Spreading kinetics of water drops on self-assembled monolayers of thiols: significance of inertial effects.

Spreading of 5-15 microL water drops on self-assembled monolayers of 1-hexadecanethiol and 11-mercapto-1-undecanol, both homogeneous and mixed compositions, formed on gold-coated silicon wafers or glass slides was recorded with a high-speed video camera. The time (t) evolution of the drop base diameter (D) during spreading was analyzed by a power law-correlation: D approximately t(n). The n value was found to increase from n = 0.3-0.5 for water drops on hydrophobic surfaces characterized by the advancing water contact angle of thetaA = 94-104 degrees to n = 0.5-0.8 on less hydrophobic surfaces (thetaA = 45-66 degrees ). These experimental values were found to be of similar magnitude as the literature values reported for small drops and bubbles, which spread over a variety of different substrates including water and water-ethanol drops on self-assembled monolayers of alkylsilanes, air bubbles in water on glass, molten metals on solid metals and ceramics, hydrocarbon drops on water, and others. Inertial effects, which are often not accounted for in the analysis of spreading results, appear to have an impact on the spreading kinetics of small drops in at least the first few milliseconds of the spreading phenomenon

Selected sociodemographic and clinical predictors of the clock drawing test performance in Polish community dwelling seniors

Objectives: The clock drawing test (CDT) is a commonly used cognitive screening test. The purpose of this study was to investigate the effect of selected sociodemographic, clinical and lifestyle factors on the CDT performance in the Polish elderly population. Methods: CDT performance was assessed in 399 elderly subjects randomly selected out of all participants of a nationwide study on aging, PolSenior2, who met the inclusion criteria. CDT was scored using the Manos–Wu method. The short version of the Geriatric Depression Scale (15-item GDS) was used as a mood measuring tool. Results: Our study revealed a significant relationship between CDT performance and age. Multivariate regression analysis demonstrated also that interactions between reading newspapers and gender and between playing games and GDS score were independent predictors of an incorrect CDT. Of note, even though years of education were related to the CDT score (0–10) in the correlation analysis, education did not predict the global CDT score in the regression analysis. Conclusions: Advanced age was related to incorrect CDT performance. Engagement in some leisure activities may predict the CDT score, while global CDT performance, as assessed by the Manos–Wu method, is relatively unaffected by education

Effect of Lead (Pb) on Inflammatory Processes in the Brain

That the nervous system is the main target of lead (Pb) has long been considered an established fact until recent evidence has linked the Pb effect on the immune system to the toxic effects of Pb on the nervous system. In this paper, we present recent literature reports on the effect of Pb on the inflammatory processes in the brain, particularly the expression of selected cytokines in the brain (interleukin 6, TGF-β1, interleukin 16, interleukin 18, and interleukin 10); expression and activity of enzymes participating in the inflammatory processes, such as cyclooxygenase 2, caspase 1, nitrogen oxide synthase (NOS 2) and proteases (carboxypeptidases, metalloproteinases and chymotrypsin); and the expression of purine receptors P2X4 and P2X7. A significant role in the development of inflammatory processes in the brain is also played by microglia (residual macrophages in the brain and the spinal cord), which act as the first line of defense in the central nervous system, and astrocytes—Whose most important function is to maintain homeostasis for the proper functioning of neurons. In this paper, we also present evidence that exposure to Pb may result in micro and astrogliosis by triggering TLR4-MyD88-NF-κB signaling cascade and the production of pro-inflammatory cytokines

Lead (Pb) Exposure Enhances Expression of Factors Associated with Inflammation

The human immune system is constantly exposed to xenobiotics and pathogens from the environment. Although the mechanisms underlying their influence have already been at least partially recognized, the effects of some factors, such as lead (Pb), still need to be clarified. The results of many studies indicate that Pb has a negative effect on the immune system, and in our review, we summarize the most recent evidence that Pb can promote inflammatory response. We also discuss possible molecular and biochemical mechanisms of its proinflammatory action, including the influence of Pb on cytokine metabolism (interleukins IL-2, IL-4, IL-8, IL-1b, IL-6), interferon gamma (IFNγ), and tumor necrosis factor alpha (TNF-α); the activity and expression of enzymes involved in the inflammatory process (cyclooxygenases); and the effect on selected acute phase proteins: C-reactive protein (CRP), haptoglobin, and ceruloplasmin. We also discuss the influence of Pb on the immune system cells (T and B lymphocytes, macrophages, Langerhans cells) and the secretion of IgA, IgE, IgG, histamine, and endothelin