121 research outputs found

    ONLINE APPROXIMATION ASSISTED MULTIOBJECTIVE OPTIMIZATION WITH HEAT EXCHANGER DESIGN APPLICATIONS

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    Computer simulations can be intensive as is the case in Computational Fluid Dynamics (CFD) and Finite Element Analysis (FEA). The computational cost can become prohibitive when using these simulations with multiobjective design optimization. One way to address this issue is to replace a computationally intensive simulation by an approximation which allows for a quick evaluation of a large number of design alternatives as needed by an optimizer. This dissertation proposes an approach for multiobjective design optimization when combined with computationally expensive simulations for heat exchanger design problems. The research is performed along four research directions. These are: (1) a new Online Approximation Assisted Multiobjective Optimization (OAAMO) approach with a focus on the expected optimum region, (2) a new approximation assisted multiobjective optimization with global and local metamodeling that always produces feasible solutions, (3) a framework that integrates OAAMO with multiscale simulations (OAAMOMS) for design of heat exchangers at the segment and heat exchanger levels, and (4) applications of OAAMO combined with CFD for shape design of a header for a new generation of heat exchangers using Non-Uniform Rational B-Splines (NURBS). The approaches developed in this thesis are also applied to optimize a coldplate used in electronic cooling devices and different types of plate heat exchangers. In addition many numerical test problems are solved by the proposed methods. The results of these studies show that the proposed online approximation assisted multiobjective optimization is an efficient approach that can be used to predict optimum solutions for a wide class of problems including heat exchanger design problems while reducing significantly the computational cost when compared with existing methods

    Towards Standardized, Safe and Efficacious Screening Approaches to Patients with Lower Extremity Peripheral Arterial Disease in the setting of Lower Extremity Arthroplasty

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    INTRODUCTION: Peripheral arterial disease (PAD) impedes recovery from lower extremity arthroplasties (LEA) and increases risk of complications/mortality, yet there aren’t standards for screening PAD patients pre-LEA. This review proposes some. METHODS: This review searched databases for articles containing relevant terms. Non-English articles, those unrelated to LEA, and duplicates were excluded. Articles were cross-referenced to find other relevant papers for a total of 111. RESULTS: Up to 49.2% of PAD patients have CAD. Wagner grade III/IV ulcers increase amputations and decrease wound closures. The Wound, Ischemia, and Foot Infection (WIfI) system provides more accurate, and therefore actionable, assessment. Overlooking PAD in surgery patients is linked to sequelae from tourniquets. Arterial calcification increases risk of perioperative blood loss from vascular compression, anemia, and critical limb ischemia. Compounding risk factors for PAD (diabetes, smoking, etc.) increase likelihood of future PAD diagnosis. If SBP\u3e180 or DBP\u3e110 mmHg, forgo elective surgery. Non-cardiac surgery patients with hypertension should receive a beta-blocker one day pre-surgery and perioperatively. Smoking cessation four weeks preoperatively and abstinence four weeks postoperatively may halve wound complications. Absent/asymmetrical pulses should prompt vascular referral pre-LEA. ABI may be falsely normal in asymptomatics with moderate aortoiliac stenosis. Risk of hematoma formation and LEA infection suggests waiting one year while continuing antiplatelet therapy. DISCUSSION/CONCLUSIONS: Adequate blood flow is imperative peri- and postoperatively for optimal healing from LEA. Before orthopedic surgery, we suggest meticulous history and assessment to identify PAD risk factors and determine tolerance for surgical intervention. Patients should be stratified for amputation risk and revascularization benefit using the WIfI system. ABI should be performed to assess severity of vascular stenosis. Patients \u3c0.9 should receive vascular consultation, then reassessment. These recommendations could help clinicians assign vascular intervention pre-LEA, minimize complications/reoperations, truncate spending, and improve patient satisfaction/well-being

    EFFECT OF MOST COMMON ANTIBIOTICS AGAINST BACTERIA ISOLATED FROM SURGICAL WOUNDS IN ADEN GOVERNORATE HOSPITALS, YEMEN

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    Objective: The increased antibiotics resistance of pathogenic bacteria isolated from surgical wound is the major health threats challenge the patients especially in developing countries like Yemen. This work was aimed to determine and identify the bacteria associated with surgical wound infections and their resistance to commonly used antibiotics. Methods: One hundred and twenty swabs were sampled from surgical wound patients at Aden City, Yemen. The pathogenic bacteria were isolated and identified according to standard microbiological methods. Also, antibiotic susceptibility tests were determining by using Kirby-Bauer disc diffusion technique. Results: The results showed that out of 120 samples, 68 (56.67%) showed bacterial growth. It was found that the most isolated bacteria was Sylococcus aureus 27 (39.70%) followed by Escherichia coli 19(27.94%), Pseudomonas aeruginosa 13 (19.12%), and Proteus mirabilis 9 (13.24%). All isolated bacteria were recorded to be extremely resistant to the most tested antibiotics. S. aureus was reported to be susceptible to cefotaxime, vancomycin, and ciprofloxacin and highly resistant to ceftazidime, nalidixic acid, erythromycin, and tetracycline. The E. coli isolates showed resistance (100%) to vancomycin and tetracycline and moderately sensitive to ceftazidime and gentamycin. P. aeruginosa showed from high to moderate resistance to most tested antibiotics except gentamycin and cefotaxime. Most of P. mirabilis isolates were sensitive to ceftazidime, cefotaxime, ciprofloxacin, and gentamycin and highly resistant to amoxicillin, erythromycin, and vancomycin. Conclusion: The current study findings that the reduced sensitivity of isolated bacteria to commonly used antibiotics is an alarming and threat upsurge of infections caused by antibiotic-resistant bacteria.                          Peer Review History: Received 27 January 2020;   Revised 15 February; Accepted 1 March, Available online 15 March 2020 Academic Editor: Dr. Amany Mohamed Alboghdadly, Princess Nourah bint abdulrahman university, Riyadh, [email protected] UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency. Received file:                Reviewer's Comments: Average Peer review marks at initial stage: 6.0/10 Average Peer review marks at publication stage: 7.5/10 Reviewer(s) detail: Dr. Mujde Eryilmaz, Ankara University,Turkey, [email protected] Rola Jadallah, Arab American University, Palestine, [email protected] Similar Articles: BACTERIAL CONTAMINATION OF DIALYSIS WATER AND DIALYSATE AT MUKALLA ARTIFICIAL KIDNEY CENTER IN MUKALLA CITY - HADHRAMAUT - YEMEN: RATE OF CONTAMINATION AND SENSITIVITY OF BACTERIAL ISOLATES TO ANTIBIOTICS BIOFILM FORMATION AND ANTIBIOTIC SUSCEPTIBILITY OF UROPATHOGENS IN PATIENTS WITH CATHETER ASSOCIATED URINARY TRACT INFECTIONS IN IBB CITY -YEMEN ANTIMICROBIAL ACTIVITIES FOR HADHRAMI HONEY ON GROWTH OF SOME PATHOGENIC BACTERI

    CAUSES AND MANAGEMENT OF VIRAL EYE INFECTION

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    Introduction: The eye is a fascinating organ for several reasons. It is not only have a composite structure, however it is considered an immune-privileged organ. The anatomy of the eye is composed of the anterior and posterior parts, the line of division is posterior to the lens. The anterior chamber lies within the anterior segment and is an immuneprivileged anatomical location, this is due to the fact that the T-cell response in this area is suppressed This protects the eye from potentially destructive immune attacks however it also makes defence against infectious agents challenging, particularly where T-cell responses are critical for immunological defence. Viruses could get into the eye by direct inoculation, or through haematogenous or neuronal spread. The diagnoses of viral eye infections are usually clinical one, helped by taking a thorough history and performing ophthalmic examination. But in challenging cases the lab tests are essential. In this review, we will discuss the most recent evidence regarding Causes and management of viral eye infection Aim of work: In this review, we will discuss the most recent evidence regarding Causes and management of viral eye infection Methodology: We did a systematic search for Causes and management of viral eye infection using PubMed search engine (http://www.ncbi.nlm.nih.gov/) and Google Scholar search engine (https://scholar.google.com). All relevant studies were retrieved and discussed. We only included full articles. Conclusions: A wide range of of viruses can affect the eye and cause viral eye infections, either as a primary infection or reactivation. Some affect the eye directly while the others indirectly but may still manifest with eye disease. One virus may affect several parts of the eye, while different viruses may cause the same eye disease. This could complicate the clinical diagnosis of viral eye disease, but the lab tests like PCR and antibody tests could assist in challenging cases where there may be diagnostic dilemma. The HIV epidemic has had an huge impact on ophthalmology clinics, this is because the virus can cause different eye diseases, and the associated decrease in cell-mediated immunity makes the person highly susceptible to opportunistic viral eye infections, sometimes with severe morbidity. There could be other viruses that may affect the eye that we did not discuss. Key words: Causes, management, viral eye infection

    Overview on Blood Transfusion-Transmitted Diseases

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    As it is important for the Blood transfusion to be extremely safe, some measures have to be taken long safeguarded the blood supply from the major transfusion transmissible diseases (TTIs).  The risk of transfusion-transmitted infection (TTI) rises with the number of donors exposed, and the effects of TTI are frequently more severe in immune compromised people. TTIs (hepatitis B virus [HBV], HIV, and hepatitis C virus [HCV]) are examples of typical transfusion-transmitted infectious agents. As a result of the gradual application of nucleic acid-amplification technology (NAT) screening for HIV, HCV, and HBV, the residual risk of infected window-period donations has been minimized. Nonetheless, infections emerge far more frequently than is commonly acknowledged, needing ongoing surveillance and individual assessment of transfusion-associated risk. Although there is a constant need to monitor present dangers owing to established TTI, the ongoing issues in blood safety are mostly related to surveillance for developing agents, as well as the creation of quick reaction systems when such agents are detected

    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

    Mapping 123 million neonatal, infant and child deaths between 2000 and 2017

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    Since 2000, many countries have achieved considerable success in improving child survival, but localized progress remains unclear. To inform efforts towards United Nations Sustainable Development Goal 3.2—to end preventable child deaths by 2030—we need consistently estimated data at the subnational level regarding child mortality rates and trends. Here we quantified, for the period 2000–2017, the subnational variation in mortality rates and number of deaths of neonates, infants and children under 5 years of age within 99 low- and middle-income countries using a geostatistical survival model. We estimated that 32% of children under 5 in these countries lived in districts that had attained rates of 25 or fewer child deaths per 1,000 live births by 2017, and that 58% of child deaths between 2000 and 2017 in these countries could have been averted in the absence of geographical inequality. This study enables the identification of high-mortality clusters, patterns of progress and geographical inequalities to inform appropriate investments and implementations that will help to improve the health of all populations

    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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