2,198 research outputs found

    Comparison of pain relief among patients with chronic plantar fasciitis treated with intralesional platelet-rich plasma injection versus corticosteroid injection in a tertiary care centre in Kerala - a prospective study

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    Background: Aim of the study was to compare pain relief and functional outcome and between intralesional autologous platelet rich plasma injection (PRP) versus corticosteroid injection in the treatment of plantar, and fasciitis by using visual analogue score and American Orthopaedic Foot and Ankle Society (AOFAS) score. Methods: The sample size for the study was 30 patients attending Dr. Somervell Memorial CSI Medical College. Patients were divided into two groups (PRP versus steroid) of 15 each. The study follows a prospective observational design with follow up at 2 weeks, 2 months and 3 months post procedure. The functional outcome of patients in each group was assessed using the visual analog scale and AOFAS score. Results: Post-procedure, a significant decrease in VAS score was seen in patients treated with PRP injection (8.73 to 2.27) than those treated with Steroid injection (8.8 to 3.53). Also, there was a significant improvement in the AOFAS score from 72.73 to 88.67 while for those patients treated with steroid injection, the AOFAS score was comparatively low (65.87 to 82.2). Conclusions: Plantar fasciitis is a prevalent condition in our community, and many treatment options typically offer only temporary relief from symptoms. Intralesional PRP injection emerges as a dependable treatment method that fosters the healing process of the affected fascia, resulting in improved functional outcomes. Our study indicates that a singular administration of platelet-rich plasma injection for plantar fasciitis yields substantial pain relief compared to the local steroid injection

    On the dynamic tensile strength of Zirconium

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    Despite its fundamental nature, the process of dynamic tensile failure (spall) is poorly understood. Spall initiation via cracks, voids, etc, before subsequent coalesce, is known to be highly microstructure-dependant. In particular, the availability of slip planes and other methods of plastic deformation controls the onset (or lack thereof) of spall. While studies have been undertaken into the spall response of BCC and FCC materials, less attention has paid to the spall response of highly anisotropic HCP materials. Here the dynamic behaviour of zirconium is investigated via plate-impact experiments, with the aim of building on an ongoing in-house body of work investigating these highly complex materials. In particular, in this paper the effect of impact stress on spall in a commercially sourced Zr rod is considered, with apparent strain-rate softening highlighted

    The Discovery of a Giant H-alpha Filament in NGC 7213

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    The nearby Seyfert galaxy NGC 7213 has been imaged in H-alpha and HI with the CTIO 1.5 m telescope and with the Australia Telescope Compact Array (ATCA), respectively. Optically NGC 7213 looks undisturbed and relatively featureless but the continuum-subtracted H-alpha image shows a 19 kpc long filament located approximately 18.6 kpc from the nucleus. The H-alpha filament could be neutral gas photo-ionized by the active nucleus, as has been suggested for the Seyfert galaxy NGC 5252, or shock-ionized by a jet interacting with the surrounding HI, as has been suggested for the radio galaxy PKS 2240-41. The HI map reveals NGC 7213 to be a highly disturbed system suggesting a past merging event.Comment: 14 pages including 4 figures and 1 table. Figures 1-4 are in jpeg format; Better quality images can be retrieved in postscript format at ftp://charon.nmsu.edu/pub/shameed/ ; Accepted for publication in ApJ Letter

    Design and Simulation of Two Stage Wideband CMOS Amplifier in 90 NM Technology

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    Design and simulation of 7 GHz CMOS wideband amplifier(CMOSWA) using a modified cascode circuit realized in  90-nm CMOS technology is presented here. The proposed system consists of two stages, namely a modified folded cascode and an inductively degenerated common source amplifier. The circuit is experimented with and without a feedback network. This work discusses the performance variation as a function of reactive components, and the initial stage results in 22 dB gain,2.6 GHz bandwidth, and 40GHz unity gain-bandwidth. The circuit without the feedback network exhibits 30.7dB gain,4.8GHz bandwidth(BW), and 10GHz unity-gain bandwidth(UGB). The reactive feedback network's inclusion helped to achieve 38.7 dB gain, 6.95GHz BW, 30GHz UGB, and 55o phase margin. The circuit consumes 1.4mW power from a 1.8V power supply. Simulation results of the proposed circuit are comparable and better than the reported wideband designs in the literature. Realization of our proposed circuit would add value to the area of wideband amplifier design

    The Rate-Controlled Constrained-Equilibrium Approach to Far-From-Local-Equilibrium Thermodynamics

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    The Rate-Controlled Constrained-Equilibrium (RCCE) method for the description of the time-dependent behavior of dynamical systems in non-equilibrium states is a general, effective, physically based method for model order reduction that was originally developed in the framework of thermodynamics and chemical kinetics. A generalized mathematical formulation is presented here that allows including nonlinear constraints in non-local equilibrium systems characterized by the existence of a non-increasing Lyapunov functional under the system’s internal dynamics. The generalized formulation of RCCE enables to clarify the essentials of the method and the built-in general feature of thermodynamic consistency in the chemical kinetics context. In this paper, we work out the details of the method in a generalized mathematical-physics framework, but for definiteness we detail its well-known implementation in the traditional chemical kinetics framework. We detail proofs and spell out explicit functional dependences so as to bring out and clarify each underlying assumption of the method. In the standard context of chemical kinetics of ideal gas mixtures, we discuss the relations between the validity of the detailed balance condition off-equilibrium and the thermodynamic consistency of the method. We also discuss two examples of RCCE gas-phase combustion calculations to emphasize the constraint-dependent performance of the RCCE method.Fondazione Cariplo (grant 2008-2290)United States. Army Research Office (grant number W911NF-08-1-0444

    Sequence analysis of the rifampicin resistance determining region (RRDR) of rpoB gene in multidrug resistance confirmed and newly diagnosed tuberculosis patients of Punjab, Pakistan

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    Molecular screening of new patients suspected for TB could help in the effective control of TB in Pakistan as it is a high TB burden country. It will be informative to understand the prevalence of multi drug resistance for a better drug regimen management in this geographical area. The Rifampicin resistance determining region (RRDR) sequencing was used to identify mutations associated with drug resistance in DNA extracts from 130 known multidrug resistant (MDR) cultured strains and compared with mutations observed in DNA extracts directly from 86 sputum samples from consecutive newly diagnosed cases in Lahore, Pakistan. These newly diagnosed samples were positive for smear microscopy, chest X-ray and presumed sensitive to first line drugs. In the known MDR group the most frequent mutations conferring resistance were found in rpoB531 (n = 51, 39.2%). In the newly diagnosed tuberculosis group with no history of MDR, mutations in rpoB531 were seen in 10 of the samples (11.6%). Collectively, all mutations in the RRDR region studied were observed in 80 (61.5%) of known MDR cases and in 14 (16.3%) of the newly diagnosed cases. Using the RRDR as a surrogate marker for MDR, sequences for the newly diagnosed (presumed sensitive) group indicate much higher levels of MDR than the 3.9% WHO 2015 global estimate and suggests that molecular screening directly from sputum is urgently required to effectively address the detection and treatment gaps to combat MDR in this high burden country

    Characterization and Classification of Brain Tissue and Stroke Lesions in Non-Contrast Computed Tomography Images of Stroke Patients Using Statistical Texture Descriptors and Artificial Neural Network

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      Aim: To characterize and classify stroke lesions and normal brain tissue in computed tomography (CT) images using statistical texture descriptors. Patients and methods: Two experienced radiologists blinded to each other inspected CT images of 164 stroke patients to identify and categorize stroke lesions into ischaemic and haemorrhagic subtypes. Four regions of interest (ROIs) in each CT slice that demonstrated the lesion; two each representing the lesion and normal tissue were selected. Statistical texture descriptors namely, co-occurrence matrix, run-length matrix, absolute gradient and histogram were calculated for them.  Raw data analysis was performed to identify the parameters that best discriminate between normal brain tissue and stroke lesions. Artificial neural network (ANN) was used to classify the ROIs into normal tissue, ischaemic and haemorrhagic lesions using the radiologists’ identification and categorization as the gold standard, and further analyzed using the receiver operating characteristic curve. Results: Three parameters in each texture class discriminated between normal tissue, ischaemic and haemorrhagic stroke lesions. The discriminating co-occurrence matrix parameters were sum average parameters namely S1-1 SumAverg, S1-0 SumAverg and S0-1 SumAverg.  For the run-length matrix, short run emphasis in horizontal, 1350 and 450 directions were the discriminating features. The discriminating absolute gradient parameters were gradient non-zeros, gradient variance and gradient mean. For the histogram class, the mean, 90th and 99th percentiles were the discriminating parameters. The ANN achieved a sensitivity of 0.637, specificity 0.753, false positive rate (FPR) 0.247, and false negative rate (FNR) 0.363 with co-occurrence matrix. With run-length matrix the sensitivity was 0.544, specificity 0.607, FPR 0.393, and FNR 0.456 while with absolute gradient the sensitivity was 0.546, specificity 0.586, FPR 0.414, FNR 0.454. With histogram, the sensitivity was 0.947, specificity 0.962, FPR 0.038, and FNR 0.053. Conclusion: The histogram texture features showed the highest sensitivity and specificity in the classification of brain tissue and stroke lesions using the artificial neural network.    &nbsp

    On the effects of powder morphology on the post-comminution ballistic strength of ceramics

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    In this paper in order to try and elucidate the effects of particle morphology on ballistic response of comminuted systems, a series of experiments were carried out via the use of powder compacts with differing initial particle morphologies. This approach provided a route to readily manufacture comminuted armour analogues with significantly different microstructural compositions. In this study pre-formed `fragmented-ceramic' analogues were cold-pressed using plasma-spray alumina powders with two differing initial morphologies (angular and spherical). These compacts were then impacted using 7.62-mm FFV AP (Förenade Fabriksverken Armour Piercing) rounds with the subsequent depth-of-penetration of the impacting projectile into backing Al 6082 blocks used to provide a measure of pressed ceramic ballistic response. When material areal density was accounted for via differing ballistic efficiency calculations a strong indication of particle morphology influence on post-impact ceramic properties was apparent. These results were reinforced by a separate small series of plate-impact experiments, whose results indicated that powder morphology had a strong influence on the nature of compact collapse

    Determination of residual stress distributions in autofrettaged thick cylinders

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    High pressure vessels such as gun barrels are autofrettaged in order to increase their operating pressure and fatigue life. Autofrettage causes plastic expansion of the inner section of the cylinder – setting up residual compressive stresses at the bore after relaxation. Subsequent application of pressure has to overcome these compressive stresses before tensile stresses can be developed, thereby increasing its fatigue lifetime and safe working pressure. A series of Finite Element (FE) models of hydraulic autofrettage were created, to establish the correct boundary conditions required and means of developing accurate but computationally efficient models. Close agreement was observed between the solutions obtained from the developed models and those from existing analytical and numerical models. These initial models used a simplistic bi- linear stress-strain material representation; this deficiency was then addressed through the development of two means of creating radial position dependent non-linear material behaviour within FE, crucial for accurate prediction of residual stresses. The first utilised a method of altering the elastic properties of the material to achieve nonlinear stress-strain response. This provided accurate results that compared well with existing methods, but was unable to be used in simulation of swage autofrettage due to its elastic nature. The second method achieved non- linear behaviour through direct manipulation of the stress and plastic strain states of the FE model at a fundamental level. This was hence suitable for arbitrary loading procedures, including swage autofrettage. A swage-like model that applied deformation via a band of pressure was developed, to investigate the influence of localised loading and shear stresses that result on the residual stress field. A full model of swage autofrettage was then developed, which was optimised on the basis of accuracy and solution effort. It was then used to investigate the effects of various mandrel and contact parameters on the creation of residual stresses. The model is suitable for use in future optimisation studies of the swage autofrettage procedure.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
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