669 research outputs found

    The usefulness of pleural fluid alkaline phosphatase and its ratio to serum alkaline phosphatase levels in classifying pleural effusions as exudates and transudates and its correlation with light’s criteria

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    INTRODUCTION: Pleural effusion is a very common clinical presentation of diseases. A correct diagnosis of the underlying disease is essential for the management of pleural effusion. A limited number of diseases cause Transudative Pleural Effusion, whereas exudative effusions require more extensive diagnostic investigations. Therefore, the first step is to classify them as transudates or exudates, even if this differentiation does not contribute to the etiological diagnosis. Many criteria have been used to distinguish them, but none of them have been found to be satisfactory. Light’s criteria is the most commonly used method. The criteria is one or more of the following to diagnose exudates. 1. Pleural fluid protein / Serum protein > 0.5 2. Pleural fluid LDH/ Serum LDH > 0.6. 3. Pleural fluid LDH more than 2/3rd of the upper limit of serum. AIMS AND OBJECTIVES: To evaluate the advantages of Total Pleural fluid Alkaline Phosphatase (ALP) and its ratio to Serum Alkaline Phosphatase levels in classifying Pleural Effusions as Exudates or Transudates. MAREIALS & METHOD: This study is to be conducted among 60 patients with pleural Effusion, attending the Department of Medicine & Department of Thoracic Medicine in Govt. Rajaji Hospital, Madurai. METHODOLOGY: This study was conducted in Govt. Rajaji Hospital, Madurai which is affiliated to Madurai Medical College. This study subjects were selected from the patients admitted in Department of Medicine and Department of Medicine, Govt. Rajaji Hospital. The study was conducted in 60 patients; the patients had pleural effusion with clinical background of congestive cardiac failure, chronic liver disease, chronic kidney disease, tuberculosis, parapneumonic effusions, malignancy. RESULT: “By applying Light’s criteria in patients with exudative pleural effusion classified clinically, 81.8% of the cases were correctly diagnosed as exudative pleural effusion. By applying Pleural fluid Alkaline phosphatase in patients with exudative pleural effusion classified clinically, 87.8% of the cases were correctly diagnosed as exudative pleural effusion. Among the parameters used most specific test to classify an exudative pleural effusion from a transudative pleural effusion is pleural fluid total protein which is 95.45% and most sensitive test is pleural fluid / serum alkaline phosphatase ratio which is 93.90%. The positive predictive value, negative predictive value and diagnostic accuracy to classify an exudative pleural effusion from a transudative pleural effusion is higher for pleural fluid total protein which is 96.29%, 95.23%, 94% respectively. CONCLUSION: For many decades Light’s criteria had been used widely to differentiate exudative from transudative pleural effusion. But it also misclassified 25% of transudates as exudates, so there was a need to identify new parameters which would prove to be superior or supportive to the array of tests at present

    Potassium status of some coconut growing soils of Sri Lanka

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    Group Key Rekeying Technique with Secure Data Encryption in MANETs

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    A Mobile Ad hoc Network (MANET) is a collection of autonomous nodes or mobile devices that can arrange themselves in various ways and operate without strict network administration. Ensuring security in mobile ad hoc network is a challenging issue and most of the applications in mobile ad hoc networks involve group-oriented communication. In Mobile ad-hoc network, each node treated as a terminal and also acts as an intermediate router. In this scenario, multi-hop occurs for communication in mobile ad hoc network. There may be a possibility of threats and malicious nodes in between source and destination. Providing the security in MANET is entirely different from the traditional wired network. In the present scenario, various applications of the mobile ad hoc network have been proposed and issues are solved by using the cryptographic techniques. Mostly cryptographic techniques are used to provide the security to MANETs. Cryptographic techniques will not be efficient security mechanism if the key management is weak. The purpose of key management is to provide secure procedures for handling keys in the cryptographic technique. The responsibilities of key management include key generation, key distribution, and key maintenance. Several key management schemes have been introduced for MANETs. The Group key management scheme is an efficient method for key management in MANET. In group key management scheme, rekeying is used whenever a new node joins or existing node leaves from the group. In this paper, we propose a periodic rekeying method (PRK) and analyze the performance of LKH rekeying techniques in a group key management schemes. The symmetric encryption techniques are analyzed with different parameters, such as Throughput and Energy consumption. Security and performance of rekeying protocols are analyzed through detailed study and simulation

    Toxicity characterization and long-term stability studies on copper slag from the ISASMELT process

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    Detailed studies on the toxicity and long-term stability of copper slag of varying heavy metal concentration generated over a 14-week period in an Indian copper plant through the ISASMELT process was carried out using USEPA's toxicity characteristic leaching procedure (TCLP), multiple extraction procedure and sulfuric acid leaching of granulated and mechanically activated slag as a function of pH at two different temperatures. The TCLP, acid leaching and multiple extraction test results carried out on a large number of slag samples of varying compositions derived from the use of several copper concentrates indicate poor leachability of the heavy metals and assures long-term stability even in extreme atmospheres. Leaching tests on mechanically activated samples gives an idea of the resistance to leaching of the heavy metals even upon weathering. The multiple extraction leaching tests indicate that the heavy metals present in the slag are stable and are not likely to dissolve significantly even through repetitive leaching under acid rain in a natural environment. The highest concentration of all the elements is far below the prescribed limits in USEPA 40CFR Part 261

    Use of nanofiltration and reverse osmosis in reclaiming micro-filtered biologically treated sewage effluent for irrigation

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    Micro-filtered, biologically treated sewage effluent (BTSE) generally has high sodium adsorption ratio (SAR) and sodium (Na) and chloride (Cl) concentrations. Therefore it cannot be directly used for irrigating sensitive crops. A study was conducted on a micro-filtered BTSE from a Sydney water treatment plant to determine whether the BTSE can be treated using nanofiltration (NF) and reverse osmosis (RO) to bring these risk parameters within safety limits. The study showed that using NF and RO alone could not produce the required ratio of SAR. Furthermore, NF alone did not remove the necessary levels of Na and Cl ions while RO did. However, blending equal proportions of NF permeate and RO permeate obtained from a two stages hybrid treatment system consisting of NF followed by RO resulted in a product quality suitable for irrigation in terms of the above mentioned risk factors. Utilizing NF prior to RO reduced the RO membrane fouling as well. Both NF and RO removed most of the pharmaceutical and personal care products from the feed water and this may subsequently protect soil and ground water from potential hazards

    GPRKEY - A NOVEL GROUP KEY REKEYING TECHNIQUE FOR MANET

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    A Mobile Ad hoc Network (MANET) is a collection of autonomous nodes or mobile devices that can arrange themselves in various ways and work without strict network administration. Ensuring security in mobile ad hoc networks is a challenging issue and most of the applications in mobile ad hoc networks involve group oriented communication. Mostly cryptographic techniques are used to provide the security to MANETs. Cryptographic techniques will not be efficient security mechanism if the key management is weak. The issue of packet loss in MANET that is caused due to multi casting and backward and forward secrecy results in mobility. Hence, we investigate on this issue and propose a method to overcome this scenario. On analysing the situation we find that frequent rekeying leads to huge message overhead and hence increases energy utilization. With the existing key management techniques it causes frequent disconnections and mobility issues. Therefore, an efficient multi casting group key management will help to overcome the above problems. In this paper we propose a novel group key rekeying technique named GPRKEY (Group key with Periodic ReKEYing) deal with scalability issue of rekeying and also analyze the performance of the newly proposed key management method using key trees. In this approach we use the periodic rekeying to enhance the scalability and avoid out of sync problems. We use sub trees and combine them using the merging algorithm and periodic re-keying algorithm. The GPRKEY is evaluated through NS-2 simulation and compared with existing key management techniques OFT (One-way Function Tree) and LKH (Logical Key Hierarchy). The security and performance of rekeying protocols are analyzed through detailed study and simulation

    Submerged membrane filtration adsorption hybrid system for the removal of organic micropollutants from a water reclamation plant reverse osmosis concentrate

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    © 2016 Elsevier B.V. Reverse osmosis (RO) is a widespread water treatment process utilised in water reuse applications. However, the improper discharge of RO concentrate (ROC) containing organic micropollutants such as pharmaceuticals into the environment may cause potential health risks to non-target species and particularly those in aquatic environments. A study was conducted using a submerged membrane-filtration/granular activated carbon (GAC) adsorption hybrid system to remove organic micropollutants from a water treatment plant ROC by initially adding 10 g GAC /L of membrane reactor volume with 10% daily GAC replacement. The percentage of dissolved organic carbon removal varied from 60% to 80% over an operation lasting 10 days. Removal of organic micropollutants was almost complete for virtually all compounds. Of the 19 micropollutants tested, only two remained (the less hydrophobic DEET 27 ng/L and the hydrophilic sulfamethoxazole 35 ng/L) below 80% removal on day 1, while five of the most hydrophobic micropollutants were detectable in very small concentrations ( 89%–> 99% being removed. High percentages of micropollutants were removed probably because of their high hydrophobicity or they had positive or neutral charges and therefore they were electrostatically adsorbed to the negatively charged GAC

    Numerical studies of steel channels with staggered slotted perforations subject to combined bending and shear actions

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    Cold-formed steel studs and purlins with staggered slotted perforations in webs are used in construction to improve thermal performance of the profiles and energy efficiency of structures. On the other hand, the web perforations adversely affect structural performance of the members, especially their shear, bending and combined bending and shear strengths. Relatively little research has been reported on this subject despite its importance. Many research studies have been carried out to evaluate the combined bending and shear behaviour of conventional cold-formed channel beams. To date, however, no investigation has been conducted into the strength of cold-formed steel channels with staggered slotted perforations under combined bending and shear actions. Finite element models of cold-formed steel channels with staggered slotted perforations were developed to simulate their combined bending and shear behaviour and strength. They were then validated by comparing the results with available experimental test results and used in a detailed parametric study. This paper presents the details of the numerical studies of cold-formed steel channels with staggered slotted perforations and the results

    Barriers to the Effective Adhesion of High-Density Hardwood Timbers for Glue-Laminated Beams in Australia

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    A number of international timbers of high commercial importance are extremely difficult to glue, which is significantly hindering access to global market opportunities for engineered wood products, especially for heavily demanded structural products. Some particularly problematic timbers in Australia are the dominant commercial hardwood species, including spotted gum (Corymbia spp.) and Darwin stringybark (Eucalyptus tetrodonta). These species are renowned for their very high mechanical properties, natural durability and attractive aesthetic appeal. However, they are notoriously difficult to glue, especially for sawn laminate-based engineered wood products, such as structural glue-laminated beams. Despite considerable effort and testing of diverse internationally established best-practice approaches to improve adhesion, glue-laminated beam samples of these timbers still frequently fail to meet the requirements of the relevant standard, mainly due to excessive glue line delamination. This paper discusses the key barriers to effective adhesion of these high-density timbers and particularly emphasises the necessity of achieving greater adhesive penetration. Greater adhesive penetration is required to enhance mechanical interlocking, entanglement and molecular interactions between the adhesive and the wood to achieve stronger and more durable bonds. Potential solutions to enhance adhesive penetration, as well as to improve gluability in general, are discussed in terms of their likelihood to satisfactorily prevent delamination and the potential to be applied at an industrial scale. This new fundamental understanding will assist the development of solutions, allowing industry to commercialise newly engineered wood products made from high-density timbers
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