Entrapment of porous and stable concanavalin A–peroxidase complex into hybrid calcium alginate–pectin gel

Ammonium sulfate‐fractionated proteins of turnip (Brassica rapa) were used for the simultaneous purification and immobilization of peroxidase by using crude jack bean extract. The concanavalin A–turnip peroxidase complex retained nearly 70% of the original activity. Calcium alginate–pectin‐entrapped soluble turnip peroxidase and the concanavalin A complex of peroxidase retained 63% and 52% of the original activity, respectively. The concanavalin A–peroxidase complex, the alginate–pectin‐entrapped soluble peroxidase and the alginate–pectin‐entrapped concanavalin A–peroxidase complex showed very high stability against denaturation mediated by heat, pH, urea, organic solvents and detergents. The exposure of soluble and immobilized turnip peroxidase to trypsin resulted in an enhancement of the peroxidase activity. The concanavalin A–peroxidase complex entrapped preparation was markedly more stable as compared with the directly entrapped soluble enzyme preparation. The results suggested that such preparations have great potential in the construction of bioreactors to be used for the remediation of aromatic compounds present in polluted wastewater/industrial effluents. Copyright © 2006 Society of Chemical Industry     

Immunity: Plants as Effective Mediators

In the domain of nutrition, exploring the diet–health linkages is major area of research. The outcomes of such interventions led to widespread acceptance of functional and nutraceutical foods; however, augmenting immunity is a major concern of dietary regimens. Indeed, the immune system is incredible arrangement of specific organs and cells that enabled humans to carry out defense against undesired responses. Its proper functionality is essential to maintain the body homeostasis. Array of plants and their components hold immunomodulating properties. Their possible inclusion in diets could explore new therapeutic avenues to enhanced immunity against diseases. The review intended to highlight the importance of garlic (Allium sativum), green tea (Camellia sinensis), ginger (Zingiber officinale), purple coneflower (Echinacea), black cumin (Nigella sativa), licorice (Glycyrrhiza glabra), Astragalus and St. John's wort (Hypericum perforatum) as natural immune boosters. These plants are bestowed with functional ingredients that may provide protection against various menaces. Modes of their actions include boosting and functioning of immune system, activation and suppression of immune specialized cells, interfering in several pathways that eventually led to improvement in immune responses and defense system. In addition, some of these plants carry free radical scavenging and anti-inflammatory activities that are helpful against cancer insurgence. Nevertheless, interaction between drugs and herbs/botanicals should be well investigated before recommended for their safe use, and such information must be disseminated to the allied stakeholders.     

Hydrogen Balmer-β and Balmer-γ emission profiles in an abnormal glow region of hydrogen plasma

Emission spectroscopy measurements of Balmer-β and Balmer-γ line profiles are carried out to study their line shapes and line intensities as a function of discharge parameters such as fill pressure (3-7 mbar) and input power (200-400 W). A technique based on determining the relative intensities of neutral atomic hydrogen emission lines is used to evaluate the electron temperature, whereas the electron density is extracted from the Stark broadening (FWHM) of the H_β emission profile. It is found that both the emission intensity and the broadening of the Balmer-β and Balmer-γ lines exhibit significant dependence on the fill pressure in the same manner. However, both the emission intensity and broadening of the H_β line exhibit a weak dependence on input power in contrast to the H_γ emission line. Based on optical measurements reported here, plasma discharge parameters can be selected to optimize the electron temperature and density.     

Effect of physical training on exercise-induced hyperkalemia in chronic heart failure. Relation with ventilation and catecholamines

BACKGROUND: The exercise-induced rise in arterial potassium concentration ([K+]a) may contribute to exercise hyperpnea and could play a role in exertional fatigue. This study was designed to determine whether the exercise-induced rise in [K+]a is altered in patients with chronic heart failure (CHF) and whether physical training affects K+ homeostasis. METHODS AND RESULTS: We evaluated 10 subjects with CHF (ejection fraction, 23 +/- 3.9%) and 10 subjects with normal left ventricular function (NLVF) who had undergone previous coronary artery graft surgery (ejection fraction, 63 +/- 8.6%). Subjects performed an incremental cycle ergometer exercise test before and after a physical training or detraining program. Changes in [K+]a and ventilation (VE) during exercise were closely related in both groups. Subjects with CHF did less absolute work and had reduced maximal oxygen consumption (VO2max) compared with subjects with NLVF (P < .01). Exercise-induced rises in [K+]a, VE, norepinephrine, lactate, and heart rate were greater at matched absolute work rates in subjects with CHF than in subjects with NLVF (P < .01). However, when the rise in [K+]a was plotted against percentage of VO2max to match for relative submaximal effort, there were no differences between the two groups. Physical training resulted in reduced exercise-induced hyperkalemia at matched submaximal work rates in both groups (P < .01) despite no associated change in the concentration of arterial catecholamines. At maximal exercise when trained, peak increases in [K+]a were unaltered, but peak concentrations of catecholamines were raised (P < .05). The decrease in VE at submaximal work rates after training was not significant with this incremental exercise protocol, but both groups had an increased peak VE when trained (P < .01). CONCLUSIONS: Exercise-induced rises in [K+]a, catecholamines, and VE are greater at submaximal work rates in subjects with CHF than in subjects with NLVF. Physical training reduces the exercise-induced rise in [K+]a but does not significantly decrease VE during submaximal exercise with this incremental cycle ergometry protocol. The reduction in exercise-induced hyperkalemia after training is not the result of altered concentrations of arterial catecholamines. The pathophysiological significance of the increased exercise-induced hyperkalemia in CHF and the mechanisms of improved K+ homeostasis with training have yet to be established.     

Hydrogenation of carbon to methane in reduced sponge iron,chromium and ferrochromium

Hydrogenation of excess carbon to methane in reduced sponge iron, chromium and ferrochromium under isothermal and temperature-programmed conditions indicates that it is possible to control the residual carbon content of the metallized products which may be an advantage if further processing of the products is contemplated. Hydrogenation starts above 800°C and a shrinking-core kinetic model fits the experimental data. The mean apparent activation energy for the hydrogenation of residual carbon to methane in sponge iron, chromium and ferrochromium is 21 kcal/mole.     

Green synthesis of biodegradable terpolymer modified starch nanocomposite with carbon nanoparticles for food packaging application

As to control the increased rate of environmental pollution there is an urgent need to develop improved biodegradable materials regarding the old polymeric packaging materials. It has been done by the incorporation of carbon nanomaterials to the biodegradable starch terpolymers of acrylic acid, methyl methacrylate (MMA), acrylonitrile (AN), 2-Ethylhexyl acrylate (2-EHA), and Ethyl acrylate (EA). The starch-terpolymers were prepared through the free radical polymerization technique using AA, MMA, AN, 2-EHA, EA as monomers. Two different starch-terpolymers were further mixed with carbon nanoparticles (NPs) to form a biodegradable nanocomposite. The biodegradable starch-grafted terpolymers-carbon nanocomposites (STPC NCs) were characterized through scanning electron microscopy, Fourier-transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimeter, and UV–Visible spectrophotometry. Further, resistivity, electrical conductivity, and biodegradability tests were performed to check its properties for packing materials. The biodegradation of SGCP-composites recorded using the soil burial method was up to 78%. Starch-terpolymers were prepared via free-radical polymerization The biodegradation capability of starch-grafted terpolymers was found to be 78% The decrease in water vapor permeability and solubility proves their utilization as food packaging material     

Electrospun Polyamide Nanofiber-Reinforced Hybrid Syntactic Foams

The potential of polyamide nanofibers towards improving the mechanical properties of syntactic foams is demonstrated. Nylon nanofibers were prepared by electrospinning, and the operating parameters, namely solution concentration and flow rate varied to obtain fibers of requisite dimensions. The fibrous mats were employed for reinforcing cenosphere-epoxy syntactic foams. The introduction of nanofibers (0.25% v/v), when placed perpendicularly to the direction of loading led to a marginal improvement (～7%) in the compressive strength. In comparison, the flexural properties of the reinforced foam was significantly higher, with 75 and 62% enhancement in the flexural strength and elongation, respectively.     

Deposition of bismuth sulfide and aluminum doped bismuth sulfide thin films for photovoltaic applications

Journal of Materials Science: Materials in Electronics - Binary bismuth sulfide (Bi2S3) and ternary aluminum-doped bismuth sulfide (Al@Bi2S3) thin films were prepared by the chemical bath...     

Dense plasma focus ion-based titanium nitride coating on titanium

We report the synthesis of titanium nitride coating on a titanium substrate by utilizing energetic nitrogen ions emitted from a 2.3 kJ dense plasma focus device for 30 focus shots. The number of nitrogen ions transferred to the sample by a single ion pulse of about 140 ns duration in the energy interval (40-600 keV) is about 1.09 × 10¹² with a mean energy per ion of 58 keV. The corresponding energy flux delivered to the titanium surface is estimated to be 6.17 × 10¹⁴ keV cm⁻³ ns⁻¹ leading to a transient temperature rise of the top layer of about 5400 K which helps layer growth. The coating is investigated on the basis of its morphological, compositional and hardness properties. X-ray diffraction analysis of the sample reveals the formation of a nanocrystalline titanium nitride coating having (1 1 1) and (2 0 0) plane reflections with an average crystallite size of 40 nm. The compressive residual stresses in the nitride coating have been evaluated to be 2.80 GPa and 6.81 GPa corresponding to (1 1 1) and (2 0 0) plane orientations. A complete restructuring of the manually polished titanium substrate has been observed with appearance of nano-sized multidimensional granular surface morphologies. The thickness of the nitride coating is about 1 μm, whereas the coating has a nitrogen content of 35.35 at.% and 13.78 ± 3.57 wt.% and a surface hardness of 8.19 GPa.