Yeast exo-β-glucanases can be used as efficient and readily detectable reporter genes in Saccharomyces cerevisiae

Yeast exo-1,3-β-glucanases are secretable proteins whose function is basically trophic and may also be involved in cell wall glucan hydrolytic processes. Since fluorescein di(β-D -glucopyranoside) is a fluorogenic substrate detectable and quantifiable by flow cytometry, it was used for testing the ability of the EXG1 gene product of Saccharomyces cerevisiae and its homologous gene in Candida albicans to function as reporter genes. These open reading frames were coupled to different promoters in multicopy plasmids, and exoglucanase activity quantified at flow cytometry. Exoglucanases were found to be useful tools for the study of promoter regions in S. cerevisiae. This technique has the advantage over other reporter gene systems—such as β-galactosidase fusions—that it does not require permeabilization of yeast cells and therefore it allows the recovery of viable cells—by sorting—after flow cytometry analysis.     

Antihypertensive agent moxonidine enhances muscle glucose transport in insulin-resistant rats

The sympatholytic antihypertensive agent moxonidine, a centrally acting selective I1-imidazoline receptor modulator (putative agonist), may be beneficial in hypertensive patients with insulin resistance. In the present study, the effects of chronic in vivo moxonidine treatment of obese Zucker rats--a model of severe glucose intolerance, hyperinsulinemia and insulin resistance, and dyslipidemia--on whole-body glucose tolerance, plasma lipids, and insulin-stimulated skeletal muscle glucose transport activity (2-deoxyglucose uptake) were investigated. Moxonidine was administered by gavage for 21 consecutive days at 2, 6, or 10 mg/kg body weight. Body weights in control and moxonidine-treated groups were matched, except at the highest dose, at which final body weight was 17% lower in the moxonidine-treated animals compared with controls. The moxonidine-treated (6 and 10 mg/kg) obese animals had significantly lower fasting plasma levels of insulin (17% and 19%, respectively) and free fatty acids (36% and 28%, respectively), whereas plasma glucose was not altered. During an oral glucose tolerance test, the glucose response (area under the curve) was 47% and 67% lower, respectively, in the two highest moxonidine-treated obese groups. Moreover, glucose transport activity in the isolated epitrochlearis muscle stimulated by a maximally effective insulin dose (13.3 nmol/L) was 39% and 70% greater in the 6 and 10 mg/kg moxonidine-treated groups, respectively (P<.05 for all effects). No significant alterations in muscle glucose transport were elicited by 2 mg/kg moxonidine. These findings indicate that in the severely insulin-resistant and dyslipidemic obese Zucker rat, chronic in vivo treatment with moxonidine can significantly improve, in a dose-dependent manner, whole-body glucose tolerance, possibly as a result of enhanced insulin-stimulated skeletal muscle glucose transport activity and reduced circulating free fatty acids.     

Stress Concentration Factors for a Circular Hole in Curved Beams Under Bending Loads

Abstract: As a contribution to the field of stress concentration studies, the case of circular hole in curved bar elements under bending is hereby studied. Trend values of stress concentration factors (SCF) are presented based on selected variables of the problem for two critical hole locations. The results will help to identify an SCF law for practical use by applying the statistical method of regression analysis. Two approximations obtained by means of computational methods are compared with those obtained by photoelastic experimental method.     

Friction Stir Welding of Ceramic Particle Reinforced Aluminium Based Metal Matrix Composites

The mechanical and microstructural properties of 6061+20% Al₂O_3p and 7005+10% Al₂O_3p aluminium based metal matrix composites joined by friction stir welding were analyzed in the present study. The two materials were welded into the form of sheets of 7 mm thickness after T6 treatment and were tested in tension at room temperature. The microstructure of the joints was observed by optical microscopy and the fracture surfaces were analyzed by employing a scanning electron microscope equipped with field emission gun in order to study the micromechanisms involved during the deformation.     

The feasibility of smoking bans on psychiatric units

Cryptococcal meningitis has a high mortality rate of central nervous infection. The patients usually die of the disease itself, or complications from increased intracranial pressure. Early diagnosis and treatment, including surgical drainage, will improve the results. In this series, twenty-one patients with high intracranial pressure (ICP > 300 mmH2 O) are presented. Fourteen received implantation of Ommaya reservoir to aspirate cerebrospinal fluid (CSF) for relief of symptoms of ICP. Meanwhile 4 of these 14 patients also received intraventricular injection of amphotericin B because of poor response to systemic drugs. Another seven patient received systemic drug therapy only. Survival during therapy occurred in 11 of 14 patients in the surgical group, compared with only 1 of 7 patients treated by drug therapy alone (P = 0.019). In the 14 patients who received implantation of an Ommaya reservoir, there was one complication of CSF leakage when the reservoir ruptured because of repeated aspiration. For patients with cryptococcal meningitis with high ICP, early implantation of an Ommaya reservoir will improve the survival rate.     

Properties of paper coated with kaolin: The influence of the rheological modifier

The first part of this paper analyses the influence of the molecular weight and concentration of carboxymethyl cellulose (CMC) and of kaolin concentration on rheology of the coating colours and on paper properties coated with ultra lightweight coatings (ULWC). In the second part, relationships between the rheological characteristics of the coating colour formulations and coated paper surface quality was also studied.New indexes on paper roughness at micro-scale are presented (RZI and SRI). In general, they show good correlation with sheet gloss. A new gloss index (SGI) is presented, accounting for the contribution of gloss from machine direction (MD) and cross direction (CD). Porosimetry was used to access microstructural characteristics in order to correlate them with light scattering and gloss properties. The former property is closely related to Hg intrusion volume of the coated layer while gloss is related to surface porosity with pore diameters in the range of 7–15 μm as measured by Hg intrusion volume.     

Assessment of Bonelike® graft with a resorbable matrix using an animal model

Synthetic bone grafts have been developed to provide an alternative to autografts and allografts. Bonelike® is a patented synthetic osteoconductive bone graft that mimics the mineral composition of natural bone. In the present preliminary animal studies a user-friendly version of synthetic bone graft Bonelike® have been developed by using a resorbable matrix, Floseal®, as a vehicle and raloxifene hydrochloride as a therapeutic molecule, that is known to decrease osteoclast activity and therefore enhanced bone formation. From histological and scanning electron microscopy evaluations, the use of Bonelike® associated with Floseal® and raloxifene hydrochloride showed that new bone was rapidly apposed on implanted granules and also that the presence of the matrix and therapeutic molecule does not alter the proven highly osteoconductivity properties of Bonelike®. Therefore, this association may be one step-forward for the clinical applications of Bonelike® scaffolds since it is much more easy-to-handle when compared to granular materials.     

Superconductivity in a new quaternary phase with HgSm0.5In0.5Pb2 composition

This work reports a systematic study on the structural and superconducting properties in the Hg-Sm-In-Pb system. It is investigated how In and Sm dopings influence the superconducting properties of the HgPb₂ phase which was recently reported. Results for the HgSm_1 − xPb₂ system show that Sm atoms substitute Hg vacancies in the tetragonal phase which do not affect the onset critical temperature of the HgPb₂ compound. Simultaneous Sm and In doping effects on the properties of the HgPb₂ phase are also studied. Experimental and simulations of X-ray powder diffractograms suggest that the HgSm_1 − xIn_xPb₂ system (0.2 ≤ x ≤ 0.7) has a pseudo-cubic structure with lattice parameters near 4.88 Å. Superconducting properties measurements show that this system has an optimum doping at x ∼ 0.5 with the onset critical temperature close to 6.9 K. This is the highest superconducting critical temperature for the AuCu prototype so far reported.     

Polyamide-6/vegetal fiber composite prepared by extrusion and injection molding

The interest for the use of vegetal fibers as polymers reinforcement has recently increased because of their unique environmental and technological advantages. This work evaluated the use of Curauá fibers in polyamide-6 composites aiming at glass fiber replacement. Fiber content of 20, 30 or 40 wt% and fiber lengths of 0.1 or 10 mm were studied. Fibers were treated with N₂ plasma or washed with NaOH solution, to improve their adhesion to PA-6. Samples with 20 wt% of short or long fibers, with or without pre-treatment, were compounded in two different co-rotating intermeshing twin-screw extruders. These samples were submitted to mechanical and thermal tests. In conclusion, non-dried raw materials improved fiber/matrix interfacial adhesion. Tensile and flexural properties of this composite are better than unfilled, but lower than glass fiber reinforced polyamide-6. However, its impact resistance and heat deflection temperature are similar to the glass fiber reinforced polyamide-6 and its lower density, enable it to replace this latter in specific non-critical applications.     

Genotoxic effect of Physalis angulata L. (Solanaceae) extract on human lymphocytes treated in vitro

Physalis angulata L (Solanaceae) is a medicinal plant from North of Brazil, whose different extracts and infusions are commonly used in the popular medicine for the treatment of malaria, asthma, hepatitis, dermatitis and rheumatism. However, the genotoxic effects of P. angulata on human cells is not well known. The main purpose of the present study was to evaluate the in vitro genotoxic effects of aqueous extract of P. angulata using the comet assay and the micronucleus assay in human lymphocytes provided from 6 healthy donors. Treatments with P. angulata extracts were performed in vitro in order to access the extent of DNA damage. The comet assay has shown that treatments with P. angulata at 0.5, 1.0, 2.0, 3.0 and 6.0 microg/mL in culture medium were genotoxic. Lymphocytes treated with P. angulata at the concentrations of 3.0 and 6.0 microg/mL in culture medium showed a statistically significant increase in the frequency of micronucleus (p<0.05), however, the cytokinesis blocked proliferation index (CBPI) was not decreased after P. angulata treatment. In conclusion, the present work demonstrated the genotoxic effects of P. angulata extract on human lymphocytes in vitro.