A NOVEL MATLAB MODEL OF ANN BASED CONTROLLERS TO IMPROVE THE DYNAMIC PERFORMANCE OF A SHUNT ACTIVE POWER FILTER

This paper attempts to enhance the dynamic performance of a shunt-type active power filter. The predictive and adaptive properties of artificial neural networks (ANNs) are used for fast estimation of the compensating current. The dynamics of the dc-link voltage is utilized in a predictive controller to generate the first estimate followed by convergence of the algorithm by an adaptive ANN (adaline) based network. Weights in adaline are tuned to minimize the total harmonic distortion of the source current. Extensive simulations and experimentations confirm the validity of the proposed scheme for all kinds of load (balanced and unbalanced) for a three-phase three-wire system

Traditional method or online teaching; which method students prefer: an observational study

Background: An unexpected global pandemic broke out in initial months of 2020 i.e., COVID-19 which drastically brought a difference in the progress of education in various institutions, especially the medical field where we study about life was also made online. This study aims to conduct a comparative analysis of students ‘opinion regarding which is the better, traditional teaching or online live teaching.Methods: Survey was conducted among two group of students, 2019 (both online and offline teaching) and 2020 (online teaching with offline practical) batches of Andhra Medical College, Visakhapatnam. A questionnaire was circulated to students regarding the class experience, interest of attending the class, learning effect and clarity of the lecture. Results: Students expressed their views that overall teaching experience and learning effect of offline methodology is superior to online approach, so the traditional offline style or the blend of online and offline modes are apt for teaching.Conclusions: The study is focused on the way in which the teaching and learning approach is delivered which is favoured by the medical practitioners, the qualitative data suggesting required modifications for further improvement in the delivering method to produce qualified medical practitioners to meet the current and imminent situations. This study suggests that a intermingled learning approach is an effective method for anatomy learning, and this approach mainly inculcates self-directed study through online learning

A morphomertic study of dry human typical thoracic vertebral body in coastal region, Andhra Pradesh

Background: The frequent surgical interventions of the thoracic spine are more common due to a wide array of traumatic, degenerative, and neoplastic diseases. For successful surgical management of these conditions, detailed anatomical knowledge of the thoracic vertebrae is required. Previous studies in the past about morphometry of thoracic vertebrae mainly focused on pedicle diameters and their angulations. The vertebral body was not studied particularly in the coastal region, Andhra Pradesh which is the reason the present study has given importance to the morphometry of the vertebral body. Aim was to measure the various parameters of the vertebral body in typical thoracic vertebrae.Methods: 82 dry human typical thoracic vertebrae from the department of anatomy, Andhra Medical College, Visakhapatnam were studied for the various morphometric parameters.Results: The antero posterior distance of the vertebral body in typical thoracic vertebrae ranged from 14.5-27.5 mm with a mean of 21.77 mm. The vertebral body superior transverse diameter ranged from 18.1-38.7 mm with a mean of 28.22 mm. The vertebral body inferior transverse diameter ranged from 22.6-41.2 mm with a mean of 31.3 mm. The anterior height of the body ranged from 10.2-24.1 mm with a mean of 18.17 mm. The right and left lateral height of the body ranged from 9.0-24.7 mm with a mean of 18.4 mm.Conclusions: The results provide information for more accurate modelling and design of vertebral body implants and instrumentations for the Indian population

Management of gastrointestinal stromal tumours in the Imatinib era: a surgeon's perspective

<p>Abstract</p> <p>Background</p> <p>Surgical resection has remained the mainstay of treatment of GIST with a 5-year-survival of 28–35%. Tyrosine kinase inhibitor (Imatinib) has revolutionised the treatment of these tumours. The current research is directed towards expanding the role of this drug in the treatment of GIST. We present our experience of managing GIST in this institute.</p> <p>Methods</p> <p>This is a case note study of patients identified from a prospectively kept database from January 2000 to August 2007.</p> <p>Results</p> <p>16 patients were diagnosed with GIST. The median age was 66 years (range 46 to 82) and the male to female ratio was 9:7. Eleven patients underwent surgery, 9 of which had R0 resection (2 laparoscopic, 1 converted to open), one had an open biopsy and one had a debulking procedure. 3 patients were inoperable and 2 were found to be unfit for surgery. Five patients received Imatinib (2 postoperatively). The risk assessment based on morphological criteria showed that 4 patients had low, 4 had intermediate and 8 had high malignant potential. The median follow up was for 12 months (range 3–72); 2 patients died of unrelated causes at 6 and 9 months after diagnosis.</p> <p>Conclusion</p> <p>Most GISTs can be managed effectively using existing protocols. However currently there is no evidence based guidance available on the management of GIST in the following situations-role of debulking surgery, the follow up of benign tumours not requiring surgical resection and role of laparoscopic surgery. Further research is needed to answer these questions.</p

Galbladder perforation: The importance of standardised treatment algorithms

Von H. Barfo

Development of successive cambia and structure of the secondary xylem in some members of the family Amaranthaceae

Young stems of Aerva javanica (Burm.f.) Juss. ex Schult., A. lanata (L.) Juss. ex Schult, A. monsonia Mart., A. sanguinolenta (L.) Blume, Alternanthera bettzickiana (Regel) G. Nicholson, A. philoxeroides (Mart.) Griseb., Gomphrena celosioides Mart., G. globosa L. and Telanthera ficoidea (L.) Moq., showed the renewal of small sectors of cambium by replacing with new segments. Therefore, the secondary phloem formed by earlier cambial segments form isolated islands of phloem enclosed within conjunctive tissues became embedded in the secondary xylem. As the stem grows older, complete ring of cambium is renewed; sometimes an anastomosing network of successive cambia may be seen due to the renewal of larger segments of the cambium. Renewal of the cambium takes place by repeated periclinal division in the parenchyma cells positioned outside to the phloem formed by the previous cambium. Functionally the cambium is bidirectional and exclusively composed of fusiform cambial cells. Differentiation of conducting elements of the secondary xylem and phloem remains restricted to the certain cambial cells while rest of the segments exclusively produce conjunctive cells. Accumulation of starch along with the presence of nuclei in the xylem fibers even after deposition of the secondary wall is consistent in all the species and it seems to be associated with the absence of rays in the secondary xylem and phloem of nine species from four genera. The significance of successive cambia, rayless xylem and nucleated xylem fibers were correlated with plant habit

Formation of medullary phloem in Argyreia nervosa (Burm. f.) Bojer

Histologically, family Convolvulaceae is characterised by the presence of successive cambia, medullary (internal/intraxylary) and interxylary phloem in majority of the species, whereas some of the members are devoid of successive cambia and medullary bundles. The present study on Argyreia nervosa (Burm. f.) Bojer showed the presence of medullary bundles while internal phloem was absent during the primary growth. As the secondary growth progressed, successive cambia initiated from the pericyclic parenchyma. Development of medullary bundles began along with the regular protoxylem and protophloem while formation of intraxylary phloem was observed only after the initiation of secondary growth. Medullary/intraxylary sieve elements began to develop from the marginal pith cells. In thick stems, small segments of internal cambium initiated between the protoxylem and internal phloem. This internal cambium was functionally unidirectional and produced internal phloem centripetally. Developmental particulars are described in details along with its significance

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries