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Fall is the major risk factor of fracture that has not been included in FRAX®. Whether different age may determine the effect of falls on FRAX® is still uncertain. This epidemiological cohort study reveals that history of fall is a significant predictor of incident fracture independent of FRAX probability, especially in subjects

The ZnO nanorod arrays are grown on the sol–gel-derived seed layer through aqueous chemical growth, and then assembled as gas sensors for detecting carbon monoxide (CO). It is found that the structural and photoluminescent properties of the ZnO nanorod arrays are different as they are grown on seed layers annealed at different temperature (300–700 °C), which is ascribed to distinct growth kinetics of nanorods on the annealed seed layer. Moreover, the correlation between the exposed surface area and the defect density of those ZnO nanorod arrays points out the intrinsic (interior) defects can dominate the green emission instead of surface defects in the present study. Furthermore, the quantities of chemisorbed oxygen on ZnO nanorod arrays can be estimated through XPS analysis. Consequently, the influence of intrinsic defects and chemisorbed oxygen on the electrical properties and gas sensitivities of ZnO nanorod arrays has been clearly elucidated. It is demonstrated that the more adsorbed oxygen and an appropriate amount of intrinsic defects is advantageous to obtain superior CO gas sensitivity for ZnO nanorod arrays.

Earlier, we showed that epidermal growth factor receptor (EGFR) signaling in human glioma cells increased cyclooxygenase-2 (COX-2) expression through p38-mitogen-activated protein kinase (MAPK)-dependent activation of the Sp family of transcription factors. Further mechanistic details of EGFR-dependent induction of COX-2 expression in glioma cells remained elusive. Protein kinase Cs (PKCs) comprise a family of serine-threonine kinases that are major mediators of signaling from receptor tyrosine kinases. Here, we report that PKC-delta, a novel PKC isoform, plays a role in EGF-dependent COX-2 induction in human glioma cells. Pharmacological inhibition and genetic silencing (through siRNA or dominant-negative expression) of PKC-delta confirm a role for this PKC isoform in EGF-dependent COX-2 induction. Overexpression of a functional PKC-delta enhanced COX-2 expression indicating that PKC-delta is not only necessary but also sufficient to regulate COX-2 levels. Inhibition of p38-MAPK pharmacologically or with siRNA further shows that p38-MAPK is required for activation of PKC-delta by EGF while inhibition of PKC-delta had no discernible effects on p38-MAPK activation. Finally, EGF stimulation promotes physical interactions between PKC-delta and Sp1 resulting in phosphorylation and nuclear localization of this transcription factor. These data provide the first evidence that PKC-delta is a critical link between p38-MAPK and Sp1-dependent COX-2 expression in human glioma cells.

RNA interference (RNAi) was reported to block hepatitis B virus (HBV) gene expression and replication in vitro and in vivo. However, it remains a technical challenge for RNAi-based therapy to achieve long-term and complete inhibition effects in chronic HBV infection, which presumably requires more extensive and uniform transduction of the whole infected hepatocytes. To increase the in vivo transfection efficiency in liver, we used a double-stranded adeno-associated virus 8-pseudotyped vector (dsAAV2/8) to deliver shRNA. HBV transgenic mice were used as an animal model to evaluate the inhibition effects of the RNAi-based gene therapy. A single administration of dsAAV2/8 vector, carrying HBV-specific shRNA, effectively suppressed the steady level of HBV protein, mRNA and replicative DNA in liver of HBV transgenic mice, leading to up to 2-3 log(10) decrease in HBV load in the circulation. Significant HBV suppression sustained for at least 120 days after vector administration. The therapeutic effect of shRNA was target sequence dependent and did not involve activation of interferon. These results underscore the potential for developing RNAi-based therapy by dsAAV2/8 vector to treat HBV chronic infection, and possibly other persistent liver infections as well.

Many investigations and researches studied the reaction ability between high explosive RDX and RDX with other chemicals. However, accidents still occur and operating problems exist among the RDX manufacturing process. This study utilized inherent safety concepts and DSC thermal analysis to assess the incompatible reaction hazards of RDX during usage, handling, storage, transporting and manufacturing. This assessment includes thermal curve observations and kinetic evaluations. A decomposition mechanism of the incompatible reaction is proposed. Among all the contaminants evaluated in this study, the existence of ferrous chloride tetrahydrate, ferric chloride hexahydrate and nitric acid shifted the main endothermic and exothermic reactions of RDX. These contaminants further advanced the exothermic temperature onset average by about 53, 46 and 61°C, respectively. The summarized results suggest that ferric oxide, ferrous chloride tetrahydrate, ferric chloride hexahydrate, acetone solution and nitric acid can influence the reaction and thermokinetic properties of RDX. These chemicals could induce potential hazards by causing temperature control instability, heating and cooling systems failure, and produce an unexpected secondary explosion. According to the conclusions of this study, potential incompatible RDX hazards during usage and manufacturing could be avoided.

The joint strength and fracture surface of Pb/Sn and Au/Sn solders in laser-diode packages after thermal-aging testing were studied experimentally. Specimens were aged at 150°C for up to 49 days. The joint strength decreased as aging time increased. The microstructure and fracture surface of the Pb/Sn and Au/Sn solder joints showed that the joint strength decrease was caused by both the enlargement of the initial voids and an increase in the number of voids as aging time increased. The formation of Kirkendall voids with intermetallic-compound (IMC) growth of the Pn/Sn solder as aging time increased was also a possible mechanism for the joint-strength reduction. Finite-element method (FEM) simulations were performed on the joint-strength estimation of Pb/Sn and Au/Sn solders in thermal-aging tests. The coupled thermal-elasticity-plasticity model was used to simulate distributions of the thermal and residual stresses, creep deformation, and joint-strength variations in the solder joints under various thermal-aging tests. Simulation results were in good agreement with the experimental measurements that the solder-joint strength decreased as aging time increased. The result suggests that the FEM is an effective method for analyzing and predicting the solder-joint strength in laser-diode packages.

Bax causes apoptosis by associating with mitochondria and triggering cytochrome c release, which activates the caspase cascade. Bax can also kill some cells independently of caspases, but the requirements for such killing are poorly understood. Here we describe an inducible fibroblast line that expresses Bax when tetracycline is withdrawn; the resulting apoptosis can be blocked by the caspase inhibitor zVAD-fmk. Even when caspases are inhibited, however, treating the Bax-expressing cells with the mitochondrial toxin oligomycin efficiently triggers death with features resembling apoptosis. Bax mutants lacking the BH3 domain remain able to cause cytochrome c release and caspase-mediated death, but cannot support this caspase-independent killing. Mutating specific BH3 residues needed for binding Bcl2 does not prevent synergy with oligomycin, implying that no such binding is required. These findings illuminate a caspase-independent pathway of death that depends on the Bax BH3 domain and on effectors emanating from mitochondria.

The inability to economically separate Fe3+(aq) from a variety of liquid effluents is a major concern for the primary metals industry. A unique solvent extraction process, galvanic stripping, has been developed to address this problem. The galvanic stripping of iron from D2EHPA using only a 5≈10 g/L H2SO4 solution is achieved after Fe3+ is directly reduced to Fe2+ in the organic phase using zinc metal additions. To date, the primary focus of the laboratory research has been on optimizing the parameters that control iron removal. The results from these studies have now been used to make a preliminary design for a continuous flow process that is envisioned for zinc industrial applications. Specific quantitative data are shown for the use of a Zn-Pb alloy in the iron-removal process. Some introductory results on electrochemical potential measurements and impurity distribution with solution cycling are also given.

Cytomegalovirus infection is usually reported inimmunocompromised patients. In this study, apparentlyimmunocompetent patients with cytomegaloviral colitiswere reviewed. Records with a diagnosis ofcytomegaloviral colitis from January 1989 to June 1996 wereretrieved for analysis. Ten patients were included(median age 70 yr). The major presenting symptoms werediarrhea and hematochezia. Ulceration was the mainmacroscopic finding. Rectal bleeding was mostlyself-limiting. Three patients developed localcomplications (rectovaginal fistula in two; rectalstricture in one). In the two patients with rectovaginalfistula, lymphocytes subsets and proliferative response wereentirely normal. In the other patient, low B lymphocytecount and low response to mitogen were demonstrated.However, the immunoglobulins were not suppressed and rectal biopsies revealed noncaseatinggranulomas, suggesting activated cell-mediated immunity.In conclusion, a high index of suspicion is crucial forearly diagnosis of cytomegaloviral colitis in patients with bloody diarrhea, even though obviousevidence of immunodeficiency is lacking.

Differential display of mRNA (DD) is a technique in which mRNA species expressed by a cell population are reverse transcribed and then amplified by many separate polymerase chain reactions (PCR). PCR primers and conditions are chosen so that any given reaction yields a limited number of amplified cDNA fragments, permitting their visualization as discrete bands following gel electrophoresis. This robust and relatively simple procedure allows identification of genes that are differentially expressed in different cell populations. Here we review DD including some recent modifications, and compare it with other techniques for analyzing differential mRNA expression.

It has been observed that the field biodegradation rates for soluble hydrocarbon plumes are significantly smaller than the aerobic rates observed in the laboratory. It is believed that this difference is related to the fact that in the field oxygen and hydrocarbon must be mixed before the biodegradation reaction can occur, and that the effective degradation rate is controlled by the actual, not mean, concentrations of oxygen and hydrocarbon. In this work, we present a conceptual model of oxygen-mixing limited biodegradation, which indicates that the effective degradation rate should depend on the cross correlation between the oxygen and hydrocarbon concentration fluctuations. This is followed by a development of a rigorous, field-scale model.

The first paper (Chang et al., 1995b) of this two-part series described the stochastic analysis using spectral/perturbation approach to analyze steady state two-phase (water and oil) flow in a, liquid-unsaturated, three fluid-phase porous medium. In this paper, the results between the numerical simulations and closed-form expressions obtained using the perturbation approach are compared. We present the solution to the one-dimensional, steady-state oil and water flow equations. The stochastic input processes are the spatially correlated logk where k is the intrinsic permeability and the soil retention parameter, α. These solutions are subsequently used in the numerical simulations to estimate the statistical properties of the key output processes. The comparison between the results of the perturbation analysis and numerical simulations showed a good agreement between the two methods over a wide range of logk variability with three different combinations of input stochastic processes of logk and soil parameter α. The results clearly demonstrated the importance of considering the spatial variability of key subsurface properties under a variety of physical scenarios. The variability of both capillary pressure and saturation is affected by the type of input stochastic process used to represent the spatial variability. The results also demonstrated the applicability of perturbation theory in predicting the system variability and defining effective fluid properties through the ergodic assumption.

Within the framework of stochastic theory and the spectral perturbation techniques, three-dimensional dispersion in partially saturated soils with fractal log hydraulic conductivity distribution is analyzed. Our analysis is focused on the impact of fractal dimension of log hydraulic conductivity distribution, local dispersivity, and unsaturated flow parameters, such as the soil poresize distribution parameter and the moisture distribution parameter, on the spreading behavior of solute plume and the concentration variance. Approximate analytical solutions to the stochastic partial differential equations are derived for the variance of asymptotic solute concentration and asymptotic macrodispersivities.

Stochastic analysis of steady-state multiphase (water, oil, and air) flow in heterogeneous porous media was performed using the perturbation theory and spectral representation techniques. The gas phase is assumed to have constant pressure. The governing equations describing the flow of oil and water are coupled and nonlinear. The key stochastic input variables are intrinsic permeability,k, and the soil grain size distribution index, α. Three different stochastic combinations of these two input parameters were considered. The perturbation/spectral analysis was used to develop closed-form expressions that describe stochastic variability of key output processes, such as capillary and individual phase pressures and specific discharges. The analysis also included the derivation of the mean flow equations and estimation of the effective flow properties. The impact of the spatial variability ofk and α on the effective conductivities and the variances of pressures and specific discharges was examined.

In this article, we are concerned with the statistics of steady unsaturated flow in soils with a fractal hydraulic conductivity distribution. It is assumed that the spatial distribution of log hydraulic conductivity can be described as an isotropic stochastic fractal process. The impact of the fractal dimension of this process, the soil pore-size distribution parameter, and the characteristic length scale on the variances of tension head and the effective conductivity is investigated. Results are obtained for one-dimensional and three-dimensional flows. Our results indicate that the tension head variance is scale-dependent for fractal distribution of hydraulic conductivity. Both tension head variance and effective hydraulic conductivity depend strongly on the fractal dimension. The soil pore-size distribution parameter is important in reducing the variability of the unsaturated hydraulic conductivity and of the fluxes.

Optical reflectance of YBa2Cu3O7-δ thin films grown by laser ablation is measured within photon energies of 0.1 eV to 3.5 eV at room temperature. The spectra can be fit congruently with the anisotropic dielectric constants which take account of the intraband free carrier transition and interband transition. The anisotropic plasma frequencies are simulated to be ħepl=2.18 eV and ħech=2.80 eV contributed from free carriers on the plane and in the chain, respectively. The interband transition occurs near 2.5 eV and is pertinent to a rather broad line width.

Evidence is presented to indicate that there exists in lymphoid tissue, as a result of transforming lymphocytes, a new lymphokine which is chemotactically specific for lymphocytes, called 'lymphotactin'. Lymphotactin has been purified to electrophoretic homogeneity; has a molecular weight of 10,500 D and an isoelectric point of 5.9. Its role in amplifying the immune defense system by recruitment of naive lymphocytes into propinquity with the challenging antigens is suggested. Purification of macrophage migration inhibitory factor from thymus extracts to electrophoretic homogeneity leads to a compound of molecular weight of 36,500 D and an IEP of 6.9. Chemically it contains sialic acid and o-methyl glucopyranoside as its only carbohydrates. Purified MIF activates the macrophage phagocytically. Skin reactive factor and lymph node permeability factor have been isolated and purified and are found to be inhibited by pepstatin and antihistamine and to have an isoelectric point of pH 4.2 and a molecular weight of 50,000--100,000 D. It is believed that this anionic permeability increasing agent actually arises from the lysosomes of macrophages and lymphoblasts (the normal small lymphocyte having essentially no lysosomal organelles). The mononuclear cell infiltration characteristic of crude SRF and LNPF may proceed from their being contaminated with lymphotactin.