Effects of 85 dB Noise Exposure on Macro and Trace Element Levels in Plasma and Brain Areas of Rats

In this study, our hypothesis was that workplace noise can alter brain element levels like immobilization and light–dark cycle shift, and we aimed to investigate the effects of workplace noise on element levels of brain areas as well as changes in blood of chronically noise-exposed rats. Twenty-four rats were randomly divided into three groups. The first group was the control. The second group (noise exposed) was subjected to daily 8 h 85 dB workplace noise for 15 days, and the third group (noise exposed plus normal condition) was also subjected to the same noise exposure and then returned to normal condition for 15 days. In noise-exposed group, Na, K, Ca, Mg , Fe, Cu, and Zn levels in plasma significantly increased when compared with controls (p?=?0.03 for Na; p?=?0.005 for K and Mg; p?=?0.002 for Ca and Fe; p?=?0.01 for Cu and Zn). In this group, Fe level of temporal lobe significantly increased (p?=?0.021) while Mg level significantly increased in frontal (p?=?0.021) and temporal (p?=?0.001) lobes when compared with controls. In the noise-exposed plus normal condition group, plasma Na, K, Fe, Cu, and Zn levels were greatly similar to controls. But, plasma Ca and Mg levels significantly decreased when compared with controls (p?=?0.002 and p?=?0.007) and noise-exposed group (p?=?0.002 and p?=?0.001). Fe level of temporal lobe significantly increased when compared with controls (p?=?0.001) and noise exposed group (p?=?0.001). These alterations may be attributed to impaired intake of water and micronutrients or their excretions, emerging by acoustic stress.     

Serotype cycles in cholera dynamics

Interest in understanding strain diversity and its impact on disease dynamics has grown over the past decade. Theoretical disease models of several co-circulating strains indicate that incomplete cross-immunity generates conditions for strain-cycling behaviour at the population level. However, there have been no quantitative analyses of disease time-series that are clear examples of theoretically expected strain cycling. Here, we analyse a 40-year (1966-2005) cholera time-series from Bangladesh to determine whether patterns evident in these data are compatible with serotype-cycling behaviour. A mathematical two-serotype model is capable of explaining the oscillations in case patterns when cross-immunity between the two serotypes, Inaba and Ogawa, is high. Further support that cholera's serotype-cycling arises from population-level immunity patterns is provided by calculations of time-varying effective reproductive rates. These results shed light on historically observed serotype dominance shifts and have important implications for cholera early warning systems.     

Surface plasmon resonance sensing detection of mercury and lead ions based on conducting polymer composite

A new sensing area for a sensor based on surface plasmon resonance (SPR) was fabricated to detect trace amounts of mercury and lead ions. The gold surface used for SPR measurements were modified with polypyrrole-chitosan (PPy-CHI) conducting polymer composite. The polymer layer was deposited on the gold surface by electrodeposition. This optical sensor was used for monitoring toxic metal ions with and without sensitivity enhancement by chitosan in water samples. The higher amounts of resonance angle unit (ΔRU) were obtained for PPy-CHI film due to a specific binding of chitosan with Pb(2+) and Hg(2+) ions. The Pb(2+) ion bind to the polymer films most strongly, and the sensor was more sensitive to Pb(2+) compared to Hg(2+). The concentrations of ions in the parts per million range produced the changes in the SPR angle minimum in the region of 0.03 to 0.07. Data analysis was done by Matlab software using Fresnel formula for multilayer system.     

Improved Photodynamic Efficacy of Zn(II) Phthalocyanines via Glycerol Substitution

Phthalocyanines are excellent photosensitizers for photodynamic therapy as they have strong absorbance in the near infra-red region which is most relevant for in vivo activation in deeper tissular regions. However, most phthalocyanines present two major challenges, ie, a strong tendency to aggregate and low water-solubility, limiting their effective usage clinically. In the present study, we evaluated the potential enhancement capability of glycerol substitution on the photodynamic properties of zinc (II) phthalocyanines (ZnPc). Three glycerol substituted ZnPc, 1–3, (tetra peripherally, tetra non-peripherally and mono iodinated tri non-peripherally respectively) were evaluated in terms of their spectroscopic properties, rate of singlet oxygen generation, partition coefficient (log P), intracellular uptake, photo-induced cytotoxicity and vascular occlusion efficiency. Tetrasulfonated ZnPc (ZnPcS₄) was included as a reference compound. Here, we showed that 1–3 exhibited 10–100 nm red-shifted absorption peaks with higher molar absorptivity, and at least two-fold greater singlet oxygen generation rates compared to ZnPcS₄. Meanwhile, phthalocyanines 1 and 2 showed more hydrophilic log P values than 3 consistent with the number of glycerol attachments but 3 was most readily taken up by cells compared to the rest. Both phthalocyanines 2 and 3 exhibited potent phototoxicity against MCF-7, HCT-116 and HSC-2 cancer cell-lines with IC₅₀ ranging 2.8–3.2 µM and 0.04–0.06 µM respectively, while 1 and ZnPcS₄ (up to 100 µM) failed to yield determinable IC₅₀ values. In terms of vascular occlusion efficiency, phthalocyanine 3 showed better effects than 2 by causing total occlusion of vessels with diameter <70 µm of the chorioallantoic membrane. Meanwhile, no detectable vascular occlusion was observed for ZnPcS₄ with treatment under similar experimental conditions. These findings provide evidence that glycerol substitution, in particular in structures 2 and 3, is able to improve the photodynamic properties of ZnPc.     

Activation of Antioxidant Defenses in Whole Saliva by Psychosocial Stress Is More Manifested in Young Women than in Young Men

Psychosocial stress has been long known to have deleterious effects on health. Nevertheless, an exposure to moderate stressors enhances resilience and promotes health benefits. Male and female organisms differ in many aspects of health and disease. The aim of this study was to investigate antioxidant activity and oxidative damage in saliva in a psychosocial stress paradigm in men and women. Here, we show that an acute stressor of moderate strength augments antioxidant activity and decreases oxidative damage in whole saliva of young people. An examination stress caused a significant increase of catalase activity, accompanied by a decrease of levels of oxidized proteins. Levels of thiobarbituric acid-reacting substances did not increase at stress, indicating that lipid peroxidation was not activated. The stress-induced alterations were more manifested in young women compared to young men. Thus, antioxidant protective mechanisms are more activated by a moderate stressor in young women than in young men.     

Catalytic pyrolysis of Miscanthus x giganteus over activated alumina

The catalytic effects of activated alumina (Al(2)O(3)) on the pyrolysis of Miscanthusxgiganteus, a new energy crop, were investigated. Catalytic pyrolysis experiments carried out under static and nitrogen atmospheres were performed in a fixed-bed reactor. The final pyrolysis temperature was kept constant at 550 degrees C in all of the experiments. The effect of catalyst loading (by weight of feedstock as 10%, 20%, 40%, 60%, 80% and 100%), heating rate (10 degrees C and 50 degrees Cmin(-1)), nitrogen flow rate (50, 100, 150 and 200cm(3)min(-1)) on the pyrolysis conversion and product yields were investigated. The results were compared with those obtained in non-catalytic pyrolysis. Activated alumina catalyst has a strong influence on the Miscanthusxgiganteus pyrolysis product and conversion yield. Furthermore, the catalytic bio-oils obtained from catalytic pyrolysis under static and nitrogen atmospheres were examined using elemental analysis, column chromatography, Fourier transform infrared (FTIR) and nuclear magnetic resonance ((1)H NMR) spectroscopy methods.     

Changes in population dynamics during long-term evolution of sabin type 1 poliovirus in an immunodeficient patient

The evolution of the Sabin strain of type 1 poliovirus in a hypogammaglobulinemia patient for a period of 649 days is described. Twelve poliovirus isolates from sequential stool samples encompassing days 21 to 649 after vaccination with Sabin 1 were characterized in terms of their antigenic properties, virulence in transgenic mice, sensitivity for growth at high temperatures, and differences in nucleotide sequence from the Sabin 1 strain. Poliovirus isolates from the immunodeficient patient evolved gradually toward non-temperature-sensitive and neurovirulent phenotypes, accumulating mutations at key nucleotide positions that correlated with the observed reversion to biological properties typical of wild polioviruses. Analysis of plaque-purified viruses from stool samples revealed complex genetic and evolutionary relationships between the poliovirus strains. The generation of various coevolving genetic lineages incorporating different mutations was observed at early stages of virus excretion. The main driving force for genetic diversity appeared to be the selection of mutations at attenuation sites, particularly in the 5' noncoding region and the VP1 BC loop. Recombination between virus strains from the two main lineages was observed between days 63 and 88. Genetic heterogeneity among plaque-purified viruses at each time point seemed to decrease with time, and only viruses belonging to a unique genotypic lineage were seen from day 105 after vaccination. The relevance of vaccine-derived poliovirus strains for disease surveillance and future polio immunization policies is discussed in the context of the Global Polio Eradication Initiative.     

Phosphatidic acid is a major phospholipid class in reproductive organs of Arabidopsis thaliana

Phospholipids are the crucial components of biological membranes and signal transduction. Among different tissues, flower phospholipids are one of the least characterized features of plant lipidome. Here, we report that floral reproductive organs of Arabidopsis thaliana contain high levels of phosphatidic acid (PA), a known lipid second messenger. By using floral homeotic mutants enriched with specific floral organs, lipidomics study showed increased levels of PA species in ap3-3 mutant with enriched pistils. Accompanied gene expression study for 7 diacylglycerol kinases and 11 PA phosphatases revealed distinct floral organ specificity, suggesting an active phosphorylation/dephosphorylation between PA and diacylglycerol in flowers. Our results suggest that PA is a major phospholipid class in floral reproductive organs of A. thaliana.