77 research outputs found

    Testing The Noise Rejection Capability Of The Inversion Based Fourier Transformation Algorithm Applied To 2d Synthetic Geomagnetic Datasets

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    For signal processing, different algorithms can be applied to enhance the quality of measured datasets that contain simple or complex noises during the field survey. Treating these noisy data can be done using the discrete Fourier transform (DFT based noise filtering) which converts the data from time to a frequency domain but in some cases is not preferable due to its low noise suppression capability. Therefore, a robust and effective 2D inversion called the iteratively reweighted least-squares Fourier transformation (IRLS-FT) method is applied. In the framework of this inversion, the continuous Fourier spectrum is discretized using the series expansion to solve our inverse problem in the form of the expansion coefficients. Moreover, the Hermite functions are used as basis functions with the distinguishing feature of the Fourier transform eigenfunctions to facilitate and speed up the calculation of the Jacobian matrix without complex integration. In the robust inversion studied in the article, the Steiner weights are calculated through an internal iteration loop instead of Cauchy weights to overcome the problem of scale parameters. In this paper, the 2D IRLS-FT inversion method is applied to synthetic magnetic datasets and their reduction to the pole. The results demonstrated that the method is very stable during the procedures as well as its robustness, resistance, and effectiveness in the process of noise rejection

    Patient Optimization is the Key in Surgical Repair of Ruptured Umblical Hernia in Cirrhotic Patients and Tense Ascitis

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    Background: Ulceration, leakage, and rupture are considered as the most common complications of umbilical hernias in patients with refractory ascites due to advanced cirrhosis. We aim to determine optimal management and outcome after umbilical herniorrhaphy or hernioplasty in those patients

    Predictors of high calcium score in patients with negative myocardial perfusion imaging

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    Background: Coronary artery disease (CAD) is one of the major cardiovascular diseases. Myocardial perfusion imaging (MPI) using single photon emission computed tomography (SPECT) plays an important role in the diagnosis and prognosis of CAD.Objective: The aim of the present study was to reduce the generalization of doing calcium score for all coronary cardiac patients with negative myocardial perfusion imaging. Patients and methods: A retrospective cohort study analysis using data from Alfa Scan Center, a major outpatient radiology center in Cairo, Egypt, and conducted in Cardiology Department, Faculty of Medicine, Zagazig University that included a total sample of 1168 participants with negative myocardial perfusion imaging not known to have history of CAD, and age ranged between 20 to 80 years from both sexes. All patients were subjected for SPECT-MPI after the intravenous injection of 99mTc-sestamibi.Results: There was statistically significant difference between the two groups regarding age, gender, weight, chest pain, hypertension, dyslipidemia, diabetes, family history of CAD, beta blockers, aspirin, resting diastolic blood pressure (DBP), rest ECG abnormalities and exercise duration. Age, gender, diabetes mellitus and dyslipidemia were the predictors of any coronary artery calcification (CAC > 0) in patients with negative myocardial perfusion imaging. Age, gender and Duke Treadmill Score were the predictors of significant coronary artery calcification (CAC > 100) in patients with negative myocardial perfusion imaging.Conclusion: Calcium score for all not known coronary cardiac patients with negative MPI is a mandatory, particularly if they are old, male gender and have multiple risk factors

    The serum thyroid hormone profile in mechanically ventilated children: Does euthyroid sick syndrome exist?

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    Background: The term "euthyroid sick syndrome" refers to alterations in thyroid function testing during critical illness. Mechanically ventilated children's thyroid hormone levels may be altered, although the reason for this remains a mystery.Objective: This study was aimed to evaluate thyroid hormone profile in mechanically ventilated children and their correlation with mortality.Patients and Methods: Thirty-four mechanically ventilated children were enrolled in a prospective cohort study. On the first and third days of mechanical ventilation, serum TSH, FT3, FT4 and reverse T3 were measured.Results: The mean age of the studied patients was of 31.06 ± 35.94 months. After three days of mechanical ventilation, the serum levels of FT3 and FT4 in the blood were significantly lower than the serum levels on the first day. The serum reverse T3 levels increased significantly on the third day of mechanical ventilation compared to the first day. There was a statistically significant increase in the number of patients with low FT3 and FT4 serum levels on the third day compared to the first day. Twenty-two patients (64.7%) died, and the frequency of low FT3 among dead patients was signiisignificantlycantly higher than among surviving patients.Conclusions: It could be concluded that the mechanically ventilated children had signs of euthyroid sick syndrome, shown by low levels of FT3 and FT4 and a rise in rT3 without a compensatory rise in TSH. Serum FT3 and FT4 decreased, but reverse T3 increased, on the third day of mechanical ventilation compared to the first day. Patients who had low FT3 levels died at a higher rate

    Influence of blended powders on properties of ultra-high strength fibre reinforced self compacting concrete subjected to elevated temperatures

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    Ultra-High Strength Fibre Reinforced Self Compacting Concrete (UHSFRSCC) is in great demand for use in construction projects around the globe. Unless fillers are utilized in this concrete, its production will come at an excessive environmental cost due to the high Carbon footprint of Portland cement. A gap in the published literature was identified, where quaternary mixes, containing Portland cement with three fillers, incorporating fibres, and achieving ultra high strength, were not cited. In this study ternary and quaternary mixes were designed and produced, satisfying the European Guidelines for SCC, with compressive strengths exceeding 115 MPa. Some mixes had compressive strengths between 125 – 150 MPa, which were not previously reported in the literature. The mixes contained Silica Fume (SF), Metakaolin (MK), Limestone powder (LS) as partial Portland cement replacement and quartz powder (QP) as partial sand replacement. Basalt Fibres were added to reinforce the matrix. Compressive & tensile strength of the mixes along with UPV, sorptivity, absorption and SEM Micro-structure features were studied at ambient temperature and after the samples were exposed to either 200 or 300 oC; since the behavior of HSC at elevated temperature is always a cause for concern. The active and inert fillers exhibited a synergic behavior at all temperature conditions. The mix containing: 15% SF, 5% MK, 20% LS and 34% QP achieved the best performance. Compressive and splitting tensile strength improve by 10% and 17% while sorptivity and absorption decline by 40% and 29% respectively at ambient temperature. Residual compressive strength improved by 10% and 19% while, residual splitting tensile strength significantly increases by 21% and 28% after exposure to elevated temperatures 200°C and 300°C respectively. Meanwhile, residual sorptivity decreases by 39% and 38% after exposure to these elevated temperatures. Microstructure properties supported and agreed with the mechanical and permeation characteristics results. The results will contribute to the development of UHSFRSCC in hot weather countries

    A prospective multicentre study evaluating the outcomes of the abdominal wall dehiscence repair using posterior component separation with transversus abdominis muscle release reinforced by a retro-muscular mesh: filling a step

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    Background This study aimed to evaluate the results of posterior component separation (CS) and transversus abdominis muscle release (TAR) with retro-muscular mesh reinforcement in patients with primary abdominal wall dehiscence (AWD). The secondary aims were to detect the incidence of postoperative surgical site occurrence and risk factors of incisional hernia (IH) development following AWD repair with posterior CS with TAR reinforced by retromuscular mesh. Methods Between June 2014 and April 2018, 202 patients with grade IA primary AWD (Björck’s first classification) following midline laparotomies were treated using posterior CS with TAR release reinforced by a retro-muscular mesh in a prospective multicenter cohort study. Results The mean age was 42 ± 10 years, with female predominance (59.9%). The mean time from index surgery (midline laparotomy) to primary AWD was 7 ± 3 days. The mean vertical length of primary AWD was 16 ± 2 cm. The median time from primary AWD occurrence to posterior CS + TAR surgery was 3 ± 1 days. The mean operative time of posterior CS + TAR was 95 ± 12 min. No recurrent AWD occurred. Surgical site infections (SSI), seroma, hematoma, IH, and infected mesh occurred in 7.9%, 12.4%, 2%, 8.9%, and 3%, respectively. Mortality was reported in 2.5%. Old age, male gender, smoking, albumin level < 3.5 gm%, time from AWD to posterior CS + TAR surgery, SSI, ileus, and infected mesh were significantly higher in IH. IH rate was 0.5% and 8.9% at two and three years, respectively. In multivariate logistic regression analyses, the predictors of IH were time from AWD till posterior CS + TAR surgical intervention, ileus, SSI, and infected mesh. Conclusion Posterior CS with TAR reinforced by retro-muscular mesh insertion resulted in no AWD recurrence, low IH rates, and low mortality of 2.5%. Trial registration Clinical trial: NCT05278117

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    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

    Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey

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    Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10 years; 78.2% included were male with a median age of 37 years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020

    Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

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    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
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