative to extensive cattle grazing, however, for it to be successful, forage grass genotypes adapted to reduced light need to be identified. The objective of this study was to select progenies of Panicum maximum tolerant to low light conditions for use in breeding programs and to study the genetic control and performance of some traits associated with shade tolerance. Six full-sib progenies were evaluated in full sun, 50% and 70% of light reduction in pots and subjected to cuttings. Progeny genotypic values ​​(GV) increased with light reduction in relation to plant height (H) and specific leaf area (SLA). The traits total dry mass accumulation (DM) and leaf dry mass accumulation (LDM) had GV higher in 50% shade and intermediate in 70% shade. The GV of tiller number (TIL) and root dry mass accumulation (RDM) decreased with light reduction. The highest positive correlations were obtained for the traits H and RDM with SLA and DM; the highest negative correlations were between TIL and SLA and RDM, and H and LDM. The progenies showed higher tolerance to 50% light reduction and, among them, two stood out and will be used in breeding programs. It was also found that it is not necessary to evaluate some traits under all light conditions. All traits had high broad sense heritability and high genotypic correlation between progenies in all light intensities. There is genetic difference among the progenies regarding the response to different light intensities, which will allow selection for shade tolerance

Influence of light conditions on adult mortality and egg-laying of Triatoma brasiliensis neiva, 1911 (Hemiptera: Reduviidae: Triatominae)

We compared, for Triatoma brasiliensis, the egg-laying process and the mortality of adults under conditions of almost permanent darkness and with normal laboratory luminosity. Mortality did not differ between groups. The egg-laying per vial and per female was significantly greater in the group of normal luminosity. We consider that it is not recommendable to keep the adults of this species under complete darkness. Other biological aspects should be analysed in relation to luminosity.

Treatment of T. cruzi infected human platelet concentrates with aminomethyltrimethyl psoralen (AMT) and ultravioleta (UV-A) light: preliminary results

The present measures adopted to prevent transfusion-associated Chagas' disease include screening of blood donors. and/or the inactivation of T. cruzi in collected blood using gentian violet (GV) as a trypanocidal agent. In this study, we investigated the efficacy of the combined use of AMT and UV-A in inactirating T. cruzi in infected human platelet cuncentrates. Human platelet concentrates were infected with T. cruzi (2x10/ml) of the Y strain transfered to PL 269 (Fenwal Laboratories) containers and treated with GV (250řg,/ml). and ascorbic acid (1 mg/ml); GV. ascorbic acid and UV-A; GV and UV-A; AMT (40/tG/ml) and ascorbic acid; AMT, ascorbic acid and UV-A; AMT and UV-A; UV-A alone; and untreated (control). All UV-A treated platelet concentrates were exposed to UV-A doses of 24, 92, 184, 276, 368 and 644 kj/m². and the microscopical research of active T. cruzi was performed, using the microhematocrit technique, 1, 6 and 24 hours after each treatment. A high number of active forms of T. cruzi was observed in all condictions, except when GV was used as the trypanocidal agent, providing evidence of the failure of AMT and UV-A in inactivating T cruzi in infected human platelet concentrates.

Nutritional status and specific leaf area of mahogany and tonka bean under two light environments

Studies on nutritional status and leaf traits were carried out in two tropical tree species Swietenia macrophylla King (mahogany) and Dipetryx odorata Aubl. Willd. (tonka bean) planted under contrasting light environments in Presidente Figueiredo-AM, Brazil. Leaves of S. macrophylla and D. odorata were collected in three year-old trees grown under full sunlight (about 2000 µmol m-2 s-1) and natural shade under a closed canopy of Balsa-wood plantation (Ochroma pyramidale Cav. Ex. Lam.Urb) about 260 µmol m-2 s-1. The parameters analysed were leaf area (LA), leaf dry mass (LDM), specific leaf area (SLA) and leaf nutrient contents. It was observed that, S. macrophylla leaves grown under full sunlight showed LA 35% lower than those grown under shade. In D. odorata leaves these differences in LA were not observed. In addition, it was observed that S. macrophylla shade leaves, for LDM, were 50% smaller than sun leaves, while in D. odorata, there differences were not observed. SLA in S. macrophylla presented that sun leaves were three times smaller than those grown under shade. In D. odorata, no differences were observed. Nutrient contents in S. macrophylla, regardless of their light environments, showed higher contents for P and Ca than those found in D. odorata. The N, K, Fe and Mn contents in S. macrophylla leaves decreased under shade. Finally, we suggest that the decreasing in leaf nutrient contents may have a negative influence on leaf growth. The results demonstrated that the tested hypothesis is true for leaf traits, which D. odorata, late-successional species, showed lower plasticity for leaf traits than Swietenia macrophylla, mid-successional species.

Effects of light and temperature on isoprene emission at different leaf developmental stages of eschweilera coriacea in central Amazon

Isoprene emission from plants accounts for about one third of annual global volatile organic compound emissions. The largest source of isoprene for the global atmosphere is the Amazon Basin. This study aimed to identify and quantify the isoprene emission and photosynthesis at different levels of light intensity and leaf temperature, in three phenological phases (young mature leaf, old mature leaf and senescent leaf) of Eschweilera coriacea (Matamatá verdadeira), the species with the widest distribution in the central Amazon. In situ photosynthesis and isoprene emission measurements showed that young mature leaf had the highest rates at all light intensities and leaf temperatures. Additionally, it was observed that isoprene emission capacity (Es) changed considerably over different leaf ages. This suggests that aging leads to a reduction of both leaf photosynthetic activity and isoprene production and emission. The algorithm of Guenther et al. (1999) provided good fits to the data when incident light was varied, however differences among E S of all leaf ages influenced on quantic yield predicted by model. When leaf temperature was varied, algorithm prediction was not satisfactory for temperature higher than ~40 °C; this could be because our data did not show isoprene temperature optimum up to 45 °C. Our results are consistent with the hypothesis of the isoprene functional role in protecting plants from high temperatures and highlight the need to include leaf phenology effects in isoprene emission models.

Desenvolvimento e avaliação das propriedades psicométricas da versão brasileira do Addiction Severity Index 6 (ASI-6) Light

Objetivo Desenvolver e avaliar as propriedades psicométricas de uma versão brasileira reduzida do Addiction Severity Index 6 Light (ASI-6 Light) previamente proposta com base em um estudo de validação dos construtos do instrumento e desenvolver os novos escores de cada área do instrumento baseados na Teoria de Resposta ao Item (TRI). Métodos Foram entrevistados 200 sujeitos, 100 com uso problemático de álcool e outras drogas e 100 sem uso problemático. Foram calculados os escores dos indivíduos com base na TRI. As propriedades psicométricas foram avaliadas pela correlação entre os escores do ASI-6 Light e do Alcohol, Smoking and Substance Involvement Screening Test (ASSIST), padrão-ouro do estudo. Foram avaliados os índices de sensibilidade e especificidade. Resultados Foi encontrada alta correlação entre os escores da área “álcool” do ASI-6 Light e os escores do ASSIST em relação ao álcool (r = 0,79), correlações moderadas em relação ao tabaco (r = 0,47) e cocaína/crack (r = 0,44) e baixa (r = 0,39) em relação à maconha. Ao correlacionarem-se os escores do ASSIST e os escores da área “drogas” do ASI-6 Light, obteve-se alta correlação em relação à cocaína/crack (r = 0,85), correlações moderadas em relação ao tabaco (r = 0,57) e maconha (r = 0,68) e baixa (r = 0,29) em relação ao álcool. A área sob a curva ROC da área “álcool” foi de 0,93 e a da área “drogas” foi de 0,88. Conclusão Boas evidências de validade das áreas “álcool” e “drogas” foram apresentadas. Essa nova versão tornou-se um instrumento de fácil manejo e de rápida aplicação, contendo os itens que melhor avaliam a gravidade de problemas.

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.

Ambulatory Blood Pressure Monitoring: Five Decades of More Light and Less Shadows

Abstract Casual blood pressure measurements have been extensively questioned over the last five decades. A significant percentage of patients have different blood pressure readings when examined in the office or outside it. For this reason, a change in the paradigm of the best manner to assess blood pressure has been observed. The method that has been most widely used is the Ambulatory Blood Pressure Monitoring - ABPM. The method allows recording blood pressure measures in 24 hours and evaluating various parameters such as mean BP, pressure loads, areas under the curve, variations between daytime and nighttime, pulse pressure variability etc. Blood pressure measurements obtained by ABPM are better correlated, for example, with the risks of hypertension. The main indications for ABPM are: suspected white coat hypertension and masked hypertension, evaluation of the efficacy of the antihypertensive therapy in 24 hours, and evaluation of symptoms. There is increasing evidence that the use of ABPM has contributed to the assessment of blood pressure behaviors, establishment of diagnoses, prognosis and the efficacy of antihypertensive therapy. There is no doubt that the study of 24-hour blood pressure behavior and its variations by ABPM has brought more light and less darkness to the field, which justifies the title of this review.