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ZrOxNy monolayer, ZrOxNy/Au bilayer, ZrOxNy/Au/TeO2 trilayer films were investigated for their hydrophilic properties and photocatalytic activities. ZrOxNy and Au layers were prepared by dc reactive magnetron sputtering whereas TeO2 layer was prepared by vapor transport technique. X-ray diffraction revealed the formation of monoclinic ZrO2 phase for ZrOxNy films with low nitrogen content whereas mixed monoclinic and tetragonal ZrO2 phases were formed for ZrOxNy films with higher nitrogen content. The chemical composition of ZrOxNy bottom layer affected the growth of the Au layer. The tetragonal TeO2, in ZrOxNy/Au/TeO2 trilayer, blocked most of ZrO2 and Au crystallographic peaks. The ZrOxNy/Au films are composed of tiny nanoparticles in the range 27–33 nm and the ZrOxNy/Au/TeO2 films have branched-nanowires morphology. ZrOxNy monolayer films are hydrophilic and the hydrophilicity decreases then increases with increasing the nitrogen content in the film. Adding an Au layer, then TeO2 layer over ZrOxNy resulted in a pronounced decrease in water contact angle. After UV-illumination the contact angle of the films became almost zero and the surfaces transformed to super-hydrophilic. Nitrogen doping enhances the degradation rate of ZrOxNy monolayer film. The highest degradation rate was observed for ZrO1.9N0.3/Au/TeO2 trilayer film. The prepared ZrOxNy/Au/TeO2 trilayer films are good candidates for self-cleaning and antifogging applications. [ABSTRACT FROM AUTHOR]

In order to enhance the tribological and corrosion properties of AISI 316 substrate, rf plasma carbonitriding was involved to form a carbonitrided layer on AISI 316 base substrate. The deposition of TiN top layer was executed engaging titanium nitride target in argon plasma atmosphere. All the deposition working parameters were reserved to be constant excepting the deposition period that was altered from 4 to 20 min. The effect of TiN top layer thickness on the structure, tribological and electrochemical characteristics of TiN@AISI 316 CN duplex treatment was explored. It was demonstrated, that the duplex coating enhanced the hardness (max: 1740 HV0.025 for TiN (1325nm)@AISI 316 CN sample) and improved the wear and corrosion resistance. Besides, the coefficient of friction is reduced to 0.12–0.2 for TiN@AISI 316 CN duplex treated samples compared with untreated AISI 316 which recorded a value of 0.47. [ABSTRACT FROM AUTHOR]

New, precise and selective HPLC and UHPLC methods have been upgraded and verified for simultaneous estimation of a quaternary mixture of cephalexin (CPH), sodium benzoate (SB), methylparaben (MP) and propylparaben (PP) in their powder for oral suspension (POS) dosage form and applied to holding time study. The bulk holding time study plays an important role in determination of the maximum allowable periods for holding the bulk material starting from preparation till primary packaging and evaluating the quality of the product during the hold time. The analytes are determined by isocratic chromatography condition using 0.01 M ammonium dihydrogen phosphate (pH 4.5 ± 0.1) : acetonitrile : methanol (60:30:10, v/v) as mobile phase and separated on a reverse-phase C8 column (25 cm × 0.46 cm) with injection volume 20 μL and a flow rate of 1.5 mL/min for RP-HPLC and stationary phase C18 column (5 cm × 0.46 cm, 2.7 μm particle size) with injection volume 0.2 μL and a flow rate of 0.3 mL/min for RP-UHPLC with a detection wavelength at 230 nm. Two ecofriendly spectrophotometric methods are successfully deveoped for resolving spectral over-lap of drugs. Method A: first derivative of ratio spectra (1stDD) spectrophotometric method in which CPH is selected at 322.2 nm, while paraben group and SB determined at 285.1 nm, 313.9 nm and 219 nm, 231 nm respectively. Method B: mean centering of ratio (MCR) spectra method at 247 nm, 279 nm and 241 nm for CPH, paraben group and SB, respectively. The validated methods are efficiently accomplished for the pure, pharmaceutical formulation and mixture with a high correlation coefficient ≥0.9995 and recovery 100 ± 1.0%. The reported methods are described for simultaneous determination of quaternary mixture in one injection with shorter run time at high sensitivity and selectivity. [ABSTRACT FROM AUTHOR]

This investigation deals with the structural and textural properties of the monoclinic zirconium oxide (m-ZrO2) doped with various amounts of germanium. The focus was on the impact of potential changes, that could be induced by the addition of germanium atoms, on the behavior of m-ZrO2 when destined for use as a catalyst. GexZrO2 compounds were synthesized through the interaction between the germanium and zirconium oxide at a temperature of 750°C. To characterize these samples several techniques have been used such as: X-ray diffraction, Raman and FT-IR spectroscopy, N2 adsorption-desorption, UV-Vis spectrophotometer. The acquired results revealed the existence of limitations for the germanium amounts that can be dissolved in ZrO2. These limits have been manifested through a progressive formation of GeO2 along with ZrO2 when the molar ratio Ge/ZrO2 exceeds 0.05. The photocatalytic activities of GexZrO2 were evaluated through the degradation of methyl red; the obtained results have demonstrated that doping would improve the photocatalytic activity of m-ZrO2. This improvement was attributed to narrowing the band gap with increasing the concentration of germanium. [ABSTRACT FROM AUTHOR]

The modified Hehner's test (MHT) was applied to detect the formalin in experimentally contaminated and collected commercial cheeses and fish. The spectrophotometric method was adapted to determine the formalin in cheeses and fish samples. The principle of test modification was a complete homogenization and dilution of the examined cheeses and fish samples. By two methods, the incidences of formalin in the market soft and Ras cheeses samples were 31.66 and 3.33%, respectively. Formalin was not detected in the examined market fish samples by MHT, and its concentration by the spectrophotometric method was less than 1 µg/g. The findings of the study indicated that the results obtained by both MHT and spectrophotometric methods were comparable. The applicability of the MHT in different food matrices might mean it has potential as a standard technique with high sensitivity up to 0.001%. (A): Prepared Ras cheese homogenate; (B): Positive and negative modified Hehner's test in the examined Ras cheese samples with different formalin concentrations; (C): Positive and negative modified Hehner's test in the examined soft cheese samples with different formalin concentrations; (D): Negative modified Hehner's test in the examined fish flesh samples with 0.001% formalin concentration; (E): Positive modified Hehner's test in the examined fish flesh samples with 0.1% formalin concentration; (F): Positive modified Hehner's test in the examined fish wash samples with 0.01% formalin concentration [ABSTRACT FROM AUTHOR]

The optoelectronic characteristics and surface plasmon polaritons (SPPs) of nanostructured CdO/Ag/CdO multilayer films prepared by DC pulsed magnetron sputtering were inspected. The multilayer films were deposited with different Ag metallic interlayer thickness ranging from 2 nm to 20 nm. It was observed that the CdO single-layer has high transmittance and it decreased from 85% to 70% in the visible range as the Ag metallic interlayer thickness increased from 2 nm to 20 nm. The CdO/Ag (20nm)/CdO multilayer film has the lowest transmittance and highest reflection in the NIR. The mobility, charge carrier concentration and the conductivity increased as the Ag metallic interlayer increased. The energy gap decreased from 2.77 eV for CdO single-layer to 2.44 eV for CdO/Ag (20nm)/CdO multilayer film. The CdO/Ag (16nm)/CdO multilayer film recorded the highest figure of merit value of 2.45 × 10-3 Ω-1, which acts as an electrode in optoelectronic applications. The absorption of light was interpreted by the creation of surface plasmon polaritons (SPPs) modes along Ag/CdO interface. It was found that the CdO/Ag/CdO multilayer films could be employed as SPPs nano-waveguide for telecommunication applications at excitation wavelengths of 775 nm and 1550 nm. [ABSTRACT FROM AUTHOR]

ZnO thin films were prepared by chemical vapour transport method in inductively coupled plasma (ICP). The films were synthesized at different substrate positions and various oxygen/argon ratios. X-ray diffraction (XRD) revealed that all the synthesized films at different positions are mixture of hexagonal ZnO and hexagonal Zn phases. The relative peak integrated intensity (RPII) of the ZnO phase is 83.6, 25.3 and 45.3%, for positions 1, 2 and 3, respectively. Morphology of ZnO films was found to be sensitive to substrate position. Flat flakes, bended nanowires (NWs) and nanoparticles morphologies are observed for positions 1, 2 and 3, respectively. The sample synthesized at 1 is stoichiometric, whereas the samples prepared in positions 2 and 3 are sub-stoichiometric. The films prepared at positions 1 and 3 have relatively high transmittance and low reflectance values, whereas the film prepared at position 2 has low transmittance and high reflectance. The ZnO film prepared at position 2 is hydrophobic with water contact angle of 112.2°, which can be used as self-cleaning coating. For ZnO films prepared with various O2 ratios, the RPII was 83.2, 88.0, 96.4 and 100% for films prepared with 10, 20, 30 and 40%, respectively. With increasing O2 ratio, the nanograins became bigger and the stoichiometry improved. The transmittance and optical bandgap increased, whereas the reflectance and refractive index decreased with increase in O2 ratio. The ZnO film synthesized with 30% O2 ratio has the highest figure of merit (FOM) value; thus, this film may be considered as the best ZnO film for transparent conducting coating applications. [ABSTRACT FROM AUTHOR]

The effect of interference on the optoelectronic properties of TiO2/Cu/TiO2 multilayers deposited by DC pulsed magnetron sputtering was scrutinized. The TCT multilayers were arranged with different thicknesses of the Cu metallic interlayer. The outcomes revealed that the band gap energy of TiO2/Cu/TiO2 multilayers decreased with increasing Cu metallic interlayer thickness. The Eg value for TiO2 single layer recorded 3.49 eV and decreased to a value of 3.12 eV for the multilayer film deposited with a 30-nm Cu metallic interlayer. Moreover, the optical conductivity increased as the Cu interlayer thickness increased. Transmittance plots with reasonable numbers of interference fringes were employed to calculate the refractive index of the examined multilayers. The results indicated that the values of n gradually increased with increasing the Cu metallic interlayer thickness. The dispersion energy Ed and the single-oscillator energy Eo were determined using a WDD single oscillator model. [ABSTRACT FROM AUTHOR]

The preparation of zirconium hydrogen phosphate, α-Zr(HPO4)2 · H2O (α-ZrP), and its tin dopped derivatives were described. The structural and textural properties of the prepared materials were examined and their effect on catalytic performance in the removal of dyes such as methyl red and methylene blue from the aqueous solutions was revealed. The crystalline zirconium hydrogen phosphate was prepared by the interaction between zirconium tetrachloride and phosphoric acid in the presence of fluoric acid. The α-ZrP samples doped with tin were obtained by the impregnation method. X-ray diffraction, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy and nitrogen adsorption analysis were applied to explore the structural and textural properties of α-ZrP modified by the addition of various amounts of tin. The obtained results indicated a significant effect of the tin amount on these properties. As a result of tin addition, a gradual decrease in the crystallinity of the samples was observed with the appearance of preferred orientation for the [002] planes. These changes coincided with an increase in the surface area and the total pore volume as well as a decrease in pore diameter. Investigation of the photocatalytic activity of the studied materials in the degradation methyl red and methylene blue indicated a significant increase in the degradation extent of the dyes with increasing amount of tin. [ABSTRACT FROM AUTHOR]

Owing to the desired mechanical and biomedical characteristics of TiN-based coatings and the encourage features of pulsed magnetron sputtering, the current study was conducted to deposit Ti-Al-N thin film on AISI 316 using DC pulsed magnetron sputtering. All processing parameters were constant excluding the pulsed magnetron power which was varied from 100 to 175 W. The effect of processing power on the structure, mechanical, electrochemical, and biocompatibility characteristics of Ti-Al-N thin films were inspected. X-ray outlines the formation of (Ti, Al)N solid solution with (111) preferred orientation at high-pulsed magnetron powers. The outcomes of this study demonstrated that the Vickers's microhardness of Ti-Al-N coatings increased with increasing pulsed power to record a value of nearly 810 HV0.015 at 175 W. Moreover, the wear characteristics and the friction coefficient of the coated AISI 316 with Ti-Al-N were ascendant as compared with the uncoated substrate. The wear rate of Ti-Al-N films deposited at pulsed power of 175 W recorded a value of nearly 4.7 × 10−6 mm3/Nm which was very low compared with that of stainless steel substrate (3.2 × 10−4 mm3/Nm). The biological peculiarities of Ti-Al-N films were examined by exploring the proliferation rate of MC3T3-E1 osteoblast cells on the film surface. The results reflected that the proliferation rate of the osteoblast cells were enhanced on Ti-Al-N films deposited at pulsed powers of 150 and 175 W. The biological attitudes were discussed according to the results of surface roughness and surface energy besides the surface chemical compositions. [ABSTRACT FROM AUTHOR]

To optimize the tribo-mechanical performance of thick Ti-Si-CN nanocomposite coatings for a wide range of harsh industrial applications, reactive gases of nitrogen and trimethylsilane were employed with specific flow rates of PEMS process. Plasma-enhanced magnetron sputtering (PEMS) was employed for depositing thick Ti-Si-C-N nanocomposite (22-27 µm) on Ti-6Al-4V substrates at relatively high deposition rate up to 4.5 µm/h. Controlling the nitrogen partial pressure ratio PN2/(PN2 + PTMS) from 0.29 to 0.69 resulted in controlling the chemical and physical properties of the coatings. The XRD results demonstrated that the crystallinity of the nanocomposite structure increased with the increase in nitrogen pressure ratio. The coating hardness, erosion resistance, sliding wear resistance and corrosion resistance were augmented with increasing the nitrogen content in the plasma atmosphere. The results displayed that the sliding wear resistance of Ti-Si-C-N coatings increased by approximately three orders of magnitude comparing with the uncoated Ti-6Al-4V substrate. At low nitrogen content, low coefficient of friction (0.13-0.15) was achieved. Furthermore, the coating prepared at high nitrogen content reflected greater values of ratios H/E* and H3/E*2 that correlated well with the coating erosion resistance. [ABSTRACT FROM AUTHOR]

Purpose: To compare polypropylene mesh positioned onlay supported by omentum and/or peritoneum versus inlay implantation of polypropylene-based composite mesh in patients with complicated wide-defect ventral hernias.Methods: This was a prospective randomized study carried out on 60 patients presenting with complicated large ventral hernia in the period from January 2012 to January 2016 in the department of Gastrointestinal Surgery unit and Surgical Emergency of the Main Alexandria University Hospital, Egypt. Large hernia had an abdominal wall defect that could not be closed. Patients were divided into two groups of 30 patients according to the type of mesh used to deal with the large abdominal wall defect.Results: The study included 38 women (63.3 %) and 22 men (37.7 %); their mean age was 46.5 years (range, 25-70). Complicated incisional hernia was the commonest presentation (56.7 %).The operative and mesh fixation times were longer in the polypropylene group. Seven wound infections and two recurrences were encountered in the propylene group. Mean follow-up was 28.7 months (2-48 months).Conclusions: Composite mesh provided, in one session, satisfactory results in patients with complicated large ventral hernia. The procedure is safe and effective in lowering operative time with a trend of low wound complication and recurrence rates. [ABSTRACT FROM AUTHOR]

The DC-pulsed magnetron sputtering was employed to deposit Ti-Zr-N thin film on AISI 316 substrates. All the plasma parameters were kept to be constant except the plasma-processing power which was varied from 125 to 250 W. The structure, tribological, electrochemical and biocompatibility properties of Ti-Zr-N films have been investigated. X-ray patterns confirmed the formation of solid solution phase of Ti-Zr-N with different orientations. The results depicted that, the microhardness of Ti-Zr-N film increases with increasing the plasma-processing power to reach a maximum value of approximately 1050 HV0.015 at 200 W. Moreover, the tribological properties of AISI 316 coated with Ti-Zr-N were found to be superior compared with the uncoated sample. The wear rate of the coated sample at 225 W has a value of nearly 0.0034 mm/Nm which is very low in comparison with AISI 316 substrate that has a value of 0.137 mm/Nm. The biological properties of the examined samples were evaluated by investigating the proliferation of MC3T3-E1 osteoblast cells on the surface. The proliferation rate of the osteoblast cells was enhanced on Ti-Zr-N films prepared at low plasma power. It has been demonstrated that the surface roughness and surface energy besides the surface chemical compositions affect the tribo-mechanical and biocompatibility features of Ti-Zr-N surfaces. [ABSTRACT FROM AUTHOR]

The studied samples ZnMoO-MoO, have been prepared by immersing an amount of molybdenum oxide in zinc acetate solution according to the appropriate molar ratio x = ZnO/MoO = 0, 0.2, 0.4, 0.6, 0.8 and 1. These samples were then heated at temperature of 500°C for 3 hours. Prepared samples were characterized using different techniques such as: X-ray diffraction, Fourier spectroscopy, Raman spectroscopy, differential thermal analysis and nitrogen adsorption-desorption measurements. The Photocatalytic activity was studied via degradation of methyl red in aqueous solution when subjected to UV radiation. The results of this work revealed some variations, by increasing ZnO quantity, in phase composition and textural characteristics of ZnMoO-MoO samples. It was found that these changes affect the photocatalytic activity by enhancing the degradation rate of Methyl red during the UV irradiation process. [ABSTRACT FROM AUTHOR]

Different samples of NiKMoO have been prepared by mixing appropriate amounts, in solid state, of Ni and KMoO (PDF ICDD 27-416) according to the molar ratio Ni/KMoO = 0, 0.05, 0.1, 0.2, 0.5, and 1. The prepared samples were characterized using X-ray powder diffraction (XRD), Fourier transform infrared (FT-IR), differential thermal analysis (DTA), nitrogen adsorption apparatus, and UV spectrophotometer. XRD results indicate that the phase composition of the Ni/KMoO samples has been significantly changed with the change in molar ratio of Ni/KMoO. The presence of Ni gave rise to the formation of other new phases identified as KMoO (PDF ICDD 37-1467) and α-NiMoO (PDF ICDD 32-692). The results of FT-IR and DTA also allowed us to track the formation of the above-mentioned substances. The nitrogen adsorption-desorption isotherms and the pore size distribution reveal that the texture of the prepared samples has also been affected by the nickel content. The photocatalytic behaviors of pure KMoO and NiKMoO were studied by means of monitoring the ability of these materials to enhance the degradation under UV irradiation of the methyl red in liquid media. It was found that the phase composition is the most influential parameter in the photocatalytic behavior of the studied samples. [ABSTRACT FROM AUTHOR]

The best way to protect yield loss of soybean [ Glycine max (L.) Merr.] due to sudden death syndrome (SDS), caused by Fusarium virguliforme (Aoki, O'Donnel, Homma & Lattanzi), is the development and use of resistant lines. Mapping quantitative trait loci (QTL) linked to SDS help developing resistant soybean germplasm through molecular marker-assisted selection strategy. QTL for SDS presented herein are from a high-density SNP-based genetic linkage map of MD 96-5722 (a.k.a 'Monocacy') by 'Spencer' recombinant inbred line using SoySNP6K Illumina Infinium BeadChip genotyping array. Ninety-four F lines were evaluated for 2 years (2010 and 2011) at two locations (Carbondale and Valmeyer) in southern Illinois, USA to identify QTL controlling SDS resistance using disease index (DX). Composite interval mapping identified 19 SDS controlling QTL which were mapped on 11 separate linkage group (LG) or chromosomes (Chr) out of 20 LG or Chr of soybean genome. Many of these significant QTL identified in one environment/year were confirmed in another year or environment, which suggests a common genetic effects and modes of the pathogen. These new QTL are useful sources for SDS resistance studies in soybean breeding, complementing previously reported loci. [ABSTRACT FROM AUTHOR]

Crystalline titanium phosphate α-Ti(HPO) ⋅ HO (α-TiP) has been prepared by reaction between phosphoric acid solution and titanium chloride in the temperature range 60-80 °C. The solid obtained has been treated, in solid state with different concentrations of either cobalt or nickel. The pure and derivative materials are characterised using X-ray powder diffraction, Fourier transform IR, differential thermal analysis, and nitrogen adsorption. Due to their higher degree of hydration, the cobalt atoms are more sorbed by (α-TiP), where they enter into the cavities (containing the water molecules) between the layers of titanium phosphate. It is found that this process can induce small expanding of the interlayer spacing in the C direction and losing the crystallinity in the other directions. For the nickel, after sorption of more than 20%, an atomic layer may be formed preventing (α-TiP) from accommodating any more nickel ions in its framework, this is displayed by the appearance of diffraction peaks related to unsorbed nickel. The DTA curves indicate that more crystalline α-TiP materials have higher transition temperature. The nitrogen adsorption isotherms give an indication that when the cobalt atoms are sorbed by α-TiP, the latter is transformed from microporous to mesoporous material while it keeps its pore uniformity in the case of nickel. [ABSTRACT FROM AUTHOR]

The reactivity of aluminum molybdate with cobalt was studied. Pure materials have been synthesized by the solid state method using AlO and MoO in proportional quantities. The product then mixed with different quantities of Cobalt in molar ratio (Co/Al(MoO) = 0.1, 0.2,0.3, 0.4, 0.5, 0.6, 0.8 and 1). The pure initial and resultant materials were characterized using powder x-ray diffraction, Fourier transform IR (FTIR), differential thermal analysis (DTA) and nitrogen adsorption. The results suggest that Co, when mixed at fixed temperature with Al(MoO) in the solid state, does not remain inert. This statement is based on the absence of any detectable free cobalt in any sample by the techniques which were employed. Two other phases CoMoO and MoO appear gradually besides the original phase, with increasing the molar ratio. The CoMoO starts to appear overall the used molar ratio range while MoO shows up only for molar ratio higher than 0.6. The appearance of these two phases, detected by x-ray diffraction, has also been confirmed by FTIR and DTA measurements. The reactivity of cobalt towards aluminum molybdate is manifested also by the modification of the adsorption isotherm and pore size distribution where a mesoporosity has been clearly shown for samples containing molar ratio higher than 0.6. [ABSTRACT FROM AUTHOR]

Mesenchymal stem cells (MSC) are a group of clonogenic cells present among the bone marrow stroma and capable of multilineage differentiation into mesoderm-type cells such as osteoblasts, adipocytes and chondrocytes. Due to their ease of isolation and their differentiation potential, MSC are being introduced into clinical medicine in variety of applications and through different ways of administration. Here, we discuss approaches for isolation, characterization and directing differentiation of human mesenchymal stem cells (hMSC). An update of the current clinical use of the cells is also provided.Gene Therapy (2008) 15, 109–116; doi:10.1038/sj.gt.3303067; published online 8 November 2007 [ABSTRACT FROM AUTHOR]

DNA marker maps based on single populations are the basis for gene, loci and genomic analyses. Individual maps can be integrated to produce composite maps with higher marker densities if shared marker orders are consistent. However, estimates of marker order in composite maps must include sets of markers that were not polymorphic in multiple populations. Often some of the pooled markers were not codominant, or were not correctly scored. The soybean composite map was composed of data from five separate populations based on northern US germplasm but does not yet include ‘Essex’ by ‘Forrest’ recombinant inbred line (RIL) population (E × F) or any southern US soybean cultivars. The objectives were, to update the E × F map with codominant markers, to compare marker orders among this map, the Forrest physical map and the composite soybean map and to compare QTL identified by composite interval maps to the earlier interval maps. Two hundred and thirty seven markers were used to construct the core of the E × F map. The majority of marker orders were consistent between the maps. However, 19 putative marker inversions were detected on 12 of 20 linkage groups (LG). Eleven marker distance compressions were also found. The number of inverted markers ranged from 1 to 2 per LG. Thus, marker order inversions may be common in southern compared to northern US germplasm. A total of 61 QTL among 37 measures of six traits were detected by composite interval maps, interval maps and single point analysis. Seventeen of the QTL found in composite intervals had previously been detected among the 29 QTL found in simple interval maps. The genomic locations of the known QTL were more closely delimited. A genome sequencing project to compare Southern and Northern US soybean cultivars would catalog and delimit inverted regions and the associated QTL. Gene introgression in cultivar development programs would be accelerated. [ABSTRACT FROM AUTHOR]

This study focuses on the phase transformation induced during mixing fixed quantities of MoO3 and Al2O3 or aluminum powder (2, 3, 4, 5, 10, 20, 40, 50%). Different solid solutions were identified by x-ray powder diffraction, FTIR, and DTA. In the Al2O3 concentration range 2–20%, the only phase present besides MoO3 is Al2(MoO4)3. The concentration of this latter phase increases with increasing Al2O3 concentration, while the concentration of MoO3 decreases at the same time. For high concentrations of Al2O3 (more than 20%), MoO3 disappears completely, and Al2(MoO4)3 becomes the dominant phase. When MoO3 is mixed with various concentrations of aluminum powder, three kinds of samples were obtained. For aluminum concentration less than 4%, no other phase than MoO3 is present. For the concentration of aluminum in the range 4–20%, a new phase of Al2(MoO4)3 is observed. This phase increases while MoO3 decreases with increasing aluminum loading. At high concentrations of aluminum (more than 20%), the MoO3 disappears completely, and a new phase M0.975Al0.025O2 is present besides the Al2(MoO4)3 already formed. [ABSTRACT FROM AUTHOR]

Age-related decreased osteoblast function is a well-known but poorly understood phenomenon. Previous studies that examined the effects of donor age on osteoblast functions employed in vitro assays that may not reflect the true osteoblast capacity for bone formation. Thus, we have developed an in vivo assay for quantifying the bone forming capacity (BFC) and we compared the BFC of osteoblastic cells obtained from young and old donors. Osteoblasts were obtained from human bone marrow stromal cell cultures and implanted subcutaneously in immuno-deficient mice (NOD/LtSz-Prkdcscid). After 8 weeks, the implants were removed and embedded un-decalcified in methyl methacrylate (MMA). Sections were stained histochemically with Goldner's Trichrome stain and immuno-histochemically using human-specific antibodies against known osteogenic markers. Implanted human marrow stromal cells (hMSC) were able to form bone in vivo. The donor origin of bone was verified using several human-specific antibodies. Dose–response experiments demonstrated that 5 × 105 hMSC per implant gave the maximal bone formation after 8 weeks. No difference in BFC was observed between cells obtained from young (24–30 years old; mean age 27 ± 2 years, n = 5) and old (71–81 years old; mean age 75 ± 4 years, n = 5) donors. Our study demonstrates that the capacity of hMSC to form bone in vivo is maintained with age and suggests that the observed senescence-associated decrease in bone formation is due to a defect in the bone microenvironment, the nature of which remains to be determined. [ABSTRACT FROM AUTHOR]

The presence of non-hematopoietic stem cells in the human umbilical cord blood (hUCB) is debated. In this study, we report the isolation of a population of fibroblast-like cells with osteogenic and adipogenic potential that resembles the stromal stem cells found in the bone marrow. Low-density mononuclear cells isolated from hUCB formed few adherent colonies with fibroblast-like morphology after a few days in culture. At confluence, the polyclonal cell populations were characterized. Using FACS analysis and immunocytochemistry, the cells were found to express HLA-ABC, CD9, vimentin, the b subunit of prolyl-4-hydroxylase, integrins a1(CD49a), integrin a3 (CD49c), integrin a5(CD49e), and cytokeratin 18. Furthermore, the cells expressed constitutively transcripts of osteoblast-specific markers: Cbfa1/Runx2, alkaline phosphatase (AP), and collagen type I, and formed a mineralized matrix in vitro visualized by Alizarin red staining. In the presence of normal horse serum and dexamethasone (10?7 M), the cells formed foci of adipocytes. When the cells were implanted mixed with hydroxyapatite/tricalcium phosphate powder in the subcutis of immunocompromised mice for 8 weeks, they formed osteogenic tissue and a myelosupportive microenvironment that enclosed hematopoietic cells and adipocytes. Our results demonstrate the presence of circulating stem cells with osteogenic and adipogenic differentiation potential in hUCB and may encourage the use of hUCB as a potential source for stem cells to be utilized in cell therapy protocols for various diseases. [ABSTRACT FROM AUTHOR]

Cavernous angiomas are mostly small intracranial vascular lesions which can be intraoperatively localized by sonography or stereotactic methods. This paper compares the results of cavernous angioma surgery localized by frame-based vs frameless techniques. Thirty-nine patients with cortical or subcortical lobar cavernoma were operated on by a microsurgical trans-sulcal approach. The localization of the lesion was performed in 19 (49%) patients by frame-based technique and in 20 (51%) patients by frameless navigation. In 22 (56%) of the patients, the cavernomas were located in an eloquent cortical area. Ten of 22 of these lesions were localized by frame-based stereotaxy and 12/22 by frameless navigation. The patients demonstrated the following preoperative symptoms: seizures 20 (51%), hemorrhage 18 (46%), focal neurologic deficit 11 (28%), and headache three (7%), and three (7%) were asymptomatic. Thirteen of 19 patients localized with frame-based stereotaxy were postoperatively asymptomatic or their preoperative neurological symptoms improved. Four of 19 had a transitory neurologic deficit and 2/19 a permanent worsening. Seventeen of 20 patients localized by frameless navigation were asymptomatic or neurologically improved. Three out of 20 suffered from a transient neurologic deficit. Regarding the seizures, 14 (70%) patients were postoperatively free of seizures, three (15%) were improved, and three (15%) were unchanged. The frameless navigation was superior regarding the flexibility for approaches along the skull base and midline, and the frame-based method was superior regarding the accuracy for very small lesions (less than 7 mm). In other cases, both methods were equal. Frame-based and frameless stereotactic methods are useful in the localization of small cavernous angiomas. They make it possible to remove cavernous angiomas in eloquent cortical regions with low risk of a permanent neurologic deficit. [ABSTRACT FROM AUTHOR]

Osteoblasts and adipocytes share a common precursor cell in the bone marrow stroma, termed marrow stromal cell (MSC). As the volume of bone adipose tissue increases in vivo with age, we hypothesized that decreased bone formation observed during aging and in patients with osteoporosis (OP) is the result of enhanced adipogenesis and decreased osteoblastogenesis from the MSCs. Thus, cultures of MSCs were established from young donors (age 18–42, n = 34), elderly healthy donors (age 66–78, n = 20), and patients with OP (age 58–76, n = 15). Cells were cultured for 2 weeks in an adipogenic medium (containing 15% horse serum and 100 nM dexamethasone), osteogenic medium (containing 10% fetal calf serum [FCS] and 10 nM calcitriol), or control medium (10% FCS). The MSCs were identified by their abilities to form colonies. Total number of colonies, osteoblastic colonies stained positive for alkaline phosphatase (AP+), and adipocytic colonies containing adipocytes (Ad+) were quantitated. In addition, steady state mRNA levels of gene markers of adipocytic and osteoblastic phenotypes were determined using reverse-transcriptase polymerase chain reaction (RT-PCR). The adipogenic and osteogenic media induced cell differentiation and the expression of adipocytic and osteoblastic lineage-specific markers, respectively. We found no age-related changes in the osteoblastic or adipocytic colony formation or the steady state levels of mRNA of the adipogenic or osteogenic gene markers. Cells obtained from patients with OP showed a pattern of differentiation similar to those of age-matched controls. In conclusion, MSCs maintain their differentiation potential during aging and in patients with OP. Other mechanisms responsible for age-related decrease in bone formation need to be determined. [ABSTRACT FROM AUTHOR]

Aging of the human skeleton is characterized by decreased bone formation and bone mass and these changes are more pronounced in patients with osteoporosis. As osteoblasts and adipocytes share a common precursor cell in the bone marrow, we hypothesized that decreased bone formation observed during aging and in patients with osteoporosis is the result of enhanced adipognesis versus osteoblastogenesis from precursor cells in the bone marrow. Thus, we examined iliac crest bone biopsies obtained from 53 healthy normal individuals (age 30–100) and 26 patients with osteoporosis (age 52–92). Adipose tissue volume fraction (AV), hematopoietic tissue volume fraction (HV) and trabecular bone volume fraction (BV) were quantitated as a percentage of total tissue volume fraction (TV) (calculated as BV + AV + HV) using the point-counting method. We found an age-related increase in AV/TV (r = 0.53, p < 0.001, n = 53) and an age-related decline in BV/TV (r = -0.46, p < 0.001, n = 53) as well as in the HV/TV (r = -0.318, p < 0.05, n = 53). There was an age-related inverse correlation between BV/TV and AV/TV (r = -0.58, p < 0.001). No significant correlation between the AV/TV and the body mass index (r = 0.06, n.s., n = 52) was detectable. Compared with age-matched controls, patients with osteoporosis exhibited an increased AV/TV (P < 0.05) and decreased BV/TV (P < 0.05) but no statistically significant difference in HV/TV. Our data support the hypothesis that with aging and in osteoporosis an enhanced adipogenesis is observed in the bone marrow and that these changes are inversely correlated to decreased trabecular bone volume. The cellular and molecular mechanisms mediating these changes remain to be determined. [ABSTRACT FROM AUTHOR]

Aging is associated with decreased trabecular bone mass and increased adipocyte formation in bone marrow. As osteoblasts and adipocytes share common precursor cells present in the bone marrow stroma, it has been proposed that an inverse relationship exists between adipocyte and osteoblast differentiation. In order to test this hypothesis, we studied mice treated with troglitazone (n = 9) given as a 0.2% of food admixture (2.0 g troglitazone per kg food) for 10 months and control mice (n = 9). Troglitazone is a potent stimulator of adipogenesis acting at the nuclear receptor: peroxisome proliferator activated receptor-gamma (PPARg). Histomorphometric analysis of proximal tibia was performed in order to quantitate the amount of trabecular bone volume per total volume(BV/TV %), adipose tissue volume per total volume (AV/TV %), and hematopoietic marrow volume per total volume (HV/TV %) using the point-counting technique. Bone size did not differ between the two groups. In troglitazone-treated mice, AV/TV was significantly higher than in control mice (4.7 ± 2.1% vs. 0.2 ± 0.3%, respectively, mean ± SD, P < 0.001). BV/TV was similar in the two groups (16.9 ± 5.6% for troglitazone-treated group vs. 14.9 ± 4.7% for control group) as well as ash weight of the vertebrae. HV/TV was reduced in troglitazone-treated mice compared with control mice (78.4 ± 6.8% vs. 84.9 ± 4.7%, respectively, P < 0.05) and the presence of vascular sinusoids was reduced (7.3 ± 1.7% vs. 16.1 ± 5.6%, respectively, P < 0.05). Our data demonstrate that adipogenesis and osteogenesis can be regulated independently. Troglitazone-induced adipogenesis in the bone marrow may be caused by changes in the bone marrow vascularity. [ABSTRACT FROM AUTHOR]

Immunohistochemical staining techniques used on an 11-week-old fetus showed that fetal antigen 2 (FA2) was present intracellularly in endochondral and perichondral osteoblasts, and the immunoreaction was extended into the adjacent bone matrix. Osteoclasts and chondroblasts were found to be FA2 negative. A granular perinuclear intracytoplasmic FA2 immunoreaction was found in cultured osteoblasts and osteogenic osteosarcoma cells, and immunoelectron-microscopical examination revealed a granular immunoreaction product in the rough endoplasmic reticulum. These findings indicate that FA2 is synthesized by osteoblasts and osteogenic osteosarcoma cells. A reaction of immunological identity was found between FA2 purified from second trimester amniotic fluid and serum-free supernatants of cultured osteogenic osteosarcoma cells. This shows that an antigen recognized by the anti FA2 antibody is secreted by these malignant cells. Thus, FA2 may represent a marker for altered bone metabolism, and have a potential in the classification of osteogenic osteosarcoma/ chondrosarcoma. [ABSTRACT FROM AUTHOR]

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The thermal and dielectric spectroscopy of a thiosemicarbazide Schiff base and its nickel and palladium complexes were studied. The Perkin Elmer TGA7 thermal analysis technique was applied to study the effect of the heating rate on the TG curve. A Hioki 3520 RLC tester was used to measure the dielectric spectroscopy in the frequency range 10-10 Hz. The activation energies of the ligand and its complexes were determined, and the d.c. and a.c. conductivities were estimated for the ligand and its Ni(II) complex. The results showed that the Ni(II) complex was present in a dimeric form, while the Pd(II) complex was present in a monomeric form. The insertion of a nickel atom increases the d.c. conductivity. The mechanism of conduction is discussed. [ABSTRACT FROM AUTHOR]

The proliferative capacity and cellular and biochemical characteristics of human trabecular bone osteoblasts were analysed throughout their replicative lifespan in vitro. Like several other cell types, human osteoblasts demonstrated a typical Hayflick phenomenon of cellular aging comprising a period of rapid proliferation until cumulative population doubling level (CPDL) 22 to 24, followed by a phase of slow growth and the final cessation of cell division at CPDL 32 to 34. Comparing young cells (less than 20% lifespan completed) and old cells (more than 90% lifespan completed) revealed a progressive increase in population doubling (PD) time, a decrease in attachment frequency, a decrease in the number of S-phase positive cells, a decrease in the rates of DNA, RNA and protein synthesis, an increase in the protein content per cell and an increased proportion of senescence-specific β-galactosidase positive cells. While osteoblastic production of collagen type I decreased progressively during aging, alkaline phosphatase activity dropped rapidly after the first few passages and then remained constant during the rest of the proliferative lifespan. Significant morphological changes from thin and spindle-shaped early passage young cells to large, flattened and irregularly shaped late passage old cells full of intracellular debris were observed. In comparison, osteoblasts established from an osteoporotic bone sample showed a maximum CPDL of less than 5, had a longer PD time and exhibited abnormal senescent morphology. Thus, we have demonstrated for the first time that human osteoblasts, like several other diploid cell types, have a limited proliferative capacity in vitro and undergo aging and senescence as measured by various cellular and biochemical markers. In addition, preliminary studies show that cells from osteoporotic bone have a severely reduced proliferative capacity. This model of bone cell aging facilitates study of the molecular mechanisms of osteoblast senescence as well as factors related to osteoblast dysfunction in patients with osteoporosis. [ABSTRACT FROM AUTHOR]

The direct-current resistivity, β, and Hall coefficient, R , of lightly doped n-type InP samples were measured at temperatures ( T) down to 12K and magnetic fields up to 4.8 kG. A sharp exponential increase in β, as T was decreased, was observed for temperatures below 80 K. The Hall coefficient showed a similar trend, i.e. R increased sharply as T was reduced below 80 K. This is attributed to the freeze-out of conduction electrons onto their donor sites. The donor activation energy, E , calculated from the temperature dependence of the resistivity, was less than the theoretical prediction. An enhanced dielectric constant would be a possible candidate for such behaviour. The initial decrease in β (as T is reduced) recorded in the higher-temperature region is due to impurity scattering probably combined with lattice scattering. [ABSTRACT FROM AUTHOR]

Stripping uranium from Dehpa/kerosene solvent is a crucial step in the recovery of uranium. Stripping was studied using different stripping media mainly ammonium carbonate, phosphoric acid, sulfuric acid, hydrochloric acid and nitric acid. Stripping was measured at different operating conditions such as aqueous concentrations, temperatures, and Dehpa/kerosene concentrations. The results obtained showed that stripping by acid media increases with the acid concentration and follows the order: HF>H3PO4>H2SO4>HCl>HNO3. To achieve higher stripping by phosphoric acid it was found necessary to increase the temperature to 50°C, the acid concentration to 5 mol/l and to reduce the uranium to U4+. Stripping by basic media was found to increase with increasing concentration of the stripping media and to follow the order: Na2CO3>(NH4)2CO3>NH4HCO3. Stripping by ammonium carbonate was found to increase with temperature and carbonate concentration. The stripping was optimized at 0.5 mol/l carbonate concentration and at a temperature of 50°C. Stripping was decreased by increasing concentration of Dehpa in kerosene and was depressed more by adding the synergant Topo to the Dehpa solvent especially at 1/4 mol/mol ratio. [ABSTRACT FROM AUTHOR]

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Insulin-like growth factors (IGF)-I and IGF-II are produced by osteoblasts and are important paracrine/autocrine regulators of osteoblast proliferation and differentiation. Estrogen has been reported to increase gene expression of IGF-I in rodent osteoblasts. However, because species differences have been demonstrated in expression of various aspects of the IGF system in bone cells, it is not known whether this action also occurs in human osteoblasts. Thus, we assessed the effects of estrogen treatment on IGF-I and IGF-II gene expression in vitro in a recently developed human fetal osteoblast cell line that has high levels of estrogen receptors. As assessed by a quantitative reverse transcriptase-polymerase chain reaction method, treatment of hFOB/ER9 cells with 17β-estradiol (E2) increased steady state levels of IGF-I mRNA in a time- and dose- dependent fashion with a maximal increase of 319% ± 33% ( P < 0.01) of control occurring after treatment with 10−7 M E2 for 48 hours. In contrast, E2 did not alter steady state levels of IGF-II mRNA. The pure (type 2) antiestrogens ICI 182,780 (10−7 M) and ICI 164,384 (10−6 M) blocked the E2- induced increase in IGF-I mRNA levels. Interestingly, 4-hydroxytamoxifen (10−7 M), a documented pure antiestrogen in reproductive tissues, also increased IGF-I mRNA to levels similar to those observed in E2-treated cells. Since E2 was shown to mediate its effects on some target genes through a cAMP-dependent pathway, we studied the interaction between E2 and agents that are known to increase intracellular cAMP. Forskolin (10−8 M) and dibutyryl cAMP (10−3 M) increased IGF-I mRNA levels sixfold, and cotreatment with E2 did not affect these changes, consistent with a possible mediation of the estrogen effect on IGF-I gene expression by cAMP. We conclude that in human osteoblastic cells, the IGF-I gene is a target for estrogen action, suggesting that IGF-I may mediate part of the effects of estrogen in human bone. [ABSTRACT FROM AUTHOR]

Decreased osteoblastic activity seems to play an important role in the pathogenesis of postmenopausal osteoporosis. The aim of the present study was to examine the direct effects of human growth hormone (GH) on proliferation and differentiation of osteoblastic cells obtained from patients with postmenopausal osteoporosis and age-matched normals and to compare the cellular responses induced by GH between the two groups. Osteoblast cultures (human marrow stromal osteoblast-like cells) were established from bone marrow aspirates obtained from 9 osteoporotic patients and 12 age-matched normals. Effects on cell proliferation and cell differentiation markers [alkaline phosphatase (AP)], procollagen type I propeptide (PICP), and osteocalcin] were assessed. GH stimulated 3H-thymidine incorporation into DNA in cell cultures of osteoporotic patients to a maximum of 158 +/- 14% of no-treatment controls (n = 9, P < 0.001) and to 203 +/- 52% (n = 9, P < 0.001) in normals. GH increased cell number as measured by methylene blue (MB) assay in cells of osteoporotic patients to 138 +/- 10% (P < 0.05, n = 7) and in normals to 138 +/- 12 (P < 0.05, n = 7). GH alone reduced cellular AP production: 61 +/- 3.8% (P < 0.05, n = 7) versus 65 +/- 16% (P < 0.05, n = 7) and cellular PICP production: 79 +/- 6% (P < 0.05, n = 7) versus 69 +/- 16% (n.s., n = 7), in cell cultures of osteoporotics and normals, respectively.(ABSTRACT TRUNCATED AT 250 WORDS) [ABSTRACT FROM AUTHOR]

In this study we investigated the direct, short-term effects of human growth hormone (hGH) on the biology of normal adult human osteoblast-like (hOB) cells cultured from trabecular bone explants. In Subconfluent cultures, hGH stimulated hOB proliferation in a dose-dependent fashion (P < 0.001, n = 15) with half-maximal effects at a concentration of 10 ng/ml. These mitogenic effects were detectable within 24 hours as shown by bromodeoxyuridine labeling. In confluent cultures containing mainly quiescent cells, hGH increased levels of alkaline phosphatase (P < 0.05, n = 10) and to a lesser degree levels of procollagen type I carboxyterminal propeptide (PICP) (P = 0.07, n = 9). Effects on osteocalcin (bone GLa protein, BGP) levels were highly variable among different cell strains and only 7 of 10 cell strains showed a stimulatory response (P = 0.16). We also studied the effects of hGH on osteoblastic production of insulin-like growth factor I (IGF-I) and IGF-II as well as the production of GH-dependent, insulin-like growth factor binding protein 3 (IGFBP-3). Under basal conditions, human osteoblasts produced IGF-II and IGFBP-3 in the conditioned medium. When stimulated with hGH, minor insignificant increase in both IGF-II and IGFBP-3 (125% and 126% of control, respectively) were detectable. No IGF-I was detectable in the conditioned medium under basal conditions or after stimulation with hGH. In conclusion, the results obtained in this study suggest that GH exerts direct anabolic effects on human osteoblasts. [ABSTRACT FROM AUTHOR]

We examined the role of sleep, growth hormone (GH), and parathyroid hormone [PTH(1-84)] as regulators of the diurnal rhythm of the osteoblastic bone marker, serum osteocalcin (OC). Nine normal subjects were followed with hourly blood sampling during one 24-hour period with norsleep deprivation. We found that the rhythm in serum OC did not exhibit significant changes ( P>0.50). Serum OC (mean±SE) was 30.9±2.5 μg/liter during sleep (2330-0730 hours) versus 29.9±4.9 μg/liter during sleep deprivation (not significantly different). The serum GH rhythm was significantly different on the two occasions ( P<0.01). A maximum GH peak (mean±SE) of 10.3±2.4 μg/liter occurred at 0136 hours±6 minutes during sleep compared with a maximal peak of 7.6±1.2 μg/liter ( P<0.01) at 0245 hours ±20 minutes ( P<0.01) during sleep deprivation. During sleep (2330-0730 hours), mean serum GH was 3.61±0.60 μg/liter compared with 2.39±0.40 μg/liter during sleep deprivation ( P<0.005). Small insignificant changes occurred in serum PTH(1-84) and serum ionized calcium during the two occasions. We conclude that sleep and GH are not acute controlling factors of the diurnal rhythm in serum OC and the role of serum PTH(1-84) remains unsettled. [ABSTRACT FROM AUTHOR]

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The effects of γ-irradiation on the optical properties of polyoxymethylene (POM) compacts are studied at room temperature. A UV-visible spectrometer is used to study the optical absorbency in the wavelength range 200–1100 nm. The optical energy of both direct and indirect transitions as well as the energy band tail ΔE is determined as a function of γ exposure dose. The results obtained showed that the POM compacts became brittle as the γ-radiation dose reaches 5 Mrad. In the meanwhile, the wavelength of the optical band tail λg increases to a maximum at 2 Mrad and the energy band tail ΔE reaches 5 eV at the same dose. Both direct and indirect energies of transition decrease with the irradiation dose. The results can be explained on the basis of γ-irradiation-induced changes due to cross-linking in the POM. [ABSTRACT FROM AUTHOR]