Search

Mg-2·2Nd- xSr-0·3Zr alloys (wt-%, x = 0, 0·4, 0·7 and 2·0) were prepared by gravity casting to study the effects of Sr addition on the microstructure and corrosion resistance of Mg-Nd-Zr alloys in simulated body fluid (SBF). Phases were identified by X-ray diffraction, and microstructure was observed with optical microscopy and scanning electron microscopy. Corrosion resistance of the alloys was determined by evaluating mass loss and hydrogen evolution during immersion in SBF. Mg17Sr2 phase was formed, and the grain size decreased with additional Sr addition. For the grain refinement and more continuous second phase, which could improve the corrosion resistance, the alloy with 0·7 wt-%Sr showed the slowest corrosion rate, whereas the alloy with 2·0 wt-% showed the fastest corrosion rate due to the increased volume fraction of Mg17Sr2, which led to severe local microgalvanic corrosion. [ABSTRACT FROM AUTHOR]

TiO2 nanomaterials have many promising applications in environmental and energy areas due to their advantages of physical and chemical stability, high activity, non-toxicity and low price. In the present paper, the hierarchical TiO2 nanomaterials with thickness >10 μm were synthesised using Ti-Cu amorphous alloy as the starting material. The field emission scanning electron microscopy, X-ray diffraction and transmission electron microscopy were used to characterise the morphology and structure of the TiO2 nanomaterials. The hierarchical TiO2 nanomaterials exhibited high specific areas of >100 m2 g−1. The phase composition of TiO2 was controlled by adjusting the concentration of SO42− in the immersing solution. The influence mechanism of SO42− on phase composition of TiO2 nanomaterials was discussed. The mixed phase of anatase and rutile had higher photocatalytic efficiency than single phase in degradation of rhodamine B under visible light. The hierarchical TiO2 nanomaterials had potential applications in photocatalyst and solar cell. [ABSTRACT FROM AUTHOR]

Magnesium hydrate is the absorbent in magnesia scrubbing wet flue gas desulfurization. Its dissolution rate has a great impact on the performance of SO2removal. Further, magnesia is the heat decomposition product of magnesite. The effect of magnesite heat decomposition temperature on the dissolution rate of magnesium hydrate is investigated in this study. As can be seen from the experimental results, magnesium hydrate dissolution rate increased with increasing heat decomposition temperature up to 700°C and then decreased with the increase of heat decomposition temperature. This is caused by the change of magnesite heat decomposition mechanism at a different heat decomposition temperature. [ABSTRACT FROM PUBLISHER]

We have deduced a theoretical relation between the pulsation and orbital-periods of pulsating stars in close binaries based on their Roche lobe filling. It appears to be of a simple linear form, with the slope as a function of the pulsation constant, the mass ratio, and the filling factor for an individual system. Testing the data of 69 known eclipsing binaries containing δ-Sct-type components yields an empirical slope of 0.020 ± 0.006 for the Ppul-Porb relation. We have further derived the upper limit of the Ppul/Porb ratio for the δ-Sct stars in eclipsing binaries with a value of 0.09 ± 0.02. This value could serve as a criterion to distinguish whether or not a pulsator in an eclipsing binary pulsates in the p-mode. Applying the deduced Ppul-Porb relation, we have computed the dominant pulsation constants for 37 δ-Sct stars in eclipsing systems with definite photometric solutions. These ranged between 0.008 and 0.033 days with a mean value of about 0.014 days, indicating that δ-Sct stars in eclipsing binaries mostly pulsate in the fourth or fifth overtones. [ABSTRACT FROM AUTHOR]

Polyoxypropylene diamine has been used as shale hydration inhibitor in drilling fluid and exhibited outstanding performance. The authors describe the inhibition characteristics of KCl and polyoxypropylene diamine and provided a comparative assessment. Through bentonite inhibition test, bulk hardness test, hot-rolling dispersion test, slake durability test, fluid loss test, linear swelling test and X-ray diffraction test, the inhibitive properties of potassium chloride, and polyoxypropylene diamine were evaluated. The results indicate that polyoxypropylene diamine is superior to potassium chloride in shale stabilization, which can effectively suppress the hydration and swelling of clay and play an important role in permanent stabilization with a relatively low concentration. Moreover, the mechanisms of the two inhibitors are briefly analyzed. [ABSTRACT FROM PUBLISHER]

Biodegradable magnesium alloy with proper yield strength, high ultimate strength and elongation is a potential candidate for cardiovascular stent. Nevertheless, magnesium alloy with high ultimate tensile strength always exhibits high yield strength, which is not suitable for the plastic deformation of cardiovascular stent during implantation. Solution treatment was conducted on the as extruded Mg-2·7Nd-0·2Zn-0·4Zr alloy in order to reduce the high yield ratio, and the biocorrosion behaviour of the alloy was also evaluated in artificial plasma. The results show that the grains of the alloy grow, and the second phase reduces with increasing solution treatment temperature. The yield strength decreases gradually, and the ultimate tensile strength still keeps a high level due to the remarkable workhardening. The yield ratio of the alloy reduces from 92 to 57%. The corrosion resistance of the alloy after solution treatment is improved slightly when the temperature is <475°C. [ABSTRACT FROM AUTHOR]

Magnetic micro/nanostructures with controlled morphology have drawn intensive attention due to their interesting physicochemical properties and potential applications in micro/nanodevices. In this study, one-dimensional nanochains with an average diameter of about 140 nm were prepared by a magnetic-field-assisted chemical reduction of with hydrazine hydrate free of any template or surfactant. It was found that the morphology and the size of the chains could be adjusted by changing the complexant used in the synthesis. The usage of surfactant in the synthesis would retard the firm connection of nanoparticles and thus resulted in the formation of nanochains consisting of loosely aggregated nanoparticles. The magnetic measurement at room temperature indicated that the coercivity of the sample reached 133.2 Oe, which was much higher than that of bulk metal. Ni nanochains were prepared by reduction of Ni2+ with N2H4 in the presence of an external magnetic field, which exhibit improved coercivity. [ABSTRACT FROM AUTHOR]

In this paper, a new smoothness indicator is proposed to improve the finite-difference lattice Boltzmann method (FDLBM). The necessary and sufficient conditions for convergence are derived. A detailed analysis reveals that the convergence order is higher than that of the previous finite-difference scheme. The coupled double distribution function (DDF) model is used to describe discontinuity flows and verify the improvement. Numerical simulations of compressible flows with shock wave show that the improved finite-difference lattice Boltzmann scheme is accurate and has less dissipation. The numerical results are found to be in good agreement with the analytical results and better than those of the previous scheme. [ABSTRACT FROM AUTHOR]

Progressive symmetrical erythrokeratodermia (PSEK) is a rare inherited cornification disorder characterized by symmetrical erythematous hyperkeratotic plaques. The genetic basis for PSEK is not clear. PSEK shares many clinical features with erythrokeratodermia variabilis (EKV), which is associated with mutations in genes coding for gap junction beta ( GJB) 3 and 4. A mutation in the loricrin gene ( LOR) was found in patients with PSEK, who were members of a family with Vohwinkel syndrome. It would therefore be of interest to determine if PSEK is also caused by mutations in these genes. To examine the mutation status of GJB3, GJB4 and LOR in patients with PSEK and in control subjects. Genomic DNA samples from 25 patients with PSEK and 56 healthy controls were examined by sequencing analysis of the coding sequences of GJB3, GJB4 and LOR. There were no mutations found in any of these three genes. PSEK is a disorder distinct from EKV, and the true pathogenesis of PSEK remains unknown. [ABSTRACT FROM AUTHOR]

Disseminated superficial porokeratosis (DSP) is an autosomal dominant epidermal keratinization disorder. The genetic basis for DSP has not been clearly elucidated. We previously mapped the locus for DSP to a large region (5.7 Mb) at 18p11.3 in a four-generation Chinese family with DSP, but no gene responsible for porokeratosis has been identified to date. To narrow the critical region for DSP, thereby facilitating the identification of this disease gene and possibly leading to an understanding of the pathogenesis of porokeratosis, genotyping was performed on the same Chinese family with DSP using nine heterozygous single-nucleotide polymorphism markers at 18p11.3. We found the locus of DSP to be located within a 2.7 Mb region between markers rs58085394 and rs238533. Our study provides a map location for isolation of a gene causing DSP. [ABSTRACT FROM AUTHOR]

CeO2 triangular microplates were obtained via thermal treatment of triangular precursor, which were synthesised through a convenient precipitation route using Ce(NO3)3·6H2O as the cerium source and NH4NO3 as the mineralising agent. The field emission scanning electron microscopy (FESEM) images show the obtained uniform trigon-like particles with edge lengths ranging from 2 to 5 um. The optical absorption spectrum indicates that the CeO2 trigons have a direct band gap of 3.65 eV. The electrochemical characteristics of the trigon-like CeO2 structures were studied by investigation of cyclic voltammetry (CV). It was found that the CeO2 trigons can greatly improve the electron transfer ability. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented regarding the study on the risk of skin disease epidermolytic hyperkeratosis following the mutation of keratin 10 gene.

In order to better understand the failure behaviour of brittle or quasi-brittle materials, we developed a numerical model to analyse the creation of a main macro-crack from a large number of micro-cracks. The boundary element method is used to simulate numerically the formation of a main macro-crack by the growth and the coalescence of the micro-cracks. Different two-dimensional panels in PMMA with initial micro-cracks are studied. The macroscopic responses of the panels are observed by simulating the damage process induced by the growth of micro-cracks. The ultimate tensile stress of the material can be then determined. The material toughness heterogeneity is taken into account in the developed model. The toughness heterogeneity is considered as existence of different energy barriers for the growth of micro-cracks. The influences of different parameters such as the level of local stress concentration, the density and the initial length of micro-cracks and the toughness heterogeneity on the failure behaviour of the materials are also studied. The numerical results show that the present model is realistic and efficient. It can be used to describe brittle or quasi-brittle material failure due to the creation of a main macro-crack from micro-cracks. [ABSTRACT FROM AUTHOR]

This study examines the PNA associated atmospheric diabatic heating by linearly isolating the influence of ENSO. The analysis is based on the NCEP–NCAR and ERA-40 reanalyses and a 1,000-year-long integration of the CCCma coupled climate model. Both the vertically integrated and three-dimensional diabatic heating are examined. The Rossby wave sources in association with the PNA are also diagnosed. The PNA-related heating is confined outside the tropics and is dominated by anomalies in the eastern Pacific, with a north–south dipole structure in mid-latitudes and the northern subtropics. The heating anomalies change sign with height in mid-latitudes but have the same sign throughout the troposphere in the northern subtropics. Relatively weak heating anomalies also appear in mid-latitudes, downstream of the heating dipole over North America and the western North Atlantic. The heating anomalies are largely supported by the advections related to the mean state throughout the troposphere, and partially damped by the advections related to the eddy effect, particularly at the upper troposphere over the North Pacific. Broadly similar patterns are seen from the NCEP–NCAR and ERA-40 reanalyses. Yet anomalous heating centers are generally located at relatively lower troposphere for the ERA-40 with respect to the NCEP–NCAR. The tropical heating anomalies are rather weak, remarkably different from those related to ENSO variability. In addition, the Rossby wave source collocates with the atmospheric diabatic forcing in the mid-high latitudes over the PNA sector, and shows no forcing source in the tropics. The results demonstrate possible forcing in the mid-high latitudes, regardless of tropical heating for the PNA teleconnection. The modeled heating and wave forcing anomalies in association with the modeled PNA compare reasonably well with the reanalysis-based estimates, increasing confidence in the observational results. The analysis provides further evidence of the independence of the PNA on ENSO from the diabatic heating point of view. [ABSTRACT FROM AUTHOR]

Objective. Keratitis–ichthyosis–deafness syndrome (KID) is a rare congenital disorder. Mutations in the GJB2 gene have recently been identified as the causative mutations of KID. Aim. To define the GJB2 mutation in a Chinese patient with KID and brain malformation. Methods. Genomic DNA was extracted from peripheral blood and used to amplify the GJB2 gene. Direct sequencing and endonuclease digestion were used for mutation analysis. Results. We identified a heterozygous missense mutation (D50N) in the GJB2 gene in this patient. Conclusions. These results indicate that KID syndrome in this patient was caused by a dominant mutation of GJB2. [ABSTRACT FROM AUTHOR]

Cd(OH)2 nanobelts have been synthesized in high yield by a convenient polyol method for the first time. XRD, XPS, FESEM, and TEM were used to characterize the product, which revealed that the product consisted of belt-like crystals about 40 nm in thickness and length up to several hundreds of micrometers. Studies found that the viscosity of the solvent has important influence on the morphology of the final products. The optical absorption spectrum indicates that the Cd(OH)2 nanobelts have a direct band gap of 4.45 eV. [ABSTRACT FROM AUTHOR]

The feasibility of joining MoSi2 to 316L stainless steel was investigated using the spark plasma sintering technique with nine graded materials. It was demonstrated that dense uniformed joints can be achieved with such graded interlayers because the coefficient of thermal expansion of each interlayer closely matched over a wide temperature range. Furthermore, such a compatibility between the graded interlayers prevented MoSi2 with low toughness from the occurrence of microcracks resulted from the residual stresses formed during cooling of the joint. In addition, it was found that the nine layer joint with a thickness of 1·0 mm for each layer exhibited the minimum residual stress when the compositional exponent is 0·8. [ABSTRACT FROM AUTHOR]

Composites of Sn-Pd particles and multi-walled carbon nanotubes (MWNTs), and of Ni-Co particles and MWNTs were investigated by transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The Sn-Pd particle composites were prepared by impregnation deposition, and the Ni-Co particle composites were prepared by electroless deposition on MWNTs synthesized by a chemical vapor deposition method using thermal catalytic decomposition of hydrocarbon. The morphologies and the microstructure of the deposited particles were investigated upon annealing the composites with and without hydrogen. Both the crystalline particle structure and the particle morphology are observed to be different for the samples annealed with and without hydrogen. [ABSTRACT FROM AUTHOR]

Background. Angiogenesis is the major and key factor for growth and invasion of tumours, including malignant melanoma (MM), but the factors that contribute to tumour angiogenesis are still unclear. Objective. To study expression of endothelial nitric oxide synthase (eNOS) and vascular endothelial growth factor (VEGF) in human MM and their relation to angiogenesis. To investigate the correlation between eNOS and VEGF and the role of nitric oxide (NO) generated by eNOS in the process of mediating angiogenesis by VEGF. Methods. Tissue sections from 31 patients with MM were examined using immunohistochemistry and morphological quantitative analysis for protein expression of eNOS and VEGF. Microvessel density (MVD) was counted in endothelial cells in immunostained by anti-FVIII:RAg antibody. Results. Positive eNOS and VEGF immunostaining were observed in 77.4% and 83.9% of MM lesions, respectively, whereas pigmented naevi never expessed eNOS and VEGF. A positive correlation between eNOS and VEGF in MM was observed. Expression of eNOS and VEGF was positively correlated with MVD expression in MM, and MVD expression in MM was stronger than in pigmented naevi. Expression of eNOS and VEGF was not correlated with lymph node metastasis. Conclusions. On the basis of the current data showing that malignant melanocytic tumours displayed strong VEGF and eNOS expression, whereas benign melanocytic proliferations showed no immunoreactivity for VEGF and eNOS, such expression may be used as a discriminating factor to distinguish malignant melanoma from pigmented naevi. Expression of eNOS and VEGF may contribute to angiogenesis of MM, eNOS probably plays an important role in mediating VEGF-induced angiogenesis. [ABSTRACT FROM AUTHOR]

A 44-yr climatology of spring Asian dust aerosol emission, column loading, deposition, trans-Pacific transport routes, and budgets during 1960–2003 was simulated with the Northern Aerosol Regional Climate Model (NARCM). Interannual variability in these Asian dust aerosol properties simulated by the model and its climate connections are analyzed with major climatic indices and records in ground observations. For dust production from most of the source regions, the strongest correlations were with the surface wind speed in the source region and the area and intensity indices of the Asian polar vortex (AIAPV and IIAPV, respectively). Dust emission was negatively correlated with precipitation and surface temperatures in spring. The strength of the East Asian monsoon was not found to be directly related to dust production but rather with the transport of dust from the Asian subcontinent. The interannual variability of dust loading and deposition showed similar relations with various climate indices. The correlation of Asian dust loading and deposition with the western Pacific (WP) pattern and Atmospheric Circulation Index (ACI) exhibited contrasting meridional and zonal distributions. AIAPV and IIAPV were strongly correlated with the midlatitude zonal distribution of dust loading and deposition over the Asian subcontinent and the North Pacific. The Pacific–North American (PNA) pattern and Southern Oscillation index (SOI) displayed an opposite correlation pattern of dust loading and deposition in the eastern Pacific, while SOI correlated significantly with dust loading over eastern China and northeast Asia. The Pacific decadal oscillation (PDO) was linked to variations of dust aerosol and deposition not only in the area of the eastern North Pacific and North America but also in the Asian dust source regions. The anomalies of transport flux and its divergence as well as dust column loading were also identified for eight typical El Niño and eight La Niña years. A shift of the trans-Pacific transport path to the north was found for El Niño years, which resulted in less dust storms and dust loading in China. In El Niño years the deserts in Mongolia and western north China closer to the polar cold air regions contributed more dust aerosol in the troposphere, while in La Niña years the deserts in central and eastern north China far from polar cold regions provided more dust aerosol in the troposphere. On the basis of the variability of Asian dust aerosol budgets, the ratio of inflow to North America to the outflow from Asia was found to be correlated negatively with the PNA index and positively with the WP index. [ABSTRACT FROM AUTHOR]

The structure, hydrogen storage property, and electrochemical characteristics of the La0.7Mg0.3Ni5.5-x (Al0.5Mo0.5)x (x = 0, 0.2, 0.4, 0.6, 0.8) hydrogen storage alloys have been investigated systematically. It has been found by X-ray powder diffraction and Rietveld analysis that the alloys are multiphase and consist of impurity Ni phase and two main crystallographic phases, namely, the La(La, Mg)2Ni9 phase and the LaNi5 phase, and the lattice parameters and the cell volumes of both the La(La, Mg)2Ni9 phase and the LaNi5 phase increase with increasing Al and Mo content in the alloys. The P-C isotherm curves indicated that the hydrogen storage capacity of the alloy first increases and then decreases with increasing x, and the equilibrium pressure decreases with increasing x. The electrochemical measurements show that the maximum discharge capacity first increases from 298.5 (x = 0) to 328.3 mAh/g (x = 0.6) and then decreases to 304.7 mAh/g (x = 0.8). The high rate dischargeability (HRD) of the alloy electrodes increases lineally from 65.4 pct (x = 0) to 86.6 pct (x = 0.8) at the discharge current density of 1200 mA/g. Moreover, the exchange current density of the alloy electrodes also increases monotonously with increasing x by the linear polarization curves. The hydrogen diffusion coefficient in the alloy bulk, D, increases with increasing Al and Mo content and thus enhances the low-temperature dischargeability (LTD) of the alloy electrodes. [ABSTRACT FROM AUTHOR]

In engineering applications, dealing with the stress concentrations is an important issue. When a stress concentration presents a non-singular feature, the commonly used engineering strength criteria are usually not appropriate to predict the structure failure. In this paper, we first presented a simple experimentation, which consists of a central-holed plate under uniaxial tensile loading. Then we showed that most of commonly used criteria are not suitable for this case of non-singular stress concentration. By analysing the energy dissipation of micro-crack bands under different stress concentrations, we proposed a new fracture criterion based on the finite fracture mechanics. It was shown that this criterion could provide accurate critical remote loads comparing with experimental data. We believe that the three-parameter concept is physically reasonable and can be used in establishing fracture criteria in both the cases of singular and non-singular stress concentrations. [ABSTRACT FROM AUTHOR]

In view of the possible crosstalks between hematopoiesis and neuropoiesis, we evaluated two microenvironments, murine neonatal neural cell line C17.2 and primary embryonic aorta-gonad-mesonephros (AGM) stromal cells, on the ex vivo expansion of CD34+ cells from human cord blood. In a contact culture system, C17.2 or AGM cells significantly enhanced the expansion of CD34+ cells to a panel of early and committed hematopoietic progenitor cells. In a noncontact transwell system, pre-established C17.2 cells significantly increased the expansion of total nucleated cells, CD34+ cells and multilineage colony forming cells (P<0.01). Expanded cells were infused into nonobese diabetic/severe-combined immunodeficient mice. The engraftment of human (hu)CD45+ cells in the bone marrow of these mice was consistently higher in all the 10 experiments conducted with the support of C17.2 cells when compared with those in respective control groups (11.9 vs 2.43%, P=0.03). Using RT-PCR and Southern blot analysis, we showed that AGM and C17.2 cells expressed a panel of hematopoietic, bone morphogenetic and neurotrophic factors. Our data provided the first evidence on the promoting effects of a neural progenitor cell line on hematopoiesis at a noncontact condition. The mechanism could be mediated by the expression of multilineage regulatory factors.Leukemia (2005) 19, 91-97. doi:10.1038/sj.leu.2403542 Published online 21 October 2004 [ABSTRACT FROM AUTHOR]

Fine titanate nanowires of K[sub 2]Ti[sub 8]O[sub 17] structure with a diameter of 5–10 nm and a typical length of several micrometers to several tens of micrometers have been synthesized hydrothermally via a reaction of titania particles and KOH solution. The growth of nanowires is along the [010] direction. The surface area of nanowires can exceed more than 300 m[sup 2]/g, which is expected to be significant in their applications to catalysis and other fields. Calcination over 600 °C causes K[sub 2]Ti[sub 8]O[sub 17] nanowires to decompose to K[sub 2]Ti[sub 6]O[sub 13] and TiO[sub 2]. [ABSTRACT FROM AUTHOR]

Presents a study that examined cobblestone area-forming cells, long term culture-initiating cells and mouse repopulating cells in neonatal blood (NB). Review of related literature; Background on human hematopoiesis; Analysis of cryopresevation and thawing of neonatal blood and umbilical cord blood; Implications for the use of NB as a source of hematopoietic pluripotent stem cells.

Background: Ex vivo expansion of cord blood (CB) hematopoietic stem and progenitor cells increases cell dose and may reduce the severity and duration of neutropenia and thrombocytopenia after transplantation. This study's purpose was to establish a clinically applicable culture system by investigating the use of cytokines, serum-free media, and autologous plasma for the expansion of CB cells and the engraftment of expanded product in nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice.Study Design and Methods: Enriched CB CD34+ cells were cultured in four media (Iscove's modified Dulbecco's medium with FCS, Gibco; X-Vivo-10, BioWhittaker; QBSF-60, Quality Biological; and StemSpan SFEM, Stem Cell Technologies) with four cytokine combinations (thrombopoietin [TPO], SCF, Flt-3 ligand [FL] with and without G-CSF, and/or IL-6). The effect of autologous CB plasma was also investigated. The read-out measures were evaluated on Days 8 and 12. After expansion at the optimized condition, cultured cells were transplanted into sublethally irradiated NOD/SCID mice. The engraftment of human CD45+ cells and subsets in the bone marrow, spleen, and peripheral blood was determined.Results: QBSF-60 or StemSpan SFEM supported high yields of early progenitors (CD34+ cells, Conclusion: The data supported the strategy of expansion. The optimized condition may be applicable to clinical expansion for the abrogation or reduction of posttransplant cytopenia. [ABSTRACT FROM AUTHOR]

Infusion of ex vivo expanded megakaryocytic (MK) progenitor cells is a strategy for shortening the duration of thrombocytopenia after haematopoietic stem cell transplantation. The cell dose after expansion has emerged as a critical factor for achieving the desired clinical outcomes. This study aimed to establish efficient conditions for the expansion of the MK lineage from enriched CD34+ cells of umbilical cord blood and to investigate the effect of platelet-derived growth factor (PDGF) in this system. Our results demonstrated that thrombopoietin (TPO) alone produced a high proportion of CD61+CD41+ cells but a low total cell count and high cell death, resulting in an inferior expansion. The addition of interleukin-1β (IL-1β), Flt-3 ligand (Flt-3L) and to a lesser extent IL-3 improved the expansion outcome. The treatment groups with three to five cytokines produced efficient expansions of CFU-MK up to 400-fold with the highest yield observed in the presence of TPO, IL-1β, IL-3, IL-6 and Flt-3L. CD34+ cells were expanded by five to 22-fold. PDGF improved the expansion of all cell types with CD61+CD41+ cells, CFU-MK and CD34+ cells increased by 101%, 134% and 70%, respectively. On day 14, the CD61+ population consisted of diploid (86.5%), tetraploid (11.8%) and polyploid (8N–32N; 1.69%) cells. Their levels were not affected by PDGF. TPO, IL-1β, IL-3, IL-6, Flt-3L and PDGF represented an effective cytokine combination for expanding MK progenitors while maintaining a moderate increase of CD34+ cells. This study showed, for the first time, that PDGF enhanced the ex vivo expansion of the MK lineage, without promoting their in vitro maturation. PDGF might be a suitable growth factor to improve the ex vivo expansion of MK progenitors for clinical applications. Bone Marrow Transplantation (2001) 27, 1075–1080. [ABSTRACT FROM AUTHOR]

For preparing a berberine-sensitive electrode, 5,10,15,20-tetrakis[2-(2,3,4,6-tetraacetyl-β-D-glucopyranosyl)-1-O-phenyl]porphyrin (T( o-glu)PPH2) was synthesized from the reaction of pyrrole with ortho-acetylglycosylated benzaldehyde by Lindsay’s method. The electrode based on T( o-glu)PPH2 with an optimized membrane composition exhibits Nernstian response to berberine in the concentration range 2.4 × 10–7–5.0 × 10–3 mol L–1, with a pH range from 3.9 to 10.2, and a fast response time of 30 s. The electrode shows fair selectivity towards berberine with respect to common co-existing species. T( o-glu)PPH2 shows better potentiometric response characteristics comparing to chloro[5,10,15,20-tetrakis[2-(2,3,4,6-tetraacetyl-β-D-glucopyranosyl)-1-O-phenyl]-porphinato]-manganese (MnT( o-glu)PPCl) and better selectivity towards berberine than tetraphenylporphyrin (TPPH2). The effect of the composition of the electrode membrane has been studied and the experimental conditions optimized. The contents of berberine in pharmaceutical tablets were determined by direct potentiometry and the results agreed with values obtained by the pharmacopoeia method. [ABSTRACT FROM AUTHOR]