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This recommendation is devoted to testing the resistance of natural stone and fired-clay brick units against salt crystallization. The procedure was developed by the RILEM TC 271-ASC to evaluate the durability of porous building materials against salt crystallization through a laboratory method that allows for accelerated testing without compromising the reliability of the results. The new procedure is designed to replicate salt damage caused by crystallization near the surface of materials as a result of capillary transport and evaporation. A new approach is proposed that considers the presence of two stages in the salt crystallization test. In the first, the accumulation stage, salts gradually accumulate on or near the surface of the material due to evaporation. In the second, the propagation stage, damage initiates and develops due to changes in moisture content and relative humidity that trigger salt dissolution and crystallization cycles. To achieve this, two types of salt were tested, namely sodium chloride and sodium sulphate, with each salt tested separately. A methodology for assessing the salt-induced damage is proposed, which includes visual and photographical observations and measurement of material loss. The procedure has been preliminarily validated in round robin tests. [ABSTRACT FROM AUTHOR]

Rhodamine 6G-doped TEOS-derived xerogels containing different concentrations of TiO2 nanoparticles with average diameter of about 350 nm were designed to study random laser action. Due to the decantation of TiO2 nanoparticles during the sol–gel process, the obtained xerogels samples exhibits an inhomogeneous TiO2 distribution, with a higher concentration at one of the sample surfaces. By pumping the samples at each of the surfaces at a time with a ps-laser at 532 nm, differences in the emission behavior were observed. The higher concentration of TiO2 in one side of the sample, which occurs during its preparation, was shown to play an important role in the random laser energy threshold and emission spectra, depending on what side of the sample the excitation takes place. The difference in the laser threshold shows that the way scatterers are volumetrically distributed can increase or decrease the pump energy required for laser action. [ABSTRACT FROM AUTHOR]

Fungi of the genus Alternaria are ubiquitous indoor and outdoor airborne agents, and individuals are daily exposed to their spores. Although its importance in human infections and, particularly in respiratory allergies, there are no studies of how Alternaria spp. spores interact with host cells. Our aim was to study the early interaction of Alternaria infectoria spores with macrophages, the first line of immune defense. RAW 264.7 macrophages were infected with A. infectoria conidia, and the internalization and viability of conidia once inside the macrophages were quantified during the first 6 h of interaction. Live cell imaging was used to study the dynamics of this interaction. TNF-α production was quantified by relative gene expression, and the concentration of other cytokines (IL-1α, IL-1β, IL-6, IL-4, IL-10, IL-17, GM-CSF and INF-γ) and a chemokine, MIP-1α, was quantified by ELISA. Conidia were rapidly internalized by macrophages, with approximately half internalized after 30 min of interaction. During the first 6 h of interaction, macrophages retained the ability to mitotically divide while containing internalized conidia. The classical macrophage-activated morphology was absent in macrophages infected with conidia, and TNF-α and other cytokines and chemokines failed to be produced. Thus, macrophages are able to efficiently phagocyte A. infectoria conidia, but, during the first 6 h, no effective antifungal response is triggered, therefore promoting the residence of these fungal conidia inside the macrophages. [ABSTRACT FROM AUTHOR]

Background and aims: The endophytic bacterium Gluconacetobacter diazotrophicus produces exopolysaccharides (EPS) that are required for biofilm formation and colonization of rice seedlings. Here we investigated whether EPS produced by the G. diazotrophicus strain Pal5 protects the bacteria against free radicals. Methods: EPS-mediated protection of Pal5 cells against oxidative damage was evaluated by cell counting and fluorescence microscopy. Rice seedling inoculation studies were performed to investigate the antioxidant activity of EPS during plant colonization. The expression of three bacterial antioxidant genes during plant colonization was also monitored. Results: Free radical activities were reduced in vitro by the addition of Pal5 EPS. An EPS-defective Pal5 mutant was hypersensitive to HO and addition of purified EPS reversed this phenotype. Addition of EPS at the inoculation time increased colonization efficiency by the mutant strain and a similar effect was observed after addition of the antioxidant ascorbic acid. qPCR profiles of sodA, gor, and katE gene expression in the mutant confirmed the role of EPS during the initial plant colonization. Conclusions: Our results indicated that EPS produced by G. diazotrophicus protects the bacterial cells against oxidative stress in vitro and during colonization of rice plants. [ABSTRACT FROM AUTHOR]

The use of silvopastoral systems (SPS) can be a good alternative to reduce the environmental impacts of livestock breeding in Brazil. Despite the advantages offered by public policies, many producers hesitate to use this system. One of the reasons is the lack of information on health and productivity of cattle raised under these conditions. The experiment reported here was designed to compare the behavior of infection by gastrointestinal nematodes and weight gain of beef cattle raised in a SPS and a conventional pasture system. We monitored the number of eggs per gram of feces, the prevalent nematode genus, data on climate, forage availability, weight gain and packed cell volume (PCV) of the animals bred in the two systems. The infection by nematodes was significantly higher in the cattle raised in the SPS (p < 0.05). The coprocultures revealed the presence of nematodes of the genera Haemonchus, Cooperia, Oesophagostomum and Trichostrongylus, in both systems, but the mean infestation rates of Haemonchus and Cooperia were higher in the SPS (p < 0.05). The average of PCV values did not differ between the cattle in the two systems. The individual weight gain and stocking rate in the period did not vary between the systems (p > 0.05). Despite the higher prevalence of nematodes in the SPS, no negative impact was detected on the animals' weight gain and health. The results of this experiment indicate that under the conditions studied, there is no need to alter the parasite management to assure good productive performance of cattle. [ABSTRACT FROM AUTHOR]

Enzymes isolated from extremophiles often exhibit superior performance and potential industrial applications. There are several advantages performing biocatalysis at elevated temperatures, including enhanced reaction rates, increased substrate solubility and decreased risks of contamination. Furthermore, thermophilic enzymes usually exhibit high resistance against many organic solvents and detergents, and are also more resistant to proteolytic attack. In this study, we subcloned and characterized an esterase from the hyperthermophilic archaeon Pyrococcus furiosus (Pf_Est) that exhibits optimal activity around 80 °C using naphthol-derived substrates and p-nitrophenyl palmitate ( pNPP). According to the circular dichroism spectra, the secondary structure of P. furiosus esterase, which is predominantly formed by a β-sheet structure, is very stable, even after incubation at 120°C. We performed SAXS to determine the low-resolution structure of Pf_Est, which is monomeric in solution at 80 °C and has a molecular weight of 28 kDa. The Km and V values for this esterase acting on pNPP were 0.53 mmol/L and 6.5 × 10 U, respectively. Pf_Est was most active in the immiscible solvents and retained more than 50 % in miscible solvents. Moreover, Pf_Est possesses transesterification capacity, presenting better results when isobutanol was used as an acyl acceptor (2.69 ± 0.14 × 10 μmol/min mg) and the highest hydrolytic activity toward olive oil among different types of oils testes in this study. Collectively, these biophysical and catalytic properties are of interest for several biotechnological applications that require harsh conditions, including high temperature and the presence of organic solvents. [ABSTRACT FROM AUTHOR]

Systolic hypertension is associated with cognitive decline in the elderly. Altered blood pressure (BP) variability is a possible mechanism of reduced cognitive performance in elderly hypertensives. We hypothesized that altered beat-to-beat systolic BP variability is associated with reduced global cognitive performance in elderly hypertensive subjects. In exploratory analyses, we also studied the correlation between diverse discrete cognitive domains and indices of systolic BP and heart rate variability. Disproving our initial hypothesis, we have shown that hypertension and low education, but not indices of systolic BP and heart rate variability, were independent predictors of lower global cognitive performance. However, exploratory analyses showed that the systolic BP variability in semi-upright position was an independent predictor of matrix reasoning (B=0.08±.03, P-value=0.005), whereas heart rate variability in semi-upright position was an independent predictor of the executive function score (B=−6.36±2.55, P-value=0.02). We conclude that myogenic vascular and sympathetic modulation of systolic BP do not contribute to reduced global cognitive performance in treated hypertensive subjects. Nevertheless, our results suggest that both systolic BP and heart rate variability might be associated with modulation of frontal lobe cognitive domains, such as executive function and matrix reasoning. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the influence of adding Lactobacillus acidophilus to a triple regimen for Helicobacter pylori eradication in untreated patients with peptic ulcers or ulcer-scars. This was a pre-randomized, single-blind, interventional, treatment-efficacy study with active controls and parallel-assignment, set in Coimbra, Portugal, on 62 consecutive H. pylori-positive untreated adults with peptic ulcers or ulcer-scars, diagnosed by gastroduodenoscopy, with pre-treatment direct Gram-staining and culture of gastric biopsies. The first 31 patients received esomeprazole 20 mg, amoxicillin 1000 mg and clarithromycin 500 mg (EAC), all b.i.d., for 8 days. The remaining 31 added L. acidophilus, 5 × 10 organisms per capsule, 3 + 2 i.d. for 8 days (EACL). The main outcome measure was C urea breath test (UBT), ≥6 weeks after completion of therapy. Successful eradication (UBT-negativity after treatment), was similar in both groups (EAC = 80.6%; EACL = 83.9%, p = 0.740) by both intention-to-treat and per-protocol analysis. The non-eradicated strains were susceptible in vitro to both antibiotics. Adding L. acidophilus to EAC triple therapy did not increase H. pylori eradication rates. Considering the cost and the burden of ingesting five extra capsules daily, supplementing the EAC therapy with L. acidophilus, at this dose, shows no benefit. Further studies with different dosages and duration of treatment, and other probiotics or probiotic combinations are required to improve eradication. [ABSTRACT FROM AUTHOR]

In the present report, we describe the first case of a phaeohyphomycotic brain abscess in a 5-year-old boy with chronic granulomatous disease (CGD) admitted to hospital with seizures. A computed tomography (CT) scan revealed a cerebral abscess and the microbiology study showed a dark, melanin-pigmented fungus, exhibiting only sterile hyphae. This fungus was identified by the amplification and sequencing of the 5.8S RNA gene and of the adjacent internal transcriber spacer domains, ITS1 and ITS2, as Alternaria infectoria. Due to the impossibility of a surgical excision, and although several therapeutic strategies were attempted, the patient died. Limitations in the routine identification procedures and therapeutic options of this emerging opportunistic agent are highlighted in this report. [ABSTRACT FROM AUTHOR]

The effect of azadirachtin was investigated using three different fresh isolates of Trypanosoma cruzi and five different triatomine species which were infected as third-instar larvae. The two T. cruzi strains which originated from sylvatic Triatoma vitticeps showed a high prevalence after the molt to the fifth instar in Panstrongylus megistus and Rhodnius neglectus and a low prevalence in Triatoma infestans and Rhodnius robustus. The third T. cruzi strain originating from a patient in Piauí showed a high prevalence in P. megistus, R. neglectus and T. infestans and a low prevalence in Triatoma sordida. Feeding the infected fifth instars with azadirachtin-supplemented blood (1 μg/ml) resulted 20 days later in some parasite/vector combinations in an increase, in others a decrease or an unchanged number of T. cruzi in comparison to bugs fed with unsupplemented blood. [ABSTRACT FROM AUTHOR]