46 research outputs found

    Third Order Hamiltonian for a Binary System with Varying Masses Including Preastron Effect

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    This work concerns of the effects of the variation in the masses for two attracting bodies on the orbiter orbital elements. The formulation of the problem was done in different kind of mechanics, Newtonian, Lagrangian, and Hamiltonian. Moreover, constructing the Hamiltonian function of the varying masses of a binary system including, periastron effect, in canonical form in the extended phase space, up to third order of the small parameter ?, to be able to solve using canonical perturbation techniques. Canonical perturbation method based on Lee transformation was developed by Kamel used to remove the short periodic terms from the Hamiltonian to be able to solve the system of equations. The Hamiltonian of the system was transformed to the extended phase space by introducing two variable represents the variation of the masses and their conjugate momenta. Finally, Hamilton's equation of motions was used to drive general formula to calculate the variations in the elements due to the variations in their masses and what so called periastron effects

    Transfusion transmitted virus and dengue virus among healthy blood donors: A prevalence report from Jordan

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    Transfusion transmitted virus (TTV) is thought to contribute to non-A non-E hepatitis and other diseases. Dengue virus (DENV) is a serious mosquito-borne pathogen. Reports on TTV and DENV in Jordan and the Middle East and North Africa region are limited. Herein, the prevalence of TTV antigen and anti-DENV IgG antibodies among apparently healthy blood donors from Northern Jordan and the Northern Agwar region of Jordan was investigated using an enzyme-linked immunosorbent assay. Chi-square test and binary logistic regression were used to correlate positivity with possible infection risk factors (age, sex, residence location, and occupation). One hundred ninety apparently healthy blood donors were included in the study (age 18 - 54 years). TTV antigen was detected in 17.9% of the samples. Lower antigen positivity was observed among Agwar residents than non-residents (7.1% vs 24.5%; chi-square test P < 0.001), which was confirmed by regression analysis (odds ratio 0.262 [95% confidence interval 0.086-0.805]; P = 0.019). Antigen positivity did not differ by age, sex, or occupation. Seropositivity for anti-DENV IgG was 17.9%. Seropositivity did not differ by age, sex, or occupation. Higher seropositivity was observed among Agwar residents than non-residents (36.1% vs 9.4%; chi-square test P < 0.001), which was confirmed by regression analysis (odds ratio 5.420 [95% confidence interval 2.377-12.359]; P < 0.001). Overall, low TTV antigen prevalence and DENV seroprevalence were found among blood donors from Northern Jordan and the Northern Agwar region of Jordan

    Transfusion transmitted virus and dengue virus among healthy blood donors: A prevalence report from Jordan

    Get PDF
    Transfusion transmitted virus (TTV) is thought to contribute to non-A non-E hepatitis and other diseases. Dengue virus (DENV) is a serious mosquito-borne pathogen. Reports on TTV and DENV in Jordan and the Middle East and North Africa region are limited. Herein, the prevalence of TTV antigen and anti-DENV IgG antibodies among apparently healthy blood donors from Northern Jordan and the Northern Agwar region of Jordan was investigated using an enzyme-linked immunosorbent assay. Chi-square test and binary logistic regression were used to correlate positivity with possible infection risk factors (age, sex, residence location, and occupation). One hundred ninety apparently healthy blood donors were included in the study (age 18 - 54 years). TTV antigen was detected in 17.9% of the samples. Lower antigen positivity was observed among Agwar residents than non-residents (7.1% vs 24.5%; chi-square test P < 0.001), which was confirmed by regression analysis (odds ratio 0.262 [95% confidence interval 0.086-0.805]; P = 0.019). Antigen positivity did not differ by age, sex, or occupation. Seropositivity for anti-DENV IgG was 17.9%. Seropositivity did not differ by age, sex, or occupation. Higher seropositivity was observed among Agwar residents than non-residents (36.1% vs 9.4%; chi-square test P < 0.001), which was confirmed by regression analysis (odds ratio 5.420 [95% confidence interval 2.377-12.359]; P < 0.001). Overall, low TTV antigen prevalence and DENV seroprevalence were found among blood donors from Northern Jordan and the Northern Agwar region of Jordan

    Hydrogen underground storage efficiency in a heterogeneous sandstone reservoir

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    Underground hydrogen storage has been recognized as a key technology for storing enormous amounts of hydrogen, thus aiding in the industrial-scale application of a hydrogen economy. However, underground hydrogen storage is only poorly understood, which leads to high project risk. This research thus examined the effect of caprock availability and hydrogen injection rate on hydrogen recovery factor and hydrogen leakage rate to address some fundamental questions related to underground hydrogen storage. A three dimensional heterogeneous reservoir model was developed, and the impact of caprock and hydrogen injected rate on hydrogen underground storage efficiency were analysed with the model. The results indicate that both caprock and injection rate have an important impact on hydrogen leakage, and the quantities of trapped and recovered hydrogen. It is concluded that higher injection rate increases H2 leakage when caprocks are absent. In addition, lower injection rates and caprock availability increases the amount of recovered hydrogen. This work therefore provided fundamental information regarding underground hydrogen storage project assessment, and supports the decarbonisation of the energy supply chain.Cited as: Mahdi, D. S., Al-Khdheeawi, E. A., Yuan, Y., Zhang, Y., Iglauer, S. Hydrogen underground storage efficiency in a heterogeneous sandstone reservoir. Advances in Geo-Energy Research, 2021, 5(4): 437-443, doi: 10.46690/ager.2021.04.0

    Investigation of infill wall effect on inelastic response of structures

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    Experience of recent earthquake proved that infill wall contributes to the behaviour of structures subjected to earthquake or any vibration loads. Although the infill wall is not considered during design process, as it is not a structural element. However, the function of infill wall during vibration of building has not been investigated comprehensively. Therefore, in this study, the influence of RC infill wall on seismic performance of the RC building during earthquake excitation is evaluated. For this purpose, a four-storey building; with and without RC infill wall elements is considered and finite element model is developed to study the influence of this RC infill wall in seismic response of building. Linear static, linear dynamic, nonlinear static (push over) and nonlinear dynamic (time history) analyses were all applied to the specified model for developing the finite element model of this building. On the other hand, an experimental study was carried out to verify the influence of the RC infill wall on the RC frame. The results indicated that utilizing RC infill wall can improve the response of the framed structure effectively during earthquake occurrence. It was also observed that adding infill wall in the outside bays of the four-storey building decreased the displacement of the structural nodes both in x and y directions and decreased their rotation around they and z axis. In addition, addition of RC infill walls reduced the axial forces in the columns and beams in the whole structure. Besides, a clear reduction in the shear forces was observed in the columns and beams. The moment around the beams and columns along the z axis was reduced after addition of the RC infill walls

    Analytical examination of dynamic elements in modern architectural facades for advanced structural aesthetics

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    Introduction: The visual appeal and distinctiveness of a building’s external appearance can be enhanced by incorporating aesthetically pleasing and structurally coherent components, such as diagrids and external bracings. These components not only contribute to the building’s visual appeal but also communicate its structural logic. The aim of this research is to investigate how architectural surfaces can contribute to a building’s urban identity by integrating visually appealing and structurally sound structural systems.Methods: The research focuses on analyzing and understanding the formal structure, generating diverse patterns, and assessing their impact on stability. The goal is to develop architectural surface components that are both aesthetically pleasing and proficient in their application. The study involves analyzing architectural projects that address surfaces in alignment with structural connections and various connecting and modulating mechanisms. Significant architectural achievements from different historical periods were examined to construct a comprehensive knowledge framework.Results: The research conducted a detailed analytical and descriptive investigation into the intricate mechanisms of form surfaces within Modernity and Deconstruction architecture and their impact on structural relationships. The study revealed that by integrating structural connections and modulating mechanisms, it is possible to create architectural surface components that enhance a building’s visual appeal, artistic expression, and urban identity while maintaining structural stability and balance.Conclusion: The research concludes that integrating structural connections and modulating mechanisms into architectural surface components can significantly enhance a building’s visual appeal, artistic expression, and urban identity. By developing aesthetically pleasing and structurally sound elements, such as diagrids and external bracings, architects can create buildings that not only communicate their structural logic but also contribute to the overall urban fabric. This study provides valuable insights for architects and designers seeking to enhance the visual and structural qualities of their buildings

    Assessment of knowledge, attitude, and practice toward first aid management of choking hazards among Eastern Province Saudi adults: an observational study

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    Background and aimChildhood choking is a global health concern that mainly affects children under the age of 5 years. The parent’s and caretaker’s responsibility is critical in the children’s lives and can potentially influence the result of at-home injuries such as choking. We aimed to assess the knowledge, attitude, practice, and associated factors of first aid management toward choking hazards among Saudi adults from the Eastern Province.MethodsThe present analytical study was carried out among 390 Saudi adults attending different primary health centers in the Eastern Province of Saudi Arabia. We used a standard and validated data research topic tool to assess knowledge, attitude, and practice. Spearman’s correlation was applied to determine the correlation between each section, while binomial logistic regression analysis was applied to identify the associated factors.ResultsWe observed knowledge, attitude, and practice scores in 43.3, 38.9, and 36.4% of the participants, respectively. Furthermore, positive correlations between knowledge and attitude (rho = 0.42, p = 0.001), between knowledge and practice (rho = 0.57, p = 0.001), and between attitude and practice (rho = 0.41, p = 0.001) were revealed in our survey. The knowledge of the participants was significantly higher with the age group of 30–40 years [adjusted odds ratio (AOR) = 3.67 (1.94–4.65), p = 0.001] and participants who received training in first aid management [AOR = 1.64 (1.12–2.49), p = 0.037]. This study found that males [AOR = 0.36 (0.21–0.63), p = 0.001] and those working in the private sector [AOR = 0.61 (0.31–0.87), p = 0.018] had significantly lower attitudes.ConclusionOur results underscore the importance of continuous health education initiatives and training courses at primary health care centers regarding first aid management of choking hazards to improve awareness and practices. Furthermore, we recommend prospective multicenter studies to address region-specific knowledge gaps

    The Saudi Critical Care Society practice guidelines on the management of COVID-19 in the ICU: Therapy section

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    BACKGROUND: The rapid increase in coronavirus disease 2019 (COVID-19) cases during the subsequent waves in Saudi Arabia and other countries prompted the Saudi Critical Care Society (SCCS) to put together a panel of experts to issue evidence-based recommendations for the management of COVID-19 in the intensive care unit (ICU). METHODS: The SCCS COVID-19 panel included 51 experts with expertise in critical care, respirology, infectious disease, epidemiology, emergency medicine, clinical pharmacy, nursing, respiratory therapy, methodology, and health policy. All members completed an electronic conflict of interest disclosure form. The panel addressed 9 questions that are related to the therapy of COVID-19 in the ICU. We identified relevant systematic reviews and clinical trials, then used the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach as well as the evidence-to-decision framework (EtD) to assess the quality of evidence and generate recommendations. RESULTS: The SCCS COVID-19 panel issued 12 recommendations on pharmacotherapeutic interventions (immunomodulators, antiviral agents, and anticoagulants) for severe and critical COVID-19, of which 3 were strong recommendations and 9 were weak recommendations. CONCLUSION: The SCCS COVID-19 panel used the GRADE approach to formulate recommendations on therapy for COVID-19 in the ICU. The EtD framework allows adaptation of these recommendations in different contexts. The SCCS guideline committee will update recommendations as new evidence becomes available

    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

    Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

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    Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P &lt; 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely
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