Effect of γ-Cyclodextrin Inclusion Complex on the Absorption of R-α-Lipoic Acid in Rats

R-α-lipoic acid (RLA) is an endogenous organic acid, and works as a cofactor for mitochondrial enzymes and as a kind of antioxidant. Inclusion complexes of RLA with α-, β- or γ-cyclodextrins (CD) were prepared and orally administered as a suspension to rats. Among them, RLA/γ-CD showed the highest plasma exposure, and its area under the plasma concentration-time curve (AUC) of RLA was 2.2 times higher than that after oral administration of non-inclusion RLA. On the other hand, the AUC after oral administration of non-inclusion RLA and RLA/γ-CD to pylorus-ligated rats did not differ. However, the AUC after intraduodenal administration of RLA/γ-CD was 5.1 times higher than that of non-inclusion RLA, and was almost comparable to the AUC after intraduodenal administration of RLA-Na solution. Furthermore, the AUC after intraduodenal administration of RLA/γ-CD was not affected by biliary ligation or co-administration of an amylase inhibitor. These findings demonstrated that RLA was absorbed from the small intestine effectively when orally administered as a γ-CD inclusion complex, which could be easily dissolved in the lumen of the intestine. In conclusion, γ-CD inclusion complex is an appropriate formulation for supplying RLA as a drug or nutritional supplement with respect to absorption.     

Effect of γ-ray irradiation grafting on the surface property and the bulk structure of M40J fiber

In this study, we aim to improve the surface property and bulk tensile property of M40J graphite fiber by γ-ray co-irradiation treatment of the fiber in epichlorohydrin/acetone mixed solution. The effect of the irradiation treatment was analyzed by X-ray photoelectron spectroscopy, atomic force microscopy, dynamic contact angle test, tensile test, short-beam shear test, scanning electron microscopy, and X-ray diffraction, respectively. The results indicated that the reactive activity, roughness, and interfacial adhesion property of the fiber were improved, and without destroying the bulk structure after the surface irradiation grafting treatment. Mechanical testing results indicated that the tensile strength was decreased slightly; however the tensile module was improved. The γ-ray co-irradiation grafting was an effective method for modifying the physicochemical properties of M40J graphite fiber and improving the interfacial adhesion of its composites.     

Effect of γ-amino Butyric Acid on Limpet Populations: Towards the Future Management and Conservation of Endangered Patellid Species

Many neurotransmitters, such as γ-amino butyric acid (GABA), can act as chemical cues influencing settlement and metamorphosis in benthic marine invertebrates. This effect has been described especially in mollusks, such as mussels, clams, or haliotids. This study describes the first record of the effect of GABA on patellogastropod populations. Special attention was paid to the effect of the compound on recruitment processes. The experiment was carried out using 10 × 10 cm artificial limestone plates that were drilled into intertidal rocks at different inclinations, and periodically treated with a 1 mM GABA solution. A total of five limpet species was considered (four patellid limpet species and the pulmonate Siphonaria pectinata). Each individual recorded on the plates as well as within a 20 × 20 cm quadrant was measured, identified to species level, and its straight-line distance to the application point was registered. Treated surfaces were the first to possess both adults and recruits. Individuals also were found in a higher number around GABA-treated plates than around controls. The results indicated that the compound may not only enhance recruitment, but also might accelerate it. Recruits were located at higher distances from GABA treated plates than from control surfaces. This supports the hypothesis that this is the life history stage most sensitive to the compound. The behavior shown by the individuals belonging to the two endangered patellid species present in the study area (Patella ferruginea and Cymbula nigra) also were analyzed. For the former, the results indicated that the use of GABA may have similar effects on recruitment similar to the presence of adult conspecifics. This is the first report of the effect of GABA on patellid limpet recruitment and population dynamics. Conservational implications of the results are discussed.     

Effect of γ-Radiation on the Dielectric Behaviour of Some Agricultural Wastes

Abstract

Dielectric properties of some agricultural wastes e.g., cotton stalks, Cs, rice straw, Rs and bagasse, B, are studied. The chemical constituents as well as the morphology of these material play a big roll on their dielectric properties. The effect of γ-irradiation on the dielectric properties of these lignocellulosic materials is also investigated. Grafting of these raw materials with acrylamide using γ-irradiation at dose of 20 M rad is also studied. Dielectric properties of these grafted materials and its complexes with Co⁺⁺ is clarified. The mechanism of the interaction of γ-radiation with the investigated samples is also studied.     

Acid attack on hydrated cement — Effect of mineral acids on the degradation process

During acid attack on concrete structural components, a degraded layer develops whose properties as a protective barrier are decisive for durability. ²⁹Si NMR spectroscopy and ²⁷Al NMR spectroscopy were used with XRD to investigate the degraded layer on hardened cement paste exposed to HCl and H₂SO₄. The layer comprises an amorphous silica gel with framework silicates, geminate and single silanol groups in which Si is substituted by Al. Amorphous Al(OH)₃ and Fe(OH)₃ are present. The gel forms by polycondensation and cross-linking of C-A-S-H chains at AlO₄ bridging tetrahedra. In the transition zone between the degraded layer and the undamaged material, portlandite dissolves and Ca is removed from the C-A-S-H phases maintaining their polymer structure at first. With HCl, monosulphate in the transition zone is converted into Friedel's salt and ettringite. With H₂SO₄, gypsum precipitates near the degradation front reducing the thickness of the transition zone and the rate of degradation.     

Effect of Calcium Salts of Glutaric Acid and Pimelic Acid on the Formation of β Crystalline Form in Isotactic Polypropylene

The effect of calcium glutarate (Cagt) and calcium pimelate (Capt) on the formation of β crystalline form in isotactic polypropylene (iPP) after isothermal crystallization at 130°C for 30 min has been investigated. The maximum K_WAXD and K_DSC values were 31.97% and 38.06%, respectively, for iPP doped with 0.2 wt.% Cagt. The maximum values of K_WAXD and K_DSC were 73.60% and 68.44% for iPP doped with 0.3 wt.% and 0.15 wt.% Capt, respectively. The crystal size of iPP doped with Capt is finer than that of iPP doped with Cagt. It is shown that the β nucleation ability of Capt is superior to that of Cagt. The difference in the β nucleation ability between Cagt and Capt is explained by the structural difference of the nucleators with β-iPP.     

The Effect of Sintering Temperature on Microstructure of High Chrome Bricks

The microstructure of high chrome bricks made at dif-ferent sintering temperature are analyzed by SEM. The re-sults indicate that the sintering temperature of high chromebricks has an optimum range, it is not the higher, the ber-ter. The high chrome. bricks made at this sintering temper-ature have the moderate crystal size in the matrix and ofdense structure. The closed bonding structure could be ob-tained between grains and matrix and no crackle occurred.The high chrome bricks with this microstructure have thebest dynamic properties.     

The effect of γ-radiation on the mechanical properties of structural adhesive

The modular satellite concept iBOSS (intelligent Building Blocks for On-Orbit Satellite Servicing and Assembly) enables on-orbit servicing and reconfiguration of satellite systems and has the potential to be a game changer in the space industry. Such building blocks have to withstand all environmental loads in space, e.g.: radiation, vacuum and thermal cycling.The present paper investigates the mechanical properties of the two component epoxy adhesive 3M SW9323 under the environmental effect of radiation. This adhesive is part of the building block's primary structure. Furthermore, adhesive bonding is the sole joining technique used in the whole structure. It is therefore critical to know the influence of ionizing radiation on its load-carrying capacity. For this purpose bulk specimens were manufactured and exposed to γ-radiation, generated by a ⁶⁰Co source. Four different doses were achieved by varying the distance to the source and irradiation time. Afterwards the specimen were tested under tensile loading. Using the digital image correlation technique properties like elastic modulus, shear modulus, tensile strength and elongation at break were determined.The results show that the mechanical properties of the bulk specimen of 3M SW9323 are not influenced by γ-radiation up to a dose of 17.6 kGy. This is explained by the phenomena of crosslinking and chain scission which occur simultaneously and cancel each other out. In addition, Fourier-transform infrared spectroscopy (FTIR) was carried out to investigate if one mechanism is predominant. A slight shift in the spectra indicates the supremacy of chain scission.     

The Protective Effect of Icariin on Mitochondrial Transport and Distribution in Primary Hippocampal Neurons from 3× Tg-AD Mice

Icariin, a pharmacologically active component isolated from the Chinese herb Epimedium, has been shown to improve spatial learning and memory abilities in Alzheimer’s disease (AD) rats through inhibition of Aβ production and tau protein hyperphosphorylation. However, the potential mechanism of icariin-induced protective effects against mitochondrial dysfunctions in AD still remains unclear. In the present study, we investigated the effect of icariin on the modulation of mitochondrial transport and distribution in primary hippocampal cultures from triple-transgenic (3× Tg) AD mice. The results showed that icariin enhanced mitochondrial motility and increased mitochondrial index and mitochondrial length and size in the diseased neurons. Additionally, the expression of the key mitochondrial enzyme, pyruvate dehydrogenase-E1α (PDHE1α), and the post synaptic density protein 95 (PSD95), was preserved in AD neurons after icariin treatment, accompanied by a downregulation of Aβ and phosphorylated tau expression in the corresponding areas. Further study showed that icariin treatment resulted in a decrease in mitochondrial fission protein dynamin-related protein 1 (Drp1) and an increase in fusion protein Mitofusin 2 (Mfn2). These data indicate that icariin can promote mitochondrial transport, protect mitochondria against fragmentation and preserve the expression of mitochondrial and synaptic functional proteins in AD neurons. Thus, icariin may be a potential therapeutic complement for AD and other mitochondrial malfunction-related neuronal degenerative diseases.     

Effect of annealing temperature on structural and optoelectronic properties of γ-CuI thin films prepared by the thermal evaporation method

High quality transparent conducting CuI thin films were deposited at room temperature via thermal evaporation technique followed by post deposition annealing at different temperatures. The samples were characterised by X-ray diffraction (XRD), UV–Vis spectrophotometry, Scanning electron microscopy and I-V measurements. The structural, morphological and optical properties were studied as a function of the annealing temperature from room temperature (RT) to 200 °C. XRD results revealed that the films were polycrystalline with zinc blende structure of cubic phase. Increasing the annealing temperature increased the crystallite size from 33 to 49 nm whilst the dislocation density and lattice strain shifted to lower values. High transmittance of about 70–80% was exhibited by all films in the entire visible spectral range. The as deposited film possesed the lowest resistivity of 3.0×10⁻³ Ω cm.     

Effect of 2-Hydroxypropyl-β-cyclodextrin on Solubility of Sparingly Soluble Drug Derivatives of Anthranilic Acid

Guest-host complex formation of three drug derivatives of anthranilic acid, mefenamic acid, niflumic acid, and flufenamic acid with 2-hydroxypropyl-β-cyclodextrin (2HP-β-CD) in aqueous solutions was investigated using "Phase solubility study" with UV-vis spectrophotometry. Solubility of sparingly soluble drugs has been improved by addition of 2HP-β-CD at two temperatures 298.15 K and 310.15 K and two pH values 2 and 7. The influence of different 2HP-β-CD concentration on solubility of drugs at different pH and temperatures has been investigated. The 2HP-β-CD-drug complex stability constants (K(s)), and dissociations constants (K(d)), as well as the thermodynamic parameters of reaction, i.e., the free energy change (ΔG), the enthalpy change (ΔH) and the entropy change (ΔS), were determined. The experimental data indicated formation of 1:1 inclusion complexes, which were found effective binders increasing the solubility of drugs.     

Effect of Ozone on Viability of Activated Sludge Detected by Oxygen Uptake Rate (OUR) and Adenosine-5′-triphosphate (ATP) Measurement

The current study focused on treatment of phenolic wastewater using an integrated process – dosing of ozone directly to activated sludge. The main goal was to analyze the effect of ozonation on viability of activated sludge in different systems – activated sludge in distilled water and activated sludge in wastewater. Two viability detection methods, oxygen uptake (OUR) rate and adenosine-5'-triphosphate measurement (ATP), were compared. The linear correlation between ATP and OUR measurements in studied range was found to be good (r² = 0.90). In case of ozonation of activated sludge in wastewater, ozone doses up to 42 mgO₃·gMLVSS^?1 did not influence the viability of sludge. In addition, contrary to ozonation of sludge in distilled water, soluble COD was reduced by 15.6% (at ozone dose of 42 mgO₃·gMLVSS^?1).     

Effect of Ag‐promotion on Pd catalysts by XANES

Pd L₃ near‐edge absorption measurements (XANES) were performed on four commercial acetylene hydrogenation catalyst samples, with and without the Ag promoter. The Pd L₃ edge XANES spectra showed that the Ag‐promoted catalysts have relatively weaker absorption peaks and they follow the same order as the relative commercial performances of the four catalysts studied in terms of selectivity in ethylene purification, which indicates that there are increases in the Pd d‐band electron densities due to the addition of Ag. These results provide a reasonable explanation for the observed improvement in selectivity of the Ag‐promoted acetylene hydrogenation catalysts. The Ag L₃ XANES spectra of the supported Pd–Ag catalysts indicate the absence of a white‐line feature which seems to suggest that the charge transferred from Ag to Pd may not be the d‐type. This revised version was published online in July 2006 with corrections to the Cover Date.     

The Effect of Cobalt on the Degradation of Methyl β-D-Gluco-Pyranoside by Oxygen in Aqueous Sodium Hydroxide Solution

Abstract

The effect of Co(II) (0 to 0.25 mW CoSO₄) on the degradation of methyl β-D-glucopyranoside (MBG) at 120°C in 1.25M NaOH with 0.68 MPa oxygen pressure was studied. When the Co(II) was increased from 0.00 to 0.01 to 0.05 mM the MBG half-life decreased from 12 to 6 to 1.5 hours, reflecting approximately a 0.5 order kinetic dependence on cobalt. An oxidation-reduction cycle between Co(II) and Co(III) involving oxidation of Co(II) by oxygen and oxidation of the glucoside by Co(III), hydroxyl radical, or superoxide is proposed for the degradation. At the 0.25 mM Co(II) addition level highly adsorptive Co(OH)₂ formed prior to reaction initiation with oxygen and removed otherwise soluble cobalt from solution. This resulted in lower rates of MBG degradation than obtained even at 0.01 mM Co(II) addition. However, Co(II) solubility could be enhanced if silicate anions or polyols (including MBG) were added to the alklaine medium prior to the Co(II) addition. In reactions initially containing 0.25 mM soluble Co(II), an adsorptive precipitate, presumably CoO(OH), gradually formed after reaction initiation with oxygen. Precipitation of the Co(III) solid coincided with a rapid decline in the rate of MBG degradation. Cobalt had little effect on the products of MBG degradation.     

Synthesis of γ-TiAl by thermal explosion + compaction route: Effect of process parameters and post-combustion treatment on product microstructure

In previous works, we suggested a method for the production of γ-TiAl alloys. This method consists of three main stages: thermal explosion + compaction, thermal treatment, and hot isostatic pressing (HIP). This processing route shows encouraging results in density, microstructure, and mechanical properties. In this work, the effect of some parameters of the thermal explosion + compaction process on the product microstructure was studied. Some interesting results were found and, overall, the significance of a load application schedule was established. Moreover, the combination of the post-combustion processes was studied. In other words, HIP and thermal treatment were carried out in one stage. The most important parameters of the cycles were optimized in order to obtain a fully lamellar microstructure.     

The Effect of Al2O3（Mul.） on Phase Compositions of O′—Sialon Cermics

O′-Sialon Cermics are formed by reaction sintering of silicon nitride and silica with Al2O3(Y2O3) additive,The phase compositions of O′-Sialon Cermics are highly affected by addition of Al2O3( mul.) and are measured by X-ray diffraction techinque.The range of additions which could impaire the stucture of O′-Sialon Cermics is given in this article.