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In this work, a way of evaluation of recovery focused on the not assimilated content is presented. On this manner, only the contents that were not assimilated by the student would be applied in the test of recovery. The elaboration of the recovery test is done by each student should solve only the questions associated with the not assimilate contents. The evaluation method of recovery was compared with other methods and it was noticed a decrease in the grade repetition. On the other hand, it was perceived that the main motivation is still the approval and not the recovery of contents. Because when the student reaches the grade necessary for approval, he does not care in recovery the contents. Thus, it is still necessary to think about ways to change the culture that the student brings with himself, where the worry is on the approval and not on the assimilation of contents. [ABSTRACT FROM AUTHOR]

Abstract: The lubrication mechanism of articular cartilage is characterized by an efficient performance. In this work, friction of articular cartilage was evaluated with in-site images of articular surface. The images were captured with the laser light reflected at the interface between a prism and articular cartilage. The attenuation of reflectance was associated with the increase of the contact of collagen network of articular cartilage. The light reflectance and friction coefficient for short sliding presented a significant positive correlation. Friction tests were also carried out for short (30s) and long (300s) preloading times. The results indicate that depletion of fluid film is responsible for the increase of friction and the recovery of the fluid film was observed for the long preloading after the early stage of sliding. [Copyright &y& Elsevier]

The S N2′ reaction of propragyl mesylates with organozinc reagents was dramatically improved in DMSO solvent, and the stereoselective conversion of chiral substrates was successfully achieved using LiCl-free diorganozinc without the loss of optical purity. [ABSTRACT FROM AUTHOR]

The t-Bu-P4 base was found to be an excellent catalyst for activating organozinc reagents and was used to promote the SN2′ reaction of α,β-unsaturated esters bearing a γ-chloride using various organozinc reagents: these reactions proceeded in high yields with excellent chemo-and regioselectivity. [ABSTRACT FROM AUTHOR]

Recent developments have shown that organic-inorganic hybrid molecules have the potential to provide useful tools for analyzing biological systems. In the case of fibrinolysis, which is the phenomenon whereby fibrin is degraded by plasmin that has been converted from plasminogen via tissue plasminogen activator (t-PA) secreted from vascular endothelial cells, we hypothesized that there may be organic-inorganic hybrid molecules that could be used to analyze the mechanisms by which endothelial fibrinolysis is regulated. In our present study, we found that a copper complex – copper diethyldithiocarbamate (Cu10) – reduces t-PA activity in a conditioned medium of cultured human coronary endothelial cells by inhibiting the t-PA synthesis without changing the synthesis of plasminogen activator inhibitor type 1, which is a t-PA inhibitor. Copper sulfate, the Cu10 ligand, and zinc/iron complexes with the same Cu10 ligand, did not exhibit such biological activity. These results indicate that Cu10 has the potential to provide a useful tool for finding alternative pathways that downregulate endothelial t-PA synthesis. [ABSTRACT FROM AUTHOR]

Vascular endothelial cells are in direct contact with blood. Inorganic zinc is thought to be incapable of inducing metallothionein, which protects cells from heavy metal toxicity and oxidative stress, in vascular endothelial cells. Here, we aimed to further characterize the induction of metallothionein in vascular endothelial cells. Our results confirmed that inorganic zinc could not induce metallothionein in vascular endothelial cells. Moreover, ZnSO4 could not activate both the metal response element (MRE) transcription factor 1 (MTF-1)/MRE and Nrf2/antioxidant response element (ARE) pathways and was incapable of inducing metallothionein. In addition, bis(L-cysteinato)zincate(II), a zinc complex that activates the MTF-1/MRE pathway, increased MRE promoter activity but failed to induce metallothionein, suggesting that vascular endothelial metallothionein was not induced only by activation of the MTF-1/MRE pathway. Further analysis of a library of zinc complexes showed that zinc(II) bis(diethyldithiocarbamate) activated the MTF-1/MRE pathway but not the Nrf2/ARE pathway, increased MT-1A, MT-1E, and MT-2A mRNA levels, and induced metallothionein proteins. These data indicated that zinc complexes may be excellent tools to analyze metallothionein induction in vascular endothelial cells. [ABSTRACT FROM AUTHOR]

Metallothionein (MT) plays a central role in cellular defense against heavy metals and oxidative stress. Since the induction of MT requires the activation of metal response element (MRE)- binding transcription factor-1 (MTF-1) by binding of zinc ions, inorganic zinc is regarded as a typical MT inducer. However, in a previous report, we showed that inorganic zinc could not induce MT in vascular endothelial cells. While it is suggested that endothelial MT presents mechanisms different from those of other cell types, these remain unclear. In this study, we investigated whether the induction of endothelial MT expression involves the Nrf2-ARE pathway using copper(II) bis(diethyldithiocarbamate), termed Cu10, using a culture system of bovine aortic endothelial cells. Cu10 induced MT-1/2 protein expression and increased the expression of mRNAs for MT-1A, MT-1E, and MT-2, MT isoforms expressed in the cells. Cu10 activated not only the MTF-1-MRE, but also the Nrf2-ARE pathway. MTF-1 knockdown resulted in the repression of Cu10-induced MT-1 and -2 expression. Cu10-induced MT-1 expression was down-regulated by Nrf2 knockdown. However, MT-2 expression was not affected by Nrf2 knockdown. These results suggest that the expression of endothelial MT is up-regulated by the Nrf2-ARE pathway as well as by the MTF-1-MRE pathway. Moreover, MT-1 regulation mechanisms differ from that of MT-2. Specifically, the present data support the hypothesis that MT-1 participates in the biological defense system, while MT-2 mainly regulates intracellular zinc metabolism. [ABSTRACT FROM AUTHOR]

N-Methylation of amines with methanol proceeds at room temperature in the presence of a silver-loaded titanium dioxide (Ag/TiO2) photocatalyst under UV-vis light irradiation. This method allows facile synthesis/isolation of N-methylamines bearing various functional groups including N-benzyl, N-allyl, N-Boc, hydroxyl, ether, acetal, carboxamide, formamide, and olefin groups. [ABSTRACT FROM AUTHOR]

Abstract  This cross-sectional study examined the following four variables for impact on adolescent bone growth: the degree of impact, and the period, frequency, and daily duration of physical activity. We studied 127 boys and 136 girls between the ages of 12 and 15 years from northern Japan. Bone mineral density (BMD) at the spine and hip were measured using dual X-ray absorptiometry, and histories of participation in sports club activities beginning in first grade of elementary school were obtained through a questionnaire. The time spent participating in sports club activities between fourth and sixth grades during elementary school (E4-E6) was predictive of increased BMD, adjusted for height, weight, onset of pubic hair appearance, calcium intake, and grip strength, with the exception of hip BMD in females. Analysis of the period, frequency, daily duration of sports club activity, and a score of mechanical impact of physical activity (MECHPA) as substitute for time spent during E4–E6 revealed a significant relationship between the period of activity and BMD, with the exception of spine BMD in females. Activities performed two or more times a week during E4-E6 were also associated with an increased BMD at the hip for males and the spine region for females. Thus, the period and frequency of sports club activity, independent of its degree of impact or daily duration, in the age range of 9 to 12 years may be important for bone growth in children and adolescents. [ABSTRACT FROM AUTHOR]

Abstract??Bone disease occurs in the predialysis phase of chronic renal failure (CRF). The aim of this study was to examine how a decrease in renal function affects annual bone mineral density (BMD) changes in predialysis CRF patients and to examine the factors that affect BMD. The BMD of the distal radius in 53 predialysis CRF patients (age, 61.3 ? 10.8 years; serum creatinine 2.7 ? 1.2?mg/dl) was measured by peripheral quantitative computed tomography (pQCT) twice with a 1-year interval. The total BMD of the radius significantly decreased over a year (Pr= 0.375,P2D (r= 0.434,P2D. Of several bone metabolic markers examined, baseline serum osteocalcin was significantly positively correlated with annual BMD changes (r= ?0.276,P2D (? = 0.434) was a significant predictor of decreases in total and trabecular BMD (R2= 0.188,PR2= 0.207,P2D level is the principal factor affecting BMD of the radius, suggesting that supplementation with an active form of vitamin D is of importance for predialysis CRF patients. [ABSTRACT FROM AUTHOR]

A novel type of deprotonative arylation of nucleophiles was conducted using Et3SiH/cat. t-Bu-P4 and the powerful SNAr reactions of aryl fluorides were accomplished using alcohols and malonates as nucleophiles. [ABSTRACT FROM AUTHOR]