Transformation of the recalcitrant pharmaceutical compound carbamazepine by Pleurotus ostreatus: role of cytochrome P450 monooxygenase and manganese peroxidase

Carbamazepine (CBZ) is an environmentally recalcitrant compound highly stable in soil and during wastewater treatment. In this study, we examined the mechanisms by which the white-rot fungus Pleurotus ostreatus metabolizes CBZ in liquid culture using a physiological approach. P. ostreatus PC9 was grown in media known to support different levels of a multiplicity of enzyme systems such as cytochrome P450 (CYP450) and manganese peroxidase (MnP). When both CYP450 and MnP systems were active, 99% of the added CBZ was eliminated from the solution and transformed to 10,11-epoxycarbamazepine. High removal of CBZ was also obtained when either MnP or CYP450 was active. When both CYP450 and MnP were inactivated, only 10 to 30% of the added CBZ was removed. In this latter system, removal of CBZ might be partially attributed to the activity of versatile peroxidase. P. ostreatus was able to eliminate CBZ in liquid culture even when CBZ was added at an environmentally relevant concentration (1 μg L(-1)). On the basis of our study, we suggest that two families of enzymes are involved in the oxidation of CBZ in liquid culture: MnP in a Mn(2+)-dependent or independent manner and CYP450. Our study also highlights the potential of using P. ostreatus for bioremediation systems.     

Sudden gains in prolonged exposure for children and adolescents with posttraumatic stress disorder.

Objective: Our objective was to examine sudden gains during developmentally adjusted prolonged exposure for posttraumatic stress disorder (PTSD) among children and adolescents. We hypothesized that sudden gains would be detected and would be predictive of treatment outcome and follow-up. Method: Sixty-three youngsters (ages 8–17) completed a developmentally adjusted protocol for the treatment of pediatric PTSD (Foa, Chrestman, & Gilboa-Schechtman, 2008). Participants' posttraumatic and depressive symptoms were assessed before each treatment session, as well as at approximately 3 and 12 months after treatment termination. We measured posttraumatic symptoms with the Child PTSD Symptom Scale (Foa, Johnson, Feeny, & Treadwell, 2001) and measured depressive symptoms with the Beck Depression Inventory (Beck, Ward, Mendelson, Mock, & Erbaugh, 1961) and the Children's Depression Inventory (Kovacs, 1981, 1982). Results: Sudden gains were found among 49.2% of participants and constituted 48.6% of the total reduction in posttraumatic symptoms. Compared to individuals who did not experience sudden gains, individuals who experienced sudden gains reported lower levels of posttraumatic symptoms, F(1, 61) = 14.4, p     

High-Temperature Instability of Li- and Ta-Modified (K,Na)NbO3 Piezoceramics

This paper addresses the high-temperature instability of Li- and Ta-modified (K,Na)NbO₃ piezoceramics. The grains with abnormal size evolve out of the fine matrix grains during high-temperature annealing. They are found to be precipitates with a tetragonal tungsten bronze structure, which result from the volatilization and segregation of the alkali metal elements. With the growth of the abnormal grains the composition of the perovskite matrix phase also changes remarkably, as has been suggested by EDX analysis (for Na) and electric measurements (for Li). These variations lead to a large increase in the tetragonal/orthorhombic phase transition temperature and appreciable variations in the dielectric, ferroelectric, and piezoelectric properties of the ceramic samples. Control of the volatilization of the alkali metal elements can efficiently depress the abnormal grain growth and the compositional segregation.     

Raf-1 protein expression in human breast cancer cells

BACKGROUND: The Raf-1 kinase, a 72-kDa cytoplasmic serine-threonine kinase, plays a central role as a second messenger in signal transduction. After ligand binding to a variety of transmembrane tyrosine kinase growth factor receptors including epidermal growth factor (EGF) receptor, the 72-kDa kinase is activated through phosphorylation to a 74-kDa phosphoprotein. The Raf-1 kinase is constitutively activated in many transformed cells either directly, by mutations within its amino-terminus regulatory region, or indirectly, due to overstimulation by autocrine growth factors or activated proximal oncogenes. The role of Raf-1 kinase in breast cancer has not been studied. METHODS: To investigate the role of Raf-1 kinase expression and its activation in breast cancer, we studied three human breast cancer cell lines expressing varying amounts of EGF receptor to determine the level of Raf-1 protein and the proportion expressed in the higher molecular weight form. Effects of serum starvation and stimulation with EGF on the Raf-1 protein were studied in T47D, BT474, and MDA-MB231 cells by precipitation of cell lysates with an anti-Raf-1 antibody followed by immunoblotting. [3H]Thymidine incorporation by these cells after EGF stimulation was also determined as a measure of DNA synthesis. RESULTS: In all three breast cancer cell lines studied, the Raf-1 protein was identified in a 70- and a 74-kDa form. The level of Raf-1 was similar in all three cell lines and appeared unrelated to EGF receptor expression on the cell surface. The majority of the protein was found in the 74-kDa form even after serum starvation. A minor shift from the lower to higher molecular weight form of Raf-1 was apparent in cells treated with EGF, and increased [3H] thymidine incorporation could be demonstrated in two of the cell lines after EGF stimulation. CONCLUSION: Baseline expression of the 74-kDa or activated form of the Raf-1 kinase appeared to be elevated in the breast cancer cells studied, indicating constitutive activation. Further investigation into the role of Raf-1 protein in the pathogenesis of breast cancer is indicated.     

Effect of Silicon Wafer Resistivity on Morphology and Wettability of Silicon Nanowires Arrays

Silicon - Herein, we prepare vertical and single crystalline silicon nanowires (SiNWs) via a one-step metal-assisted chemical etching method in aqueous NH4HF2/AgNO3 solution. The effects of silicon...     

Compositional Inhomogeneity in Li- and Ta-Modified (K, Na)NbO3 Ceramics

Compositional inhomogeneity is examined in Li- and Ta-modified potassium sodium niobate (K,Na)NbO₃ perovskite ceramics. The inhomogeneous distribution of the A-site (K and Na) and B-site (Nb and Ta) cations is found to be correlative. The inhomogeneity could not be eliminated by prolonged high-temperature annealing in samples prepared by direct mixing of alkaline carbonates and Ta and Nb oxides. In contrast, the precursor method, where a (Nb _x Ta_{1− x} )₂O₅ solid solution was first formed, led to a considerably improved compositional homogeneity and appreciably enhanced dielectric, ferroelectric, and piezoelectric properties. Our results suggest that more attention needs to be paid toward controlling the compositional fluctuation of this complex solid solution system.     

Should Altruism,Solidarity, or Reciprocity be Used as Prosocial Appeals? Contrasting Conceptions of Members of the General Public and Medical Professionals Regarding Promoting Organ Donation

Moral appeals to altruism as a means to influence people's prosocial behavior are common, especially in organ donation, but communicators might not consider that conceptions of altruism differ among people, cultures, and scholars. In organ donation employing altruism as the main appeal is contested and some propose using solidarity or reciprocity as alternative prosocial appeals. This qualitative study explored views of people from diverse Israeli groups (29 focus groups) and medical professionals (140) regarding the appropriateness of employing these 3 moral appeals in organ donation. The analysis presents frameworks of contrasting conceptions of altruism that point to potential unintended effects when applying a restrictive conception. It also identifies communication challenges associated with introducing solidarity or reciprocity as prosocial and value‐laden persuasive appeals.     

Fast and robust retrieval of Minkowski sums of rotating convex polyhedra in 3-space

We present a novel method for fast retrieval of exact Minkowski sums of pairs of convex polytopes in R³, where one of the polytopes frequently rotates. The algorithm is based on pre-computing a so-called criticality map, which records the changes in the underlying graph structure of the Minkowski sum of the two polytopes, while one of them rotates. We give tight combinatorial bounds on the complexity of the criticality map when the rotating polytope rotates about one, two, or three axes. The criticality map can be rather large already for rotations about one axis, even for summand polytopes with a moderate number of vertices each. We therefore focus on the restricted case of rotations about a single, though arbitrary, axis.Our work targets applications that require exact collision detection such as motion planning with narrow corridors and assembly maintenance where high accuracy is required. Our implementation handles all degeneracies and produces exact results. It efficiently handles the algebra of exact rotations about an arbitrary axis in R³, and it well balances between preprocessing time and space on the one hand, and query time on the other.We use Cgal arrangements and in particular the support for spherical Gaussian maps to efficiently compute the exact Minkowski sum of two polytopes. We conducted several experiments (i) to verify the correctness of the algorithm and its implementation, and (ii) to compare its efficiency with an alternative (static) exact method. The results are reported.     

Task set switching in schizophrenia.

The authors used a task-switching paradigm to investigate set shifting ability in schizophrenia. This paradigm included 2 choice reaction time (RT) tasks: up–down and right–left. Switching tasks were associated with costs (i.e., longer RT in task-switch trials than in task-repetition trials); patients responded more slowly than controls and suffered greater switching costs, were as efficient as controls in engaging in an upcoming task set, and were faster than controls in disengaging from the previous task set. There were indications that patients quickly forgot what each keypress indicated, making it necessary for them to acquire response meaning information anew in each trial. To test this notion, the authors subsequently tested normal participants in conditions in which response meaning information needed to be acquired anew in each trial. These participants produced a pattern of switching costs resembling that of patients. Results suggest that set switching difficulties in schizophrenia, as exhibited in the present paradigm, reflect poor memory for task context information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)