101 research outputs found

    Tc-99m NIDP and Tc-99m HMPAO labelled leukocyte scans in tuberculous spondylitis

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    A study was undertaken to assess the pattern of uptake on bone and labelled leukocyte scans in tuberculous spondylitis. Nine consecutive newly diagnosed cases were studied with Tc-99m MDP bone scans and Tc-99m HMPAO labelled leukocyte scans.The patients had basic laboratory investigations, plain chest and spine radiographs and computed tomography of the spine. Static images of bone scans were acquired at 3 hours and labelled leukocyte scans were acquired at 1,3 and 24 hours post-injection. A total of 11 spinal lesions were detected. Six bone scans were done demonstrating eight lesions and all showed abnormally increased activity.Labelled leukocyte scans were done in eight patients involving ten lesions and all except one showed photopaenic defects at the regions of interest.Both bone scan and leukocyte scan provided important information about the extent of the lesions and the combination of their pattern of uptake helped in the diagnosis of tuberculous spondylitis

    Numerical Analysis of Single Edge Notched Tension Specimen With Fatigue Crack Parameter of Conventional Specimen Using Linear Elastic Fracture Mechanics

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    This paper describes the numerical analysis of planar crack growth in high strength steel API 5L X70 whose crack growth parameter is adopted from experimental compact tension (CT) specimen in previous literature. Apart from the fact that conventional fatigue crack growth specimen has bogus geometry constraints, the Single Edge Notched Tension (SENT) better replicate the crack-tip constraint conditions experienced in structures. Linear elastic fracture mechanics (LEFM) crack orientation is modelled with the finite element method in SENT model considering its geometry functions a/W ratio to determine its crack growth rate based on constant amplitude load. The virtual crack closure technique tool in MSC Marc/Mentat software with adaptive and global remeshing is applied to assess high cycle fatigue crack propagation using the SENT model. The crack growth pattern for the 3-dimensional simulation characteristics is similar with that of the CT Specimen experimental procedure. Furthermore, the results of the crack propagation and the cycle count demonstrated good agreement with bearable discrepancy with maximum percentage difference of about 14.1 % for the HAZ and 6.4% for the weld and parent metal compared to the experimental results from literature

    Gene discovery via expressed sequence tags from oil palm (Elaeis guineensis Jacq.) mesocarp.

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    Expressed sequence tags (ESTs) have been used for many applications such as to reveal gene expression patterns, gene regulation and sequence diversity. A total of 1011 unique transcripts corresponding to 1463 genes have been identified from the ESTs generated from 17-week oil palm mesocarp cDNA library. This approach was found to be successful in the discovery of new and important genes expressed in the mesocarp tissue which are associated with the various cellular processes of the tissue. It was observed that 12.9% of the total genes expressed in the 17-week mesocarp cDNA library can be categorized under metabolism. This is in agreement with the function of the tissue which is involved in many biochemical processes including amino acid and fatty acid metabolism. Most importantly are the discoveries of genes playing important roles in the fatty acid and wax biosynthesis pathway such as acetyl-CoA carboxylase, stearoyl-ACP desaturase, acyl carrier protein (ACP), lysophosphatidic acid acyltransferase, ?6-palmitoyl-ACP desaturase and lipase. These genes can serve as targets for genetic manipulation where such endeavours have been extensively carried out in other plants such as Brassica napus and Olea europaea to help increase the economic value of the oil. Genes and protein associated with ethylene synthesis and signal transduction pathway were also identified from the 17-week mesocarp ESTs. Dot blot analysis was carried out to help in identifying potential tissuespecific genes, which can lead to the isolation of the tissue-specific promoters for manipulation of the mesocarp tissue. This is in particular to direct accumulation of transgenic products, such as new specialty oils and value-added products like pharmaceuticals and nutraceuticals to the mesocarp

    Computational fluid dynamics study of pull and plug flow boundary condition on nasal airflow

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    The recent advances in the computer based computational fluid dynamics (CFD) software tools in the study of airflow behavior in the nasal cavity have opened an entirely new field of medical research. This numerical modeling method has provided both engineers and medical specialists with a clearer understanding of the physics associated with the flow in the complicated nasal domain. The outcome of any CFD investigation depends on the appropriateness of the boundary conditions applied. Most researchers have employed plug boundary condition as against the pull flow which closely resembles the physiological phenomenon associated with the breathing mechanism. A comparative study on the effect of using the plug and pull flow boundary conditions are evaluated and their effect on the nasal flow are studied. Discretization error estimation using Richardson's extrapolation (RE) method has also been carried out. The study is based on the numerical model obtained from computed tomographic data of a healthy Malaysian subject. A steady state Reynold averaged Navier–Stokes and continuity equations is solved for inspiratory flow having flow rate 20 L/min representing turbulent boundary conditions. Comparative study is made between the pull and plug flow model. Variation in flow patterns and flow features such as resistance, pressure and velocity are presented. At the nasal valve, the resistance for plug flow is 0.664 Pa-min/L and for pull flow the value is 0.304 Pa-min/L. The maximum velocity at the nasal valve is 3.28 m/s for plug flow and 3.57 m/s for pull flow model

    Review: A critical overview of limitations CFD Modeling in nasal airflow.

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    Computational fluid dynamics (CFD) modeling of nasal airflow has been carried out by several researchers. Virtual surgical treatment and aerosol deposition studies have also been conducted. However, the appropriateness of such modeling practices with regards to modeling and medical constraints needs careful consideration. The current numerical models for the study of nasal airflow, developed from the scanned images obtained from computed tomography or magnetic resonance imaging, are influenced by postural changes. These models neglect the mucous layer, other vital anatomical features, and nasal cycle effects, CFD studies make numerous assumptions that seriously limit their usefulness. Unless these constraints can be addressed, the interpretation of results from a CFD output cannot be considered as an appropriate definition of the flow behavior. This review provides a critical overview of the limit actions of the CFD mode ling of nasal air-low. Some of the limitations and constraints associated with CFD modeling are reviewed and possible studies that could be carried out in the future to ascertain the effect of neglecting these parameters are discussed. This study also proposes a standard station of the computational modeling procedure, which is necessary for studying airflow inside the nasal cavity

    Determination of optimum combination of voxel size and b-value for brain diffusion tensor imaging

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    Optimum combination of voxel size resolution and b-value for whole brain imaging has been determined. Data images were acquired using a 1.5T magnetic resonance imaging (MRI) system (GE Signa HDxt). Diffusion tensor imaging (DTI) scan was performed on phantom and a human volunteer. Six protocols which consist of various combination of voxel size and b-value were evaluated. Measurement of signal-to-noise ratio (SNR) and DTI parameter indices were carried out for both phantom and in-vivo studies. Due consideration was given to a combination of parameters yielding sufficient SNR with DTI values comparable to those obtained from previous reported studies. For the phantom study, SNR ≥ 20 was found in all of the protocols except for a combination of voxel size of 2.0 × 2.0 × 2.0 mm3 with b-value of 1200 s/mm2 (V2.0 B1200) and that of voxel size of 2.0 × 2.0 × 2.0 mm3 with b-value of 1000 s/mm2 (V2.0 B1000). For in-vivo study, all protocols presented SNR > 20. It was found that a combination of voxel size of 2.5 × 2.5 × 2.5 mm3 with b-value of 1000 s/mm2 (V2.5 B1000) and that of voxel size of 2.5 × 2.5 × 2.5 mm3 with b-value of 700 s/mm2 (V2.5 B700) displayed the most comparable ADC and FA values with references. In terms of anatomic coverage, V2.5 B700 was found better than V2.5 B1000 as it assures coverage of the whole brain. In conclusion, a combination of voxel size of 2.5 × 2.5 × 2.5 mm3 with b-value of 700 s/mm2 was considered as optimum parameters for brain DTI

    Diagnostic Cerebral Angiography in Spontaneous Intracranial Haemorrhage: A Guide for Developing Countries

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    ObjectiveSpontaneous intracranial haemorrhage constitutes 18-40% of all stroke cases. Indications for cerebral angiography to find underlying potentially treatable vascular abnormalities are not clear. This study determined which intracranial haemorrhage patients need cerebral angiography by correlating computed tomography (CT) findings, age and hypertension history with cerebral angiography findings.MethodsA total of 54 patients (8-79 years) with intracranial haemorrhage who underwent both CT examination and six-vessel cerebral angiography were studied over a 2-year period. Cerebral angiography was repeated within 6 weeks if the first angiogram was negative.ResultsAngiography detected vascular lesions in 50% of cases (aneurysm 38.9% and arteriovenous malformation, AVM, 11.1%). In the aneurysm group, angiographic yield was 34.3% whereas in the AVM group, it was 37.9%. Subarachnoid haemorrhage (SAH) combined with other types of haemorrhage (such as intracerebral haemorrhage, ICH) was not significantly correlated with the likelihood of finding a vascular lesion, both aneurysm and AVM (p = 0.157). Age less than 50 years had significant correlation (p = 0.021) in the AVM group as well as in the aneurysm group (p < 0.001). A history of hypertension was associated with both aneurysm (p = 0.039) and AVM (p = 0.008). No patients with deep intracerebral haematoma had vascular lesions. The presence of an intraventricular haemorrhage (IVH) had significant correlation with aneurysm (p = 0.008) but not AVM. There was no significant difference in mean age between patients with and without a vascular lesion (p = 0.134).ConclusionCerebral angiography is justified in patients with pure SAH (p = 0.001). Other factors associated with finding a vascular lesion were a history of hypertension and the presence of IVH. Diagnostic cerebral angiography is indicated for patients with ICH and SAH and IVH with a history of hypertension, regardless of age

    Aesthetic Appreciation of Kelantan Heritage Ceramics: An Indicator for Sustainability

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    Apart from creating clay objects with unlimited variety of shapes, the surface can also be decorated with patterns in many ways to enhance the overall appearance. As a result of this, surface decorations have been one of the major heritage values in ceramic studies. Thus, applying Gestalt theory and Golden section rule, this paper seeks to identify the unique heritage values in Kelantan ceramics that can be sustained as genius loci. Pictorial data (decorative patterns) were collected by visiting six museums in Kelantan and the data were analyzed with the aid of PhiMatrix software. The result shows eleven (11) decorative patterns that conform to the golden section rule and the Gestalt principles of grouping elements. Hence, sustaining this heritage values will not only serve as identity, but also demonstrate the recognition of the beauty of the past. Keywords: Aesthetic, Heritage ceramics, Surface decoration, Decorative motifs, Kelantan

    Analysis of pediatric subdural empyema outcome in relation to computerized tomography brain scan

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    A cross-sectional study was conducted to predict the outcome in patients with subdural empyema, using initial and post-treatment CT scan brain parameters. Data collection was done on those children who were diagnosed to have subdural empyema by CT scan of the brain with contrast, who underwent burrhole evacuation, from February 2000 until April 2002. Numerous factors, such as coma or loss of unconsciousness at diagnosis, age, types of antibiotic, microbiology, extension of empyema, associated cerebral infarction and ventriculitis, were analyzed. Poor prognosis was associated with loss of consciousness, and hypodensity by CT scan at presentation (p < 0.005). Patients with an extensive subdural empyema will have a good outcome if they are treated early and aggressively with antibiotics and burrhole evacuation
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