25 research outputs found
Development of the Flight Dynamic Model (FDM) Using Computational Fluid Dynamic (CFD) Simulations for an Unknown Aircraft
The usage of computational fluid dynamics (CFD) has enhanced 10-fold since the last decade, especially in the area of aerospace science. In this chapter, we will focus on determining the feasibility and validity of CFD results that are plugged in flight dynamic model (FDM) to that of actual flight of an aircraft. Flight data of an actual aircraft is used to determine the aerodynamic performance of the designed FDM. In addition to this, FDM consist of various systems integration of an aircraft; however, this study will focus on aerodynamic parameter optimization. Relative analysis is carried out to validate the FDM. This will enable readers to know how CFD can be a great tool for designing FDM of an unknown aircraft
The Impact of Transcatheter Atrial Septal Defect Closure in the Older Population A Prospective Study
ObjectivesWe sought to prove that device closure of atrial septal defect (ASD) in older patients not only improves cardiac function but also results in symptomatic relief by improving functional class.BackgroundAtrial septal defect accounts for approximately 10% of all congenital cardiac defects. It is possible that ASD closure in older patients may derive benefits, though this is not well established. We therefore aim to prospectively assess the clinical status and functional class of older patients after transcatheter ASD closure.MethodsThis was a prospective study of all patients age 40 years or more who underwent device closure of a secundum ASD between April 2004 and August 2006. Investigations including atrial and brain natriuretic peptide levels, electrocardiography, chest X-ray, transthoracic echocardiogram, 6-min walk test, and quality of life questionnaire were performed before and at 6 weeks and 1 year after the procedure.ResultsTwenty-three patients (median age 70 years, 13 women) had transcatheter device closure of ASD. Median ASD size was 18 mm (range 9 to 30 mm). Median pulmonary artery pressure was 22 mm Hg (range 12 to 27 mm Hg). At 1 year, New York Heart Association functional class improved (p = 0.004) in 16 patients with significant improvement in 6-min walk-test distance (p = 0.004) and physical (p = 0.002) as well as mental health score (p = 0.03). There were no major complications. One year following closure there was a significant change in left ventricular end-diastolic (p = 0.001) and end-systolic dimensions (p = 0.001) and also significant reduction in right ventricular end-diastolic dimension (p < 0.001).ConclusionsOur data demonstrated that ASD closure at advanced age results in favorable cardiac remodeling and improvement of functional class
Clinical and echocardiographic characteristics of patients with significant pericardial effusion requiring pericardiocentesis
Objective: Clinical and echocardiographic features of significant pericardial effusion (PE) have been reported from the west. Currently there is lack of published data from this part of the world, we reviewed all consecutive cases of significant PE requiring echocardiographic assisted pericardiocentesis to analyze the clinical and echocardiographic features of these patients.Methods: Forty four consecutive patients who underwent echocardiography assisted pericardiocentesis at the Aga Khan University Hospital (AKUH) between January 1988 and May 2001 re included in this review.Results: Most common presenting symptoms were dyspnea (89%) and fever (36%). Elevated JVP and pulsus paradoxus were documented in 59% and 41% of patients respectively. Sinus tachycardia (75%) and low voltage (34%) were the most common ECG findings. Malignancy (45-51%) and tuberculosis (27%) were among the most frequent causes of PE. One patient died during echocardiography-assisted pericardiocentesis.CONCLUSION: The symptoms and physical findings of haemodynamically significant PE are frequently nonspecific. Transthoracic echocardiography is the gold standard for rapid and confirmatory diagnosis of PE and cardiac tamponade. The most common cause of PE was malignancy followed by tuberculosis. Pericardiocentesis under echocardiographic guidance is a safe and effective treatment for significant PE
A review on the contamination of SARS-CoV-2 in water bodies: transmission route, virus recovery and recent biosensor detection techniques
The discovery of SARS-CoV-2 virus in the water bodies has been reported, and the risk of virus transmission to human via the water route due to poor wastewater management cannot be disregarded. The main source of the virus in water bodies is the sewage network systems which connects to the surface water. Wastewater-based epidemiology has been applied as an early surveillance tool to sense SARS-CoV-2 virus in the sewage network. This review discussed possible transmission routes of the SARS-CoV-2 virus and the challenges of the existing method in detecting the virus in wastewater. One significant challenge for the detection of the virus is that the high virus loading is diluted by the sheer volume of the wastewater. Hence, virus preconcentration from water samples prior to the application of virus assay is essential to accurately detect traceable virus loading. The
preparation time, materials and conditions, virus type, recovery percentage, and various virus recovery tech�niques are comprehensively discussed in this review. The practicability of molecular methods such as Polymer�Chain-Reaction (PCR) for the detection of SARS-CoV-2 in wastewater will be revealed. The conventional virus detection techniques have several shortcomings and the potential of biosensors as an alternative is also considered. Biosensing techniques have also been proposed as an alternative to PCR and have reported detection limits of 10pg/μl. This review serves to guide the reader on the future designs and development of highly sensitive, robust and, cost effective SARS-CoV-2 lab-on-a-chip biosensors for use in complex wastewater
Comparative evaluation of PCR success with universal primers of maturase K (matK) and ribulose-1, 5-bisphosphate carboxylase oxygenase large subunit (rbcL) for barcoding of some arid plants
Abstract DNA barcoding is the use of short DNA sequences (~650 bp) of the standard segment of the genome for large scale species identification. The Consortium for the Barcode of Life (CBOL) plant-working group recommended the 2-locus combination of rbcL and matK as the standard plant barcode. These two regions of chloroplast DNA were chosen due to efficient recovery of quality sequences and high levels of species discrimination. We evaluated the success rates of universal primers for amplification of matK and rbcL loci in 26 different plant species (covering 14 families) from Saudi Arabia. Success rate in PCR was higher for rbcL (88%) compared with matK (69%). The universal primers of both matK and rbcL failed to amplify the DNA form 3 plant species belonging to the family Asteraceae (Anthemis deserti, Pulicaria undulate, and Sonchus oleraceus). Two plant species Malva parviflora (Malvaceae) and Salsola imbricate (Chenopodiaceae) indicated different primer binding site (matK) as the amplified PCR products were of lower size than expected for these species. These findings indicate that although currently used universal primers of rbcL and matK are able to amplify many of the plant species they may fail in certain cases due to primer mismatch at the annealing site. Further studies are therefore needed for protocol development, particularly designing of novel universal primers, to extend the barcoding for a broader coverage of plant species
A Simple Method for DNA Extraction from Mature Date Palm Leaves: Impact of Sand Grinding and Composition of Lysis Buffer
Molecular marker techniques have been widely used for cultivar identification of inbred date palms (Phoenix dactylifera L.; Arecaceae) and biodiversity conservation. Isolation of highly pure DNA is the prerequisite for PCR amplification and subsequent use such as DNA fingerprinting and sequencing of genes that have recently been developed for barcoding. To avoid problems related to the preservation and use of liquid nitrogen, we examined sterile sand for grinding the date palm leaves. Individual and combined effects of sodium chloride (NaCl), polyvinylpyrrolidone (PVP) and lithium chloride (LiCl) with the cetyltrimethylammonium bromide (CTAB) method for a DNA yield of sufficient purity and PCR amplification were evaluated in this study. Presence of LiCl and PVP alone or together in the lysis buffer did not significantly improve the DNA yield and purity compared with the addition of NaCl. Our study suggested that grinding of date palm leaf with sterile sand and inclusion of NaCl (1.4 M) in the lysis buffer without the costly use of liquid nitrogen, PVP and LiCl, provides a DNA yield of sufficient purity, suitable for PCR amplification
Serum ferritin levels, socio-demographic factors and desferrioxamine therapy in multi-transfused thalassemia major patients at a government tertiary care hospital of Karachi, Pakistan
<p>Abstract</p> <p>Background</p> <p>Beta thalassemia is the most frequent genetic disorder of haemoglobin synthesis in Pakistan. Recurrent transfusions lead to iron-overload manifested by increased serum Ferritin levels, for which chelation therapy is required.</p> <p>Findings</p> <p>The study was conducted in the Pediatric Emergency unit of Civil Hospital Karachi after ethical approval by the Institutional Review Board of Dow University of Health Sciences. Seventy nine cases of beta thalassemia major were included after a written consent. The care takers were interviewed for the socio-demographic variables and the use of Desferrioxamine therapy, after which a blood sample was drawn to assess the serum Ferritin level. SPSS 15.0 was employed for data entry and analysis.</p> <p>Of the seventy-nine patients included in the study, 46 (58.2%) were males while 33 (41.8%) were females. The mean age was 10.8 (± 4.5) years with the dominant age group (46.2%) being 10 to 14 years. In 62 (78.8%) cases, the care taker education was below the tenth grade. The mean serum Ferritin level in our study were 4236.5 ng/ml and showed a directly proportional relationship with age. Desferrioxamine was used by patients in 46 (58.2%) cases with monthly house hold income significant factor to the use of therapy.</p> <p>Conclusions</p> <p>The mean serum Ferritin levels are approximately ten times higher than the normal recommended levels for normal individuals, with two-fifths of the patients not receiving iron chelation therapy at all. Use of iron chelation therapy and titrating the dose according to the need can significantly lower the iron load reducing the risk of iron-overload related complications leading to a better quality of life and improving survival in Pakistani beta thalassemia major patients.</p> <p>Conflicts of Interest: None</p
Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis
BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London
Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study
Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world.
Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231.
Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001).
Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication
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