Aboul Ella Hassanien (Abo)

The study of the thermal behavior (DSC) of hydration products in ordinary Portland cement (OPC), as a function of water cement ratios (W/C) (0.2, 0.25, ... 0.4), and the partial substitution of (35 % fly ash), (35 % slag) and (35 % fly ash + 35 % slag) to the OPC system by weight separately was carried out. It was found that the additive materials (pozzlans) increase its durability when added to the OPC. The most important effects in the cement paste microstructure are the changes in pore structure produced by the reduction in the grain size caused by the pozzlanic reactions. The study revealed that the changes in all the thermal parameters depend on the variation of W/C ratios. The systematic changes in the activation energy through all systems occur at (0.3) W/C in the phase (C-H) and (0.35) W/C in the phase (C-S-H). This means that at these ratios of W/C the two phases (C-H) and (C-S-H) further accelerated the process of cement hydration reactions, and at the same time the addition to OPC system may provide enough space for hydration products to be distributed uniformly. © 2005 American Institute of Physics.

The effect of laser irradiation on the electrical properties of Li 0.5+ z Co z Dy x Fe 2.5-2 z - x O 4 ferrite (0.0 = x = 0.2, z = 0.1) has been studied in the temperature range 300 K = T = 750 K at frequencies of 10 kHz-5 MHz, using a LIMO-IR laser diode, at a wavelength of 808 nm. It was found that laser irradiation increases the polarization, the resistivity and the paramagnetic region. As the result of electronic rearrangement and lattice defects, small polorons and clusters were created. The doping of LiCo-Ferrite by Dy 3+ increases both the AC and DC resistance of the investigated material. The variation of the AC and DC resistance with the Dy-content ( x ) obeys the following correlations R ac /100 = 50 x 2 +4 x +0.005 and R dc /1000 = 31 x 2 +0.099 x +0.09, respectively. A peculiar behaviour was obtained for the sample with Dy-content x = 0.075, as the resistance notably decreases. The applicable result is that laser irradiation increases the resistance of LiCo-ferrite by about 17% while its doping by dysprosium at x = 0.15 increases the resistance by about 23%. Its value is nearly stable for the temperature range from 340 to 480 K.

As no physiological mechanism exist for excreting transfusional iron overload in thalassemia, chelation therapy is the mandatory way to remove iron to prevent end organ damage and prolong survival. Desferoxamine (DFO) has been the major iron chelating agent used extensively worldwide for more than three decades for treatment of transfusional iron overload. However compliance has been a major obstacle in achieving an optimal therapeutic results. During the last 20 years the search for an affective oral iron chelators alternatives to Sc. DFO has been intensive. Different compounds have been studied, most of them although effective in animals have shown unacceptable toxicity with the exception of Deferiprone (L1) and ICL670.

The AC conductivity and the dielectric properties were measured as a function of temperature and frequency for the pure and blended chlorinated polyvinyl chloride (CPVC) polymer samples. The DC conductivity was measured in the same range of temperature. The effect of metal ion concentration as well as its ionic radius on the above properties was studied. The measurements of conductivity showed the existence of more than one conduction mechanism. Both DC and AC conductivities increase with increasing the metal ion content. The obtained values of the activation energy indicate the semi conducting behaviour for metal-doped samples. © 2005 IACS.

A standardized willow bark extract (STW 33-I) has been examined to clarify its possible mechanism of action as an anti-inflammatory agent. Various facets have been investigated in two inflammation models: the 6-day air pouch model in rats, representing the acute state and the adjuvant induced arthritis representing the chronic one. Parameters included leukocytic infiltration, levels of cytokines and prostanoids in blood, and effects on cyclo-oxygenase (COX)-1 and/or COX-2 enzymes as well as effects involving free radical production. The effect of the extract was compared at two dose levels with comparable anti-inflammatory doses of acetylsalicylic acid (CAS 50-78-2, ASA) as a non-selective COX inhibitor, and celecoxib (CAS 169590-42-5) as a selective COX-2 inhibitor. On a mg/kg basis, the extract was at least as effective as ASA in reducing inflammatory exudates and in inhibiting leukocytic infiltration as well as in preventing the rise in cytokines, and was more effective than ASA in suppressing leukotrienes, but equally effective in suppressing prostaglandins. On COX-2, STW 33-I was more effective than ASA. The present findings show that STW 33-I significantly raises GSH (reduced glutathione) levels, an effect which helps to limit lipid peroxidation. The extract was more potent than either ASA or celecoxib. Higher doses of the extract also reduced malondialdehyde levels and raised shows definite superiority to either ASA or celecoxib in protecting the body against oxidative stress. It is therefore evident that STW 33-I is at least as active as ASA on all the parameters of inflammatory mediators measured, when both are given on a similar mg/kg dose. Considering, however, that the extract contains only 24% salicin (molecular weight 286.2), while ASA has a molecular weight of 180.3, it follows that on a molar basis of salicin vs salicylate, the extract contains less than a sixth of the amount of salicin as the amount of salicylate in ASA. Thus it appears that STW 33-I with its lower "salicin" content than an equivalent dose of ASA, is at least as active as ASA on the measured parameters, a fact that leads one to speculate that other constituents of the extract contribute to its overall activity. The presence of polyphenols in STW 33-I probably plays a significant role in enhancing its free radical scavenging properties. The fact that STW 33-I was superior to ASA in this respect would suggest that the extract may have a better anti-inflammatory effect than ASA on a weight to weight basis, with possibly less side effects.

A standardized willow bark extract (STW 33-I) has been examined to clarify its possible mechanism of action as an anti-inflammatory agent. Various facets have been investigated in two inflammation models: the 6-day air pouch model in rats, representing the acute state and the adjuvant induced arthritis representing the chronic one. Parameters included leukocytic infiltration, levels of cytokines and prostanoids in blood, and effects on cyclo-oxygenase (COX)-1 and/or COX-2 enzymes as well as effects involving free radical production. The effect of the extract was compared at two dose levels with comparable anti-inflammatory doses of acetylsalicylic acid (CAS 50-78-2, ASA) as a non-selective COX inhibitor, and celecoxib (CAS 169590-42-5) as a selective COX-2 inhibitor. On a mg/kg basis, the extract was at least as effective as ASA in reducing inflammatory exudates and in inhibiting leukocytic infiltration as well as in preventing the rise in cytokines, and was more effective than ASA in suppressing leukotrienes, but equally effective in suppressing prostaglandins. On COX-2, STW 33-I was more effective than ASA. The present findings show that STW 33-I significantly raises GSH (reduced glutathione) levels, an effect which helps to limit lipid peroxidation. The extract was more potent than either ASA or celecoxib. Higher doses of the extract also reduced malondialdehyde levels and raised shows definite superiority to either ASA or celecoxib in protecting the body against oxidative stress. It is therefore evident that STW 33-I is at least as active as ASA on all the parameters of inflammatory mediators measured, when both are given on a similar mg/kg dose. Considering, however, that the extract contains only 24% salicin (molecular weight 286.2), while ASA has a molecular weight of 180.3, it follows that on a molar basis of salicin vs salicylate, the extract contains less than a sixth of the amount of salicin as the amount of salicylate in ASA. Thus it appears that STW 33-I with its lower "salicin" content than an equivalent dose of ASA, is at least as active as ASA on the measured parameters, a fact that leads one to speculate that other constituents of the extract contribute to its overall activity. The presence of polyphenols in STW 33-I probably plays a significant role in enhancing its free radical scavenging properties. The fact that STW 33-I was superior to ASA in this respect would suggest that the extract may have a better anti-inflammatory effect than ASA on a weight to weight basis, with possibly less side effects.

A standardized willow bark extract (STW 33-I) has been examined to clarify its possible mechanism of action as an anti-inflammatory agent. Various facets have been investigated in two inflammation models: the 6-day air pouch model in rats, representing the acute state and the adjuvant induced arthritis representing the chronic one. Parameters included leukocytic infiltration, levels of cytokines and prostanoids in blood, and effects on cyclo-oxygenase (COX)-1 and/or COX-2 enzymes as well as effects involving free radical production. The effect of the extract was compared at two dose levels with comparable anti-inflammatory doses of acetylsalicylic acid (CAS 50-78-2, ASA) as a non-selective COX inhibitor, and celecoxib (CAS 169590-42-5) as a selective COX-2 inhibitor. On a mg/kg basis, the extract was at least as effective as ASA in reducing inflammatory exudates and in inhibiting leukocytic infiltration as well as in preventing the rise in cytokines, and was more effective than ASA in suppressing leukotrienes, but equally effective in suppressing prostaglandins. On COX-2, STW 33-I was more effective than ASA. The present findings show that STW 33-I significantly raises GSH (reduced glutathione) levels, an effect which helps to limit lipid peroxidation. The extract was more potent than either ASA or celecoxib. Higher doses of the extract also reduced malondialdehyde levels and raised shows definite superiority to either ASA or celecoxib in protecting the body against oxidative stress. It is therefore evident that STW 33-I is at least as active as ASA on all the parameters of inflammatory mediators measured, when both are given on a similar mg/kg dose. Considering, however, that the extract contains only 24% salicin (molecular weight 286.2), while ASA has a molecular weight of 180.3, it follows that on a molar basis of salicin vs salicylate, the extract contains less than a sixth of the amount of salicin as the amount of salicylate in ASA. Thus it appears that STW 33-I with its lower "salicin" content than an equivalent dose of ASA, is at least as active as ASA on the measured parameters, a fact that leads one to speculate that other constituents of the extract contribute to its overall activity. The presence of polyphenols in STW 33-I probably plays a significant role in enhancing its free radical scavenging properties. The fact that STW 33-I was superior to ASA in this respect would suggest that the extract may have a better anti-inflammatory effect than ASA on a weight to weight basis, with possibly less side effects.

The burden of kidney disease: Improving global outcomes. Chronic kidney disease (CKD) is a worldwide public health problem with an increasing incidence and prevalence of patients requiring replacement therapy. There is an even higher prevalence of patients in earlier stages of CKD, with adverse outcomes such as kidney failure, cardiovascular disease, and premature death. Patients at earlier stages of CKD can be detected through laboratory testing and their treatment is effective in slowing the progression to kidney failure and reducing cardiovascular events. The evidence-based care of these patients are universal and independent of their geographic location. This paper describes the need to develop a uniform and global public health approach to the worldwide epidemic of CKD. It is to this end that a new initiative Kidney Disease: Improving Global Outcomes' has been established. Some current and future activities of this initiative are described. They include among others modification of the classification of CKD, the development of guidelines on hepatitis C, the organisation of consensus conferences like on Renal Osteodystrophy, and the creation of a website allowing the comparison of the five main English language clinical practice guidelines in kidney disease worldwide.

The optical obsorption, real (ε′) and imaginary parts (ε″) of the dielectric constant, dc conductivity (σ), and I-V characteristics of polyvinyl alcohol (PVA)-gelatin blend were investigated in the temperature range of 290 to 460 K. The identification of the structure and assignments of energy bands were derived in terms of the ligand field theory. The main absorption band at 244 nm, was affected by the gelatin concentration. Two relaxation processes namely αa and αc were obtained at the glass-rubber transition temperature Tg. The first one is due to the rotation of free C=O and NH2 groups inside the amorphous part of PVA while the second one is due to the rotation of the conjugate of C=O groups and semi-crystalline structure on PVA. The calculated values of the activation energies provide us the information about the presence of ionic conduction. At 303 K the conduction mechanism is Ohmic because there is no injection carriers from the electrode contact, while Richardson-Schottky (RS) effect is predominant in the second region at T ≥ 333 K. © 2005 IACS.