A method for predicting basins in the global optimization of nanoclusters with applications to AlxCuy alloys

The problem of obtaining the geometrical configuration of a molecule that minimizes its potential energy is a very complicated one for a series of applications, ranging from determining the structure of biological macromolecules to nanoclusters of atoms. Global optimization tools are available for this task, and many of them are based in performing successive local optimizations, where the starting geometries for these steps are determined by an intelligent algorithm. Here we develop a method to save computing time in the optimization of nanoclusters by predicting if a given minimum has been previously visited during local optimization steps. Our application to Cu-Al nanoalloys indicates that it is possible to save a substantial amount of computational cost. The application also reveals new promising Al_xCu_y clusters and explain their stabilities in terms of the jellium model.

Aqueous extract of Chrysobalanus icaco leaves, in lower doses, prevent fat gain in obese high-fat fed mice

ETHNOPHARMACOLOGICAL RELEVANCE

Due to the rise in obesity, the necessity for resources and treatments that could reduce the morbidity and mortality associated to this pandemia has emerged. The development of new anti-obesity drugs through herbal sources has been increasing in the past decades which are being used not only as medicine but also as food supplements. Previous studies with the aqueous extract of Chrysobalanus icaco L (AECI) have demonstrated activity on lowering blood glucose levels and body weight.

AIM OF THE STUDY

Investigate C. icaco effects in overall adiposity and glycemic homeostasis.

MATERIAL AND METHODS

C57BL/6J mice were randomly assigned to standard chow (SC) or high-fat diet (HFD) and treated with AECI in 0.35mg/mL or 0.7mg/mL concentrations ad libitum. Food intake, feed efficiency, metabolic efficiency, body, fat pads and gastrocnemius weight, adiposity index, serum lipids, fecal lipid excretion, locomotor activity in the open field test and insulin and glucose tolerance tests were analyzed and compared. The major components of the extract were demonstrated through HPLC and its antioxidant activity analyzed through DPPH and lipid peroxidation.

RESULTS

The AECI in the 0.35mg/mL concentration did not affect food intake or body weight. However, it promoted lower adipose tissue gain, TG levels, and fecal lipid excretion, increased locomotor activity and lean mass weight, and normalized insulin sensitivity and glucose tolerance. Moreover, AECI showed the presence of myricetin 3-O-glucuronide, rutin, quercitrin and myricitrin and demonstrated high-antioxidant activity.

CONCLUSIONS

AECI in lower concentrations can prevent fat storage or enhance fat utilization through the increase of locomotor activity. Also, this reinforces its ability to maintain glucose homeostasis through the normalization of insulin sensitivity and glucose tolerance despite the high-fat diet intake. These activities could be associated to the extract's polyphenol content.

Translation and cross-cultural adaptation of the Pregnancy Physical Activity Questionnaire (PPAQ) to the Brazilian population

OBJECTIVE

To evaluate the total activity performed by women with low-risk pregnancy as well as translate and pursue a cross-cultural adaptation of the Pregnancy Physical Activity Questionnaire (PPAQ) to the Brazilian reality.

DESIGN

We conducted a cross-sectional quantitative study including 305 women between 16 and 40 years of age with low-risk pregnancies.

SETTING

The Department of Public Health, State University of Ceará, Fortaleza, Brazil.

METHODS

We applied an adapted version of PPAQ to assess the levels of physical activity and the intensity in the metabolic equivalent task (MET), which could be distinguished as follows: sedentary (< 1.5 METs), light (1.5-3.0 METs), moderate activity (3.0-6.0 METs), and vigorous activity (>6.0 METs). The Kruskal-Wallis test was used to compare energy expenditure (MET) with socio-demographic variables.

RESULTS

More than half of the participants performed activities that were classified as light (51.4%). If we group the activities that were categorized as sedentary and light, this value increases to 74.7%, showing a high prevalence of insufficiently active pregnant women. Lower energy expenditure was observed in the third gestational trimester among pregnant women with lower educational level, single women, and mixed-race women (p < 0.05).

CONCLUSION

There is a prevalence of physical inactivity during the three trimesters of pregnancy. The results validate PPAQ for the Brazilian population to serve as a basis for future public policies focused on combating the health problems of mother-infant pairs.

Treatment of an ECF effluent by combined use of activated sludge and advanced oxidation process

The combined biological and chemical treatments of the cellulose effluents have been studied aiming to promote a more significant degradation of their recalcitrant compounds and to reduce their toxicity, as compared with the isolated treatments. In this work the effluent from acid stages of the ECF bleaching of Eucalyptus urograndis pulp was treated by using separately activated sludge and UV radiation and its combination. The treatment efficiency was evaluated by colour, total phenol, COD, BOD, UV spectroscopy, molar weight distribution and toxicity. The untreated effluent presented 587 +/- 18 CU, 19.3 +/- 0.6 mg.L(-1) of total phenol, 2246 +/- 137 mgO2.L(-1) of COD and 904 +/- 48 mgO2.L(-1) of BOD. It did not show acute toxicity to Escherichia coli, but presented chronic toxicity to Selenastrum capricornutum (EC50 = 25%). The sludge treatment resulted in a colour increasing of 42% and decreasing of total phenol, COD and BOD of 33%, 64% and 92%, respectively. The UV radiation treatment for 120 min resulted in a decrease of colour, total phenol, BOD and COD of 70%, 43%, 62% and 43%, respectively. The combined treatment promoted an expressive decrease for colour and total phenol. The UV absorption indicated a degradation of the aromatic compounds. The biological treatment did not remove chronic toxicity and after UV radiation treatment, a 10 times improving toxicity was noticed.

Mathematical modeling of controlled-release kinetics of herbicides in a dynamic-water-bath system

Release of herbicides from lignin-based formulations follows a diffusion-controlled mechanism. For mathematical modeling of diffusive transport, the conventional approach is to assume sink conditions at both surfaces of polymeric matrix. This boundary condition proved to be inadequate to describe experimental data obtained in a water dynamic bath system. However, satisfactory descriptions for this system were obtained when a stagnant unstirred layer of herbicide solution was used as the boundary condition. The adequacy of the model incorporating this new boundary condition was statistically tested using the Fisher test at a confidence level of 95% and plotting the residual distribution.

Mathematical modeling of controlled-release systems of herbicides using lignins as matrices. A review

The herbicides applied in soils can be easily lost, owing to leaching, volatilization, and bio- and photodegradation. Controlled-release systems using polymeric matrices claim to solve these problems. The movement of the herbicides in the soil is also an important phenomenon to be studied in order to evaluate the loss processes. The development of mathematical models is a relevant requirement for simulation and optimization of such systems. This study reviews mathematical models as an initial step for modeling data obtained for controlled-release systems of herbicides (diuron, 2,4-dichlorophenoxyacetic acid, and ametryn) using sugarcane bagasse lignin as a polymeric matrix. The release kinetic studies were carried out using several acceptor systems including a water bath, soil, and soil-packed columns. Generally, these models take into account phenomena such as unsteady-state mass transfer by diffusion (Fick's law) and convection, consumption by several processes, and partitioning processes, resulting in partial differential equations with respect to time and space variables.

Physiological modifications and increase in state anxiety in volunteers submitted to the Stroop Color-Word Interference Test: A preliminary study

For the experimental evaluation of new drugs with a potential anxiolytic effect, there are animal models that can accurately predict clinical activity. However, because of ethical factors, there are few experimental models that allow a reliable evaluation of the anxiolytic activity of drugs in studies performed with human beings. From among them, the Simulated Public Speaking and Stroop Color-Word Interference Test are notable although they are limited by the need to use subjective evaluation scales. The present study was aimed at making the determination of anxiolytic activity of drugs in normal volunteers less subjective by evaluating physiological as well as psychological alterations in subjects submitted to the anxiogenic situation of the Stroop Color-Word Interference Test. Twenty-four volunteers were submitted to the recorded version of Stroop Color-Word Interference Test, and psychological parameters (state anxiety) and physiological parameters (arterial pressure, heart rate, temperature, skin conductance, and frontal and forearm electromyograms) were evaluated before, during, and after the test. Significant differences in temperature, skin conductance and state anxiety of the volunteers were observed between the test situations. These results indicated that the Stroop Color-Word Interference Test can induce, beyond psychological alterations, some physiological alterations that could be used to make the evaluation of the anxiolytic activity of drugs more objective.

Characterization of residual lignin after SO(2)-catalyzed steam explosion and enzymatic hydrolysis of Eucalyptus viminalis wood chips

The lignin component found in both water insoluble (WI) and water and alkali insoluble (WIA) fractions derived from SO(2)-impregnated steam-exploded eucalyptus chips (SEE) was isolated and characterized. Dioxane lignins with a sugar content lower than 2% (w/w) were obtained after each material was treated with commercial cellulases. The C9 formulas of both SEE-WI and SEE-WIA dioxane lignins were C(9)H(6.83)N(0.04)O(2.24)(OCH(3))(1.21)(OH(aro))(0.56)(OH(ali))(0. 77) and C(9)H(8.65)N(0.29)O(1.97)(OCH(3))(0.90)(OH(aro))(0. 46)(OH(ali))(1.02), respectively. The weight-average molecular weight (M(w)) of the SEE-WI lignin corresponded to 3.85 kDa, whereas the SEE-WIA lignin had an M(w) of 3.66 kDa for the same polydispersity of 2.4. The SEE-WIA lignin was shown to be more thermally stable than the SEE-WI lignin, requiring temperatures in the range of 520 degrees C for complete degradation. FTIR and (1)H NMR analyses of both untreated and peracetylated lignin fractions showed that (a) the alkali insoluble lignin contained a relatively higher degree of substitution in aromatic rings per C9 unit and that (b) alkaline extraction removed lignin fragments containing appreciable amounts of phenolic hydroxyl groups.