Preparation and Properties of Carboxymethyl Cellulose (CMC)/Sodium alginate (SA) Blends Induced by Gamma Irradiation

Carboxymethyl Cellulose (CMC)/Sodium alginate (SA) blends have been prepared by casting solution method. The effect of different irradiation doses (2.5, 5, 10, 15, and 20 kGy) of gamma rays on the physical properties of the CMC/SA blend containing different ratios of SA (20, 30, and 40 %) such as gel fraction (%) and swelling (%) of CMC/SA blends were investigated. It was found that the gel fraction increases with increasing irradiation dose up to 20 kGy while the swelling of CMC/SA blend films tends to increase with increasing SA content and reduced with increasing irradiation doses. Mechanical and thermal properties of the blend films were improved when CMC content increased and with increasing irradiation dose up to 20 kGy. Morphology of the blend was examined by SEM, which indicates compatibility between CMC and SA. The blend rich in SA content possessed good antimicrobial activity against Gram +ve Bacteria (Bacillus subtilis).     

Effect of dimethoate on the immune system of female mice

Abstract

The functional status of the immune system of female mice exposed to a single oral dose of dimethoate (16 mg / kg) was evaluated by assessing cell mediated and humoral immune responses, in addition to the effect of dimethoate on spleen and body weights after different time intervals. The data showed that dimethoate caused a time ‐ depended decrease in spleen weights in the absence of a change in body weights. The immunologic effect of dimethoate to female mice produced a dose‐dependent decrease in the number of the rosette forming cells (total and active erythrocyte rosette). The ability of splenocytes to proliferation in response to mitogens; phytohemagglutinin (PHA) for T cell and lipopolysaccharide (LPS) for B cell were significantly decreased at the different times. As compared to control, a significant decrease in serum total immunoglobulins (Ig) and IgM was found, while IgG was non‐significant deceased. Results of this study also revealed that dimethoate caused a significant decrease in the number of plaque forming cell (PFC / 10⁶ splenocytes) in a time dependent manner.     

Aluminum interaction with human brain tau protein phosphorylation by various Kinases

Abstract

Phosphorylation is an indispensable process for energy and signal transduction in biological systems. AlCl₃ at 10 nM to 10 uM range activated in‐vitro [γ‐³²P)ATP phosphorylation of the brain (tau) T protein in both normal human or E.coli expressed T forms; in the presence of the kinases P34, PKP, and PKC. However, higher concentrations of ALCl₃ inhibited the T phosphorylation with P34, PKP, and PKC to a maximum at 1 mM level. AlCl₃ at 100 uM to 500 uM range induced non‐enzymatic phosphorylation of T with γ‐ATP, γ‐GTP, and α‐GTP. AlCl₃ activated histone phosphorylation by P34 in a similar pattern. The hyperphosphorylation of T by Al³⁺ was accompanied by molecular shift and mobility retardation in SDS‐PAGE. This may demonstrate the mechanism of the longterm neurological effect of Al³⁺ in human brain leading to the formation of the neurofibrillary tangles related to Alzeheimer's disease.     

Chemical and biological release of 14C‐bound residues from soil treated with 14C‐p,p'‐DDT

Abstract

¹⁴C‐p,p'‐DDT‐bound residues in soil can be released by treatment with concentrated sulphuric acid at ambient temperatures. Within 6 days, about 70% of the bound residues was released. Bound residues released after 9 months incubation with ¹⁴C‐DDT showed the presence of DDT and DDE only while bound residues released after 18 months, contained in addition 13% DDD.

Release of bound ¹⁴C‐residues also occurs readily following inoculation of the soil‐bound residues with fresh soil or with individual microorganisms. Almost complete release of bound residues was observed after incubation for 45 days. The rate of release was rapid during the first two weeks and decreased thereafter. TLC and HPLC analysis showed that the released residues contained DDE (about 80%) and a smaller amount of DDD. The disappearance of DDT from the released residues may be attributed to its microbiological degradation to DDE and DDD, shortly after its release.     

Effects of cyanobacteria producing microcystins on seed germination and seedling growth of several agricultural plants

The effects of cyanobacteria aqueous extracts containing Microcystin-LR (MC-LR) on the seed germination and growth of Pisum sativum, Lens esculenta, Zea mays and Triticum durum were investigated. Experiments were carried out on a range of doses of the extract (equivalent to 0, 1.6, 2.9, 5.8, 8.7 and 11.6 μ g MC-LR/mL). The results confirm that these plants were sensitive to cell-free extracts of a toxic Microcystis and that germination inhibition was dose dependent. One-way analysis of variance (ANOVA) showed that P. sativum is the most sensitive tested species with a 97% germination rate reduction and L. esculenta was the most resistant. At the 8th day, the exposure to the microcystins (MC) resulted in a significant decrease of plant epicotyls length, roots length and a net inhibition of lateral root formation. It is concluded that MC could affect also terrestrial plants seedling germination and growth. Therefore, the use of water for irrigation contaminated by MC could exert negative biochemical effects on seed and plant metabolism which might influence the agricultural crops.     

APCA Honors Five Individuals and Three Sections In 1988 Awards Program

The aim of this study was to analyze the incidence of fungi in the chapel crypt. The MAS 100 was used to monitor the air pollution. The lowest numbers of fungal colonies were isolated at the entrance to the cemetery (2400 CFU/m3). The outside temperature ranged from 24.5oC to 28.1oC, and relative humidity was between 35.3% and 46.4 %. The highest of fungal colonies from air samples at baseline were isolated inside the crypt when coffin was opened (4820 CFU/m3). The temperature in the crypt at baseline varied between 19.6°C and 25.6°C and humidity was between 50.8% and 60.1%. The number of fungal colonies increased significantly at the end of the study. Ten species of fungi were isolated from air samples inside and outside the chapel, and seven species of fungi were isolated on the surface of the exterior and interior of the chapel. Thirteen types/species of fungus were isolated from air samples collected in the crypt; 15 species of fungi were isolated on the walls, surface of the coffin, bones and other objects. Assessment of fungi in the air samples and different surfaces of the crypt, it revealed very high levels of molds in the air samples.

Implications: Assessment of fungi in the air samples and different surfaces of the crypt revealed high levels of molds in the air samples. Fungal numbers within the crypt exceed recommended limits for occupational exposure. Employees working in the crypts should know about these hazards.     

Physicochemical factors and sources of particulate matter at residential urban environment in Kuala Lumpur

Long-term measurements (2004–2011) of PM₁₀ (particulate matter with an aerodynamic diameter <10 μm) and trace gases (carbon monoxide [CO], ozone [O₃], nitrogen oxide [NO], oxides of nitrogen [NO_x], nitrogen dioxide [NO₂], sulfur dioxide [SO₂], methane [CH₄], nonmethane hydrocarbon [NMHC]) have been conducted to study the effect of physicochemical factors on the PM₁₀ concentration. In addition, this study includes source apportionment of PM₁₀ in Kuala Lumpur urban environment. An advanced principal component analysis (PCA) technique coupled with absolute principal component scores (APCS) and multiple linear regression (MLR) has been applied. The average annual concentration of PM₁₀ for 8 yr is 51.3 ± 25.8 μg m^?3, which exceeds the Recommended Malaysian Air Quality Guideline (RMAQG) and international guideline values. Detail analysis shows the dependency of PM₁₀ on the linear changes of the motor vehicles in use and the amount of biomass burning, particularly from Sumatra, Indonesia, during southwesterly monsoon. The main sources of PM₁₀ identified by PCA-APCS-MLR are traffic combustion (28%), ozone coupled with meteorological factors (20%), and windblown particles (1%). However, the apportionment procedure left 28.0 μg m^?3, that is, 51% of PM₁₀ undetermined.

Implications: Air quality is always a top concern around the globe. Especially in the South Asian regions, measures are not yet sufficient; as revealed in our studies, the concentrations of particulate matters exceed the tolerable limits. Long-term data analysis and characterization of particular matters and their sources will aid the policy makers and the concerned authority to adapt measures and policies according to the circumstances. Additionally, similar intensive studies will give insight about future implications of air quality management.     

A new strategy for determination of hydroxylamine and phenol in water and waste water samples using modified nanosensor

A carbon paste electrode modified with p-chloranil and carbon nanotubes was used for the sensitive and selective voltammetric determination of hydroxylamine (HX) and phenol (PL). The oxidation of HX at the modified electrode was investigated by cyclic voltammetry (CV), chronoamperommetry, and electrochemical impedance spectroscopy. The values of the catalytic rate constant (k), and diffusion coefficient (D) for HX were calculated. Square wave voltammetric peaks current of HX and PL increased linearly with their concentrations at the ranges of 0.1–172.0 and 5.0–512.0 μmol L^?1, respectively. The detection limits for HX and PL were 0.08 and 2.0 μmol L^?1, respectively. The separation of the anodic peak potentials of HX and PL reached to 0.65 V, using square wave voltammetry. The proposed sensor was successfully applied for the determination of HX and PL in water and wastewater samples.     

Simultaneous determination of hydroxylamine and phenol using a nanostructure-based electrochemical sensor

The electrochemical oxidation of hydroxylamine on the surface of a carbon paste electrode modified with carbon nanotubes and 2,7-bis(ferrocenyl ethyl)fluoren-9-one is studied. The electrochemical response characteristics of the modified electrode toward hydroxylamine and phenol were investigated. The results showed an efficient catalytic activity of the electrode for the electro-oxidation of hydroxylamine, which leads to lowering its overpotential. The modified electrode exhibits an efficient electron-mediating behavior together with well-separated oxidation peaks for hydroxylamine and phenol. Also, the modified electrode was used for determination of hydroxylamine and phenol in some real samples.     

Synthesis,Characterization and Application of Biodegradable Crosslinked Carboxymethyl Chitosan/Poly(Ethylene Glycol) Clay Nanocomposites

Crosslinked carboxymethyl chitosan (CMCh)/poly(ethylene glycol) (PEG) nanocomposites were synthesized using terephthaloyl diisothiocyanate as a crosslinking agent, in presence of montmorillonite (MMT), in different weight ratios of the two matrices. Characterization of nanocomposites was performed using different analyses. Swelling behavior was studied in different buffered solutions. It was found that formation of crosslinked CMCh/PEG nanocomposites increased the swell ability. Metal ions adsorption had also been investigated. The results indicated that crosslinked CMCh adsorbs various metal ions much more than non-crosslinked CMCh. Antimicrobial activity was examined against Gram-positive bacteria (S. aureus (RCMB 010027) and S. Pyogens (RCMB 010015), Gram-negative bacteria (E. coli (RCMB 010056), and also against fungi (A. fumigates (RCMBA 02564, G. candidum (RCMB 05096) and C. albicans (RCMB 05035). Data indicated that most of these nanocomposites exhibited good antimicrobial potency. Degradation studies were carried out in simulated body fluid for different time periods in order to find out the degradation index. Results showed that weight loss (%) of most of the nanocomposites increased as a function of incubation time.