63 research outputs found
Unicompartmental knee arthroplasty in patients aged less than 65: Combined data from the Australian and Swedish Knee Registries
Introduction and purpose: In recent years, there has been renewed interest in using unicompartmental knee arthroplasty (UKA). Several studies have reported increasing numbers of UKAs for osteoarthritis in patients who are less than 65 years of age, with low revision rates. To describe and compare the use and outcome of UKA in this age group, we have combined data from the Australian and Swedish knee registries. Patients and methods: More than 34,000 UKA procedures carried out between 1998 and 2007 were analyzed, and we focused on over 16,000 patients younger than 65 years to determine usage and to determine differences in the revision rate. Survival analysis was used to determine outcomes of revision related to age and sex, using any reason for revision as the endpoint. Results: Both countries showed a decreasing use of UKA in recent years in terms of the proportion of knee replacements and absolute numbers undertaken per year. The 7-year cumulative risk of revision of UKA in patients younger than 65 years was similar in the two countries. Patients younger than 55 years had a statistically significantly higher cumulative risk of revision than patients aged 55 to 64 years (19% and 12%, respectively at 7 years). The risk of revision in patients less than 65 years of age was similar in both sexes. Interpretation: The results of the combined UKA data from the Australian and Swedish registries show a uniformity of outcome between countries with patients aged less than 65 having a higher rate of revision than patients who were 65 or older. Surgeons and patients should be aware of the higher risk of revision in this age group.Annette W-Dahl, Otto Robertsson, Lars Lidgren, Lisa Miller, David Davidson, Stephen Graves
Ethylene supports colonization of plant roots by the mutualistic fungus Piriformospora indica
The mutualistic basidiomycete Piriformospora indica colonizes roots of mono- and dicotyledonous plants, and thereby improves plant health and yield. Given the capability of P. indica to colonize a broad range of hosts, it must be anticipated that the fungus has evolved efficient strategies to overcome plant immunity and to establish a proper environment for nutrient acquisition and reproduction. Global gene expression studies in barley identified various ethylene synthesis and signaling components that were differentially regulated in P. indica-colonized roots. Based on these findings we examined the impact of ethylene in the symbiotic association. The data presented here suggest that P. indica induces ethylene synthesis in barley and Arabidopsis roots during colonization. Moreover, impaired ethylene signaling resulted in reduced root colonization, Arabidopsis mutants exhibiting constitutive ethylene signaling, -synthesis or ethylene-related defense were hyper-susceptible to P. indica. Our data suggest that ethylene signaling is required for symbiotic root colonization by P. indica
Global analysis of gene expression in NGF-deprived sympathetic neurons identifies molecular pathways associated with cell death
Developing sympathetic neurons depend on nerve growth factor (NGF) for survival and die by apoptosis after NGF withdrawal. This process requires de novo gene expression but only a small number of genes induced by NGF deprivation have been identified so far, either by a candidate gene approach or in mRNA differential display experiments. This is partly because it is difficult to obtain large numbers of sympathetic neurons for in vitro studies. Here, we describe for the first time, how advances in gene microarray technology have allowed us to investigate the expression of all known genes in sympathetic neurons cultured in the presence and absence of NGF
Effects of biofertilizer containing N-fixer, P and K solubilizers and AM fungi on maize growth: A greenhouse trial.
An in vitro study was undertaken to evaluate the compatibility of indigenous plant growth promoting rhizobacteria (PGPR) with commonly used inorganic and organic sources of fertilizers in tea plantations. The nitrogenous, phosphatic and potash fertilizers used for this study were urea, rock phosphate and muriate of potash, respectively. The organic sources of fertilizers neem cake, composted coir pith and vermicompost were also used. PGPRs such as nitrogen fixer; Azospirillum lipoferum, Phosphate Solubilizing Bacteria (PSB); Pseudomonas putida, Potassium Solubilizing Bacteria (KSB); Burkholderia cepacia and Pseudomonas putida were used for compatibility study. Results were indicated that PGPRs preferred the coir pith and they proved their higher colony establishment in the formulation except Azospirillum spp. that preferred vermicompost for their establishment. The optimum dose of neem cake powder
The modular systems biology approach to investigate the control of apoptosis in Alzheimer's disease neurodegeneration
Apoptosis is a programmed cell death that plays a critical role during the development of the nervous system and in many chronic neurodegenerative diseases, including Alzheimer's disease (AD). This pathology, characterized by a progressive degeneration of cholinergic function resulting in a remarkable cognitive decline, is the most common form of dementia with high social and economic impact. Current therapies of AD are only symptomatic, therefore the need to elucidate the mechanisms underlying the onset and progression of the disease is surely needed in order to develop effective pharmacological therapies. Because of its pivotal role in neuronal cell death, apoptosis has been considered one of the most appealing therapeutic targets, however, due to the complexity of the molecular mechanisms involving the various triggering events and the many signaling cascades leading to cell death, a comprehensive understanding of this process is still lacking. Modular systems biology is a very effective strategy in organizing information about complex biological processes and deriving modular and mathematical models that greatly simplify the identification of key steps of a given process. This review aims at describing the main steps underlying the strategy of modular systems biology and briefly summarizes how this approach has been successfully applied for cell cycle studies. Moreover, after giving an overview of the many molecular mechanisms underlying apoptosis in AD, we present both a modular and a molecular model of neuronal apoptosis that suggest new insights on neuroprotection for this disease
Experimental Studies on High-Pressure Spray Structure of Biofuels
The high-pressure spray characteristics of biofuels, specifically, Pongamia oil and its blends with diesel are studied for various gas pressures. Two single-hole solenoid injectors with nozzle diameters of 200 and 260 mu m are used along with a high-pressure common-rail direct-injection system to inject fuel into a high-pressure spray visualization chamber. The spray structure is characterized using a high-speed laser-based shadowgraphy technique. The spray structure of Pongamia oil revealed the presence of an intact liquid core at low gas pressure. At high gas pressures, the spray atomization of the Pongamia oil showed marked improvement. The spray tip penetration of Pongamia oil and its blends with diesel is higher compared to that of diesel for all test conditions. The spray cone angle of Pongamia oil and 50% Pongamia oil blend with diesel is lower as compared to that of diesel. Both these observations are attributed to the presence of large droplets carrying higher momentum in oil and blend. The droplet size is measured at an injection pressure of 1000 bar and gas pressure of 30 bar at 25 mm below the nozzle tip using the particle/droplet image.analysis (PDIA) method. The droplet size measurements have shown that the Sauter mean diameter (SMD) in the spray core of Pongamia oil is more than twice that of diesel. The spray tip penetration of the 20% blend of Pongamia with diesel (P20) is similar to that of diesel but the SMD is 50% higher. Based on experimental data, appropriate spray tip penetration correlation is proposed for the vegetable oil fuels such as Pongamia
A method for measurement of planar liquid volume fraction in dense sprays
A methodology for measurement of planar liquid volume fraction in dense sprays using a combination of Planar Laser-Induced Fluorescence (PLIF) and Particle/Droplet Imaging Analysis (PDIA) is presented in this work. The PLIF images are corrected for loss of signal intensity due to laser sheet scattering, absorption and auto-absorption. The key aspect of this work pertains to simultaneously solving the equations involving the corrected PLIF signal and liquid volume fraction. From this, a quantitative estimate of the planar liquid volume fraction is obtained. The corrected PLIF signal and the corrected planar Mie scattering can be also used together to obtain the Sauter Mean Diameter (SMD) distribution by using data from the PDIA technique at a particular location for calibration. This methodology is applied to non-evaporating sprays of diesel and a more viscous pure plant oil at an injection pressure of 1000 bar and a gas pressure of 30 bar in a high pressure chamber. These two fuels are selected since their viscosity values are very different with a consequently very different spray structure. The spatial distribution of liquid volume fraction and SMD is obtained for two fuels. The proposed method is validated by comparing liquid volume fraction obtained by the current method with data from PDIA technique. (C) 2012 Elsevier Inc. All rights reserved
Multidimensional modelling of flow through piston-controlled ports using a multi-block, moving mesh algorithm
In the present work, a complete algorithm is presented to simulate the gas exchange process across domains in a multi-block computation involving a piston-controlled port. The moving boundary scheme of Peric is used in conjunction with the zonal boundary scheme of Rai. The algorithm has been applied to two cases. The first case involves a typical air-filling process through the piston-operated port of a pneumatic pump, and the analysis shows that flowfield variable information is smoothly communicated across the zonal boundary using this algorithm. The second case involves modelling of the scavenging process in a loop-scavenged two-stroke internal combustion (IC) engine. In this case, the stepwise evolution of the scavenging flow in the engine cylinder is studied. Initiation of short circuiting at early stages of scavenging, tilting of the inlet flow in directions different from inlet port angles and the existence of a low-purity swirling loop in the exhaust-side top corner of the engine cylinder are observed from the flowfield computations
Cu1-xInxSe2 thin films: Deposition by spray pyrolysis and characteristics
Deposition of copper indium selenide (Cu1-xInxSe2 (0 <= x <= 1)) thin films onto the spectroscopic grade amorphous glass substrates was carried out by a chemical spray deposition technique. The deposition parameters, viz. temperature (400 degrees C), time (8 min), solution spray rate (5 ml/min), nozzle to substrate distance (30 cm), air pressure (1.2 kg/m(2)), etc. were optimized so as to obtain good quality samples. The chemical composition and structure of these as-deposited films were determined by the EDS and XRD analyses techniques. The films are nonstoichiometric. Copper and indium contents in the films vary in proportion with the x and 1 x values. Selenium content in the films (for low In-concentration) was less than that of the expected (50%) whereas it exceeds 50% for higher In-concentration in the films. The crystal structure of these films as-revealed by an X-ray diffraction technique showed that the deposits are composites of the CuSe2, CuInSe2, and In2Se3 phases. The observed data have fair match with the JCPD data. The optical studies conducted in the range of wavelengths between 300 nm and 1300 nm showed absorption coefficient of the order of 10(4)-10(5) cm(-1) and the transitions to be of the direct type. The energy band gap decreased continuously from 2.10 eV to 1.15 eV as x was varied from 0 to I. The surface morphology revealed a web of needle like long and tapered at one end, randomly oriented crystallites. Some globule like overgrowth has also been observed. The electrical conductivity studies showed that the films are semiconducting in nature and conductivity is found to be increased with increasing In-content up to x = 0.4 and decreased thereafter. A highest electrical conductivity of 1.1 x 10(-4) (Omega cm) has been observed for the films with x = 0.4. The activation energies of an electrical conduction were then determined for these samples. Thermo power measurements showed same trend of variations analogous to the electrical conductivity and the samples exhibit n as well as p-type conduction. (C) 2012 Elsevier Ltd. All rights reserved
On the surface morphology and transport properties of chemical bath deposited Co(x)Cd1-xS thin films: A correlation
CoxCd1-xS (0 <= x <= 0.5) thin composite films were grown onto glass micro slides from an aqueous alkaline medium using a chemical bath deposition process. A complex liquid phase was formed by the addition of equimolar (1 M) volumes of cadmium sulphate, thiourea and cobaltous sulphate. For deposition, various preparative parameters, viz., speed, temperature, pH, and time were selected as optimized earlier. The chemical composition and surface morphology of these films were determined by an Energy Dispersive Spectroscopy (EDS) and the Scanning Electron Microscopy (SEM), respectively. EDS revealed the film composites to be Cd-rich. SEM revealed polycrystalline randomly oriented crystallites of elongated rhomboids with sharp and clear edges having leaf like appearance (up to x = 0.1). Optical studies revealed that the absorption increased with the increase of Co content in CdS lattice. The strong absorption edge also shifted towards the longer wavelength side and hence the band gap of the materials decreased with the increase of Co content. The temperature and composition dependence of electrical conductivity and thermoelectric power were studied and analyzed to determine the characteristic film properties and to understand the mechanism of an electrical conduction. A continuous decrease in electrical conductivity has been observed when x was varied from 0 to 0.5. The thermo power measurements showed n-type conduction. The observed results are interpreted and supported by the microscopic observations on these films. (C) 2013 Published by Elsevier Ltd
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