313 research outputs found
Evaluation of Cardiovascular Changes in Chronic Obstructive Pulmonary Disease and Its correlation with the disease severity
INTRODUCTION :
Chronic Obstructive Pulmonary Disease (COPD) has
considerable effects on cardiac function, including those of the right
ventricle, left ventricle and pulmonary blood vessels.
Chronic Obstructive Pulmonary Disease (COPD), a common
preventable and treatable disease is characterised by persistent air flow
limitation that is usually progressive and associated with an enhanced
chronic inflammatory response in the airways and lungs to noxious
particles or gases. Exacerbations and comorbidities contribute to the
overall severity in the individual patients.
COPD is one of the leading causes of morbidity and mortality
worldwide and results in an economic and social burden. The global
burden of disease study projected that COPD, which ranked sixth as a
cause of death in 1990 will become the third leading cause of death
worldwide by 2020. Many patients with COPD have comorbidities
that have a major impact on quality of life and survival.
Airflow limitation and particularly hyperinflation affect cardiac
function and gas exchange. Pulmonary hypertension may develop late
in the course of COPD and is mainly due to hypoxic vasoconstriction
of small pulmonary arteries, eventually resulting in structural changes
that include intimal hyperplasia and later smooth muscle
hypertrophy/hyperplasia. The loss of pulmonary capillary bed in
emphysema may also contribute to increased pressure in the
pulmonary circulation. Progressive pulmonary hypertension may lead
to right ventricular hypertrophy and eventually to right sided cardiac
failure.
Progressive impairment of left ventricular diastolic function
correlates with the severity of pulmonary Hypertension. It is likely
that this results in large part from bulging of the inter ventricular
septum from the hypertrophied and dilated right ventricle into the
cavity of the left ventricle.
Most of the increased mortality associated with COPD is due to
the cardiac involvement. Echocardiography provides a rapid, noninvasive,
portable and accurate method to evaluate the cardiac
changes. In South India, studies are not found easily related to
cardiovascular abnormalities in mild to very severe COPD. This study
is to find out the specific effects on the right ventricle, left ventricle
and pulmonary blood vessels due to COPD and their relation to its
severity.
AIM :
1. To assess the cardiovascular changes secondary to COPD by
echocardiography.
2. To find out the correlation between the cardiovascular changes
and the severity of COPD.
MATERIALS AND METHODS
STUDY CENTRE
Institute of Thoracic Medicine, Chetpet and Department of
Thoracic Medicine, Rajiv Gandhi Government General Hospital,
Chennai, and Department of Cardiology, Rajiv Gandhi Government General
Hospital, Chennai.
STUDY DESIGN : Observational study.
STUDY PERIOD : From February 2012 to November 2012.
INCLUSION CRITERIA :
1. known case of COPD patients,
2. newly diagnosed COPD patients,
3. age group >30 years.
EXCLUSION CRITERIA :
1. PT Sequelae,
2. known diabetics,
3. known Hypertensives,
4. h/o ischaemic cardiac disease and valvular heart
Disease,
5. known case of Bronchial asthma and Interstitial lung
disease.
METHODOLOGY :
About 51 COPD patients with unknown severity who have
attended as out-patients in Institute of thoracic medicine, Chetpet
and Department of thoracic medicine, Rajiv Gandhi Government
general hospital, Chennai were subjected to following
investigations. The study was done within a time period of ten months.
Written consent was obtained from the patients in their regional language, after explaining the details of the study. Complete history regarding the symptoms, past history, smoking history, occupational history and other associated illnesses were taken and noted in a proforma. Clinical examination of the patients had been done.
CONCLUSION :
1. There is increase in right ventricular global dysfunction and also pulmonary hypertension in COPD patients as the severity increases.
2. All COPD patients should undergo cardiac evaluation using
echocardiogram to detect early cardiac abnormalities so as to prevent cardiac mortality and morbidity
Robust recognition technique for handwritten Kannada character recognition using capsule networks
Automated reading of handwritten Kannada documents is highly challenging due to the presence of vowels, consonants and its modifiers. The variable nature of handwriting styles aggravates the complexity of machine based reading of handwritten vowels and consonants. In this paper, our investigation is inclined towards design of a deep convolution network with capsule and routing layers to efficiently recognize Kannada handwritten characters. Capsule network architecture is built of an input layer, two convolution layers, primary capsule, routing capsule layers followed by tri-level dense convolution layer and an output layer. For experimentation, datasets are collected from more than 100 users for creation of training data samples of about 7769 comprising of 49 classes. Test samples of all the 49 classes are again collected separately from 3 to 5 users creating a total of 245 samples for novel patterns. It is inferred from performance evaluation; a loss of 0.66% is obtained in the classification process and for 43 classes precision of 100% is achieved with an accuracy of 99%. An average accuracy of 95% is achieved for all remaining 6 classes with an average precision of 89%
Canine Parvovirus Isolates of India and the Relevance of Canine Parvovirus Type-2 Vaccines
A study was conducted to characterise the field isolates of canine parvovirus (CPV) and an in vitro cross neutralisation assay was performed against the vaccinated dog sera. Out of 45 faecal samples processed for virus isolation, 27 samples showed cytopathic effect (CPE) at first passage, which were confirmed positive by CPV variant types specific PCR. The CPV type 2 was not detected in any of the clinical samples. Of these 27 positive samples only 23 samples showed CPE and were further confirmed as CPV by haemagglutination inhibition test, ELISA and immuno-chromatographic strip test. Antigenic typing performed using a panel of monoclonal antibodies revealed that four of the 23 isolates were CPV 2b type and the remaining 19 isolates were typed as CPV 2a. The antigenic typing results obtained using the monoclonal antibodies corroborated the sequencing results reported by our group earlier. The cross neutralization study with polyclonal sera revealed that the sera of original antigenic type CPV 2 can neutralize the antigenic variants 2a and 2b effectively. Thus we conclude that the vaccines containing CPV type 2 virus can be used to immunise the dogs against the prevalent CPV 2a and CPV 2b infection. A live virus challenge study in dogs may further confirm this observation
Mechanism of haematotoxicity induced by phenylhydrazine: a review
This work was carried out to show the effects of phenylhydrazine (PHZ) induced anaemic condition. Anaemic condition is defined as reduction in red blood cells (RBC) than normal number of red blood cells. The anti-anaemic activity can be studied using the changes in haematological parameters (PCV, RBC & Haemoglobin) influenced by PHZ [(40mg/kg p.o.)] in rats. PHZ, a potent chemical that causes different effects on different tissues at several levels. Administration of PHZ causes haemolytic anaemia, genotoxic effects and rose in iron absorption in spleen, liver and duodenum & causes change in iron metabolism. PHZ acts by activating immune response which triggers phagocytosis and also interfere with the binding of erythropoietin (EPO) receptors and further JAK-STAT pathway. PHZ also causes genotoxic effect by forming single strand DNA damage. In view of lipid peroxidation along with the formation of Thiobarbituric acid (TBA)-reactive malonyldialdehyde, it is recommend that PHZ induces anaemia as an outcome of peroxidation of RBC membrane lipids and this effect may be a upshot of the autoxidation of the drug and the interaction of membrane lipids and oxygen radical
COMPARATIVE ANALYSIS OF 4-BIT AND 8-BIT REVERSIBLE BARREL SHIFTER DESIGNS USING REVKIT
ABSTRACT In the recent years, reversible logic has emerged as a viable approach in power optimization and also has found its importance in low power CMOS, quantum computing, nanotechnology, and optical computing. The main challenge in reversible circuits is to optimize the quantum cost, time delay and the garbage outputs associated with the reversible circuit. 'RevKit' in recent years has become a popular and powerful tool for design visualization, implementation and analysis in reversible computing. In this work, we have implemented the design of reversible 4-bit and 8-bit barrel shifter circuits in RevKit and results are analyzed in terms of quantum cost, delay, garbage outputs, gate count, line count and transistor cost. Further, the simulation results have been documented and tabulated to facilitate a comparative study with conventional designs. Keywords: reversible circuits, barrel shifters, quantum cost, time delay, garbage output, RevKit. INTRODUCTION In irreversible logic computations [1], each bit of information lost generates kTln2 joules of heat energy, where k is Boltzmann's constant and T is the absolute temperature at which the computation is performed. Thus, the amount of energy dissipated in a system bears a direct relationship to the number of bits erased during the computation. The kTln2 energy dissipation can be avoided [2] if a computation is carried out in a reversible manner Rotating and shifting data in a single cycle are required in several applications like efficient computations and arithmetic operations. Barrel shifters, more suitable for this kind of operations, since, it is capable of shifting or rotating the inputs in a single cycle and find great importance in the digital signal processing computation. In reversible system information is not erased. The number of inputs and outputs are equal in reversible gates, which means that the input stage can always be retained from the output stage. Thus, such an implementation of reversible barrel shifter will be highly efficient when compared to any conventional design in terms of time delay, garbage output or the quantum cost associated with such a structure. The majority of the work that currently exists in literature focuses on optimizing the reversible sequential designs in terms of number of reversible gates and garbage outputs using functional verification. A few prior works have used design tools such as RevKi
Glass Fracture Upon Ballistic Impact: New Insights From Peridynamics Simulations
Most glasses are often exposed to impact loading during their service life, which may lead to the failure of the structure. While in situ experimental studies on impact-induced damage are challenging due to the short timescales involved, continuum-based computational studies are complicated by the discontinuity in the displacement field arising from the propagation of cracks. Here, using peridynamics simulations, we investigate the role of the mechanical properties and geometry in determining the overall damage on a glass plate subjected to ballistic impact. In particular, we analyze the role of bullet velocity, bullet material, and elastic modulus, fracture energy, and radius of the plate. Interestingly, we observe a power-law dependence between the total damage and the fracture energy of the glass plate. Through an auto-regressive analysis of the evolution of cracks, we demonstrate that the self-affine growth of cracks leads to this power-law dependence. Overall, the present study illustrates how peridynamic simulations can offer new insights into the fracture mechanics of glasses subjected to ballistic impacts. This improved understanding can pave way to the design and development of glasses with improved impact-resistance for applications ranging from windshields and smart-phone screens to ballistics
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