82 research outputs found

    ASSESSING THE CAPACITY OF FIRE-DAMAGED CONCRETE ELEMENTS USING SECTIONAL ANALYSIS

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    Concrete and steel mechanical properties experience significant deterioration during fire events. Following a fire event, these properties were found to improve with time towards their original values. As a result, the overall capacity of the fire-damaged structure increases after the end of fire exposure. A review of the available models to predict concrete and steel mechanical properties during heating, cooling, and post-cooling stages is conducted in this study. When needed, new models are developed based on the available experimental data. Investigated mechanical properties include concrete compressive strength, tensile strength, initial modulus of elasticity, bond strength, and strains. Yield strength of steel reinforcement is also reviewed to account for their confining effect and contribution to axial and flexural capacities of concrete sections. The study proposes a general stress-strain relationship for concrete that can be used during or after a fire event. This relationship provides an improved knowledge of the safety of concrete structures during or after being exposed to a fire. A heat transfer model based on the Finite Difference Method (FDM) is programmed. The temperature gradient through siliceous square sections is therefore estimated at different heating periods for a standard ASTM-E119 fire. The representative models for concrete thermal properties are given. The temperature distribution obtained using the developed program is validated using available experimental work. Only normal strength concrete is assumed in this study such that spalling problems are less susceptible to occur during the heating period. m A fibrous sectional analysis that can utilize utilizing the proposed material models and the results of the heat transfer model is developed. The predictions of the developed analysis method are compared with other experimental and analytical work for different concrete sections. A good agreement is found between the experimental data and the proposed analysis methodology. The validation includes both deformation and strength criteria. Using the proposed sectional analysis methodology, a total of 24 columns are analyzed to study the effect of different parameters on the axial and flexural capacities of fire- damaged concrete sections. The studied factors are concrete compressive strength, reinforcement ratio, section dimensions, and fire duration. Two columns are added to investigate the effect of the post-cooling age on the overall section capacity. The considered ages are one month and one year after extinguishing the fire. Original axial and flexural capacities are partially recovered after one year due to the continuous regain of concrete and steel mechanical properties during the Post-Cooling stage

    Evaluation Of Platelet-Rich Plasma Effect On Treatment Of Temporomandibular Joint Anterior Disc Displacement

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    The use of Platelet-Rich-Plasma (PRP) may provide a new and improved treatment option for early and late  Temporomandibular Joint (TMJ) disc displacement. However, there are no long-term studies on its use in TMJ arthritis in the literature. The present study evaluate 28 patients with different degrees of disc displacement over a period of time. These patients had experienced no pain reduction following conservative approaches (including splint therapy) and  minimally invasive arthrocentesis treatment. All patients had evidence of disc displacement associated with pain and discomfort, and sometimes clicking. The patients were without systemic joint disease, septicarthritis, or autoimmune arthritis. Only patients who had not responded to conservative therapy were included in the present study. Pain intensity was recorded for each patient using a 0-10 VAS scale. Maximum Inter-incisal Opening (MIO) was also recorded. This assessment was performed at the pretreatment stage and then examinations 3,6,9,12 months respectively after administration of two intra-articular injections of autologous PRP.The results after 12 months revealed that intra-articular injection of autologous PRP appeared to be an effective treatment method for patients with disc displacement in this study. At the 12-months follow-up, all patients  improved their mouth opening significantly. The majority of the PRP patients  showed decreased pain. The average pain score before PRP administration was 7.5, while 3 months after PRP administration the pain score was 4.2. The pain score continued to decrease, reaching nearly 2 after 6 months and  0.5 by the end of 12 months. In conclusion, the use of PRP was found to be an effective and predictable treatment option for disc displacement

    Factors associated with early growth in Egyptian infants: implications for addressing the dual burden of malnutrition.

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    Optimal nutrition is critical to the attainment of healthy growth, human capital and sustainable development. In Egypt, infants and young children face overlapping forms of malnutrition, including micronutrient deficiencies, stunting and overweight. Yet, in this setting, little is known about the factors associated with growth during the first year of life. A rise in stunting in Lower Egypt from 2005 to 2008 prompted this implementation research study, which followed a longitudinal cohort of infants from birth to 1 year of age within the context of a USAID-funded maternal and child health integrated programme. We sought to determine if growth patterns and factors related to early growth differed in Lower and Upper Egypt, and examined the relationship between weight loss and subsequent stunting at 12 months of age. Growth patterns revealed that length-for-age z-score (LAZ) decreased and weight-for-length z-score (WLZ) increased from 6 to 12 months of age in both regions. One-quarter of infants were stunted and nearly one-third were overweight by 12 months of age in lower Egypt. Minimum dietary diversity was significantly associated with WLZ in Lower Egypt (β = 0.22, P \u3c 0.05), but not in Upper Egypt. Diarrhoea, fever and programme exposure were not associated with any growth outcome. Weight loss during any period was associated with a twofold likelihood of stunting at 12 months in Lower Egypt, but not Upper Egypt. In countries, like Egypt, facing the nutrition transition, infant and young child nutrition programmes need to address both stunting and overweight through improving dietary quality and reducing reliance on energy-dense foods

    Factors associated with early growth in Egyptian infants: implications for addressing the dual burden of malnutrition

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    Optimal nutrition is critical to the attainment of healthy growth, human capital and sustainable development. In Egypt, infants and young children face overlapping forms of malnutrition, including micronutrient deficiencies, stunting and overweight. Yet, in this setting, little is known about the factors associated with growth during the first year of life. A rise in stunting in Lower Egypt from 2005 to 2008 prompted this implementation research study, which followed a longitudinal cohort of infants from birth to 1 year of age within the context of a USAID-funded maternal and child health integrated programme. We sought to determine if growth patterns and factors related to early growth differed in Lower and Upper Egypt, and examined the relationship between weight loss and subsequent stunting at 12 months of age. Growth patterns revealed that length-for-age z-score (LAZ) decreased and weight-for-length z-score (WLZ) increased from 6 to 12 months of age in both regions. One-quarter of infants were stunted and nearly one-third were overweight by 12 months of age in lower Egypt. Minimum dietary diversity was significantly associated with WLZ in Lower Egypt (β = 0.22, P < 0.05), but not in Upper Egypt. Diarrhoea, fever and programme exposure were not associated with any growth outcome. Weight loss during any period was associated with a twofold likelihood of stunting at 12 months in Lower Egypt, but not Upper Egypt. In countries, like Egypt, facing the nutrition transition, infant and young child nutrition programmes need to address both stunting and overweight through improving dietary quality and reducing reliance on energy-dense foods

    Sensitive determination of amlodipine besylate using bare/unmodified and DNA-modified screen-printed electrodes in tablets and biological fluids

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    The screen-printed technique is widely used as an efficient tool for electrochemical analysis in environment, clinical and agri-food areas. Significantly, it has the ability to transfer electrochemical laboratory experiments into the field. In the present work, we report a highly sensitive, simple, low-cost protocol for determination of amlodipine (AML) using bare/unmodified and DNA-modified screen-printed electrodes (SPEs). The immobilization of DNA molecules onto SPE offers promising robust and chemically stable molecular wires, which provides a unique opportunity for charge transfer processes. Consequently, the electroanalytical sensing of AML was explored at bare/unmodified and DNA-modified SPEs in a linear range between 0.066–1.0 μM and 0.066–2.0 μM with the detection limit (3σ) found to be 20.70 nM and 14.94 nM, whilst corresponding sensitivities of: 0.43 A L mol−1 and 4.23 A L mol−1 respectively. Although, the superior electrochemical signature of bare SPEs is evident, the immobilization of DNA onto SPEs enhances the sensitivity 10-times more than the bare SPEs. Furthermore, the optimized electroanalytical protocol using the unmodified SPEs, which requires no pre-treatment and electrode modification step, was then further applied to the determination of AML in real samples

    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

    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&nbsp;years; 78.2% included were male with a median age of 37&nbsp;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

    Global economic burden of unmet surgical need for appendicitis

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    Background: There is a substantial gap in provision of adequate surgical care in many low-and middle-income countries. This study aimed to identify the economic burden of unmet surgical need for the common condition of appendicitis. Methods: Data on the incidence of appendicitis from 170 countries and two different approaches were used to estimate numbers of patients who do not receive surgery: as a fixed proportion of the total unmet surgical need per country (approach 1); and based on country income status (approach 2). Indirect costs with current levels of access and local quality, and those if quality were at the standards of high-income countries, were estimated. A human capital approach was applied, focusing on the economic burden resulting from premature death and absenteeism. Results: Excess mortality was 4185 per 100 000 cases of appendicitis using approach 1 and 3448 per 100 000 using approach 2. The economic burden of continuing current levels of access and local quality was US 92492millionusingapproach1and92 492 million using approach 1 and 73 141 million using approach 2. The economic burden of not providing surgical care to the standards of high-income countries was 95004millionusingapproach1and95 004 million using approach 1 and 75 666 million using approach 2. The largest share of these costs resulted from premature death (97.7 per cent) and lack of access (97.0 per cent) in contrast to lack of quality. Conclusion: For a comparatively non-complex emergency condition such as appendicitis, increasing access to care should be prioritized. Although improving quality of care should not be neglected, increasing provision of care at current standards could reduce societal costs substantially

    Pooled analysis of WHO Surgical Safety Checklist use and mortality after emergency laparotomy

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    Background The World Health Organization (WHO) Surgical Safety Checklist has fostered safe practice for 10 years, yet its place in emergency surgery has not been assessed on a global scale. The aim of this study was to evaluate reported checklist use in emergency settings and examine the relationship with perioperative mortality in patients who had emergency laparotomy. Methods In two multinational cohort studies, adults undergoing emergency laparotomy were compared with those having elective gastrointestinal surgery. Relationships between reported checklist use and mortality were determined using multivariable logistic regression and bootstrapped simulation. Results Of 12 296 patients included from 76 countries, 4843 underwent emergency laparotomy. After adjusting for patient and disease factors, checklist use before emergency laparotomy was more common in countries with a high Human Development Index (HDI) (2455 of 2741, 89.6 per cent) compared with that in countries with a middle (753 of 1242, 60.6 per cent; odds ratio (OR) 0.17, 95 per cent c.i. 0.14 to 0.21, P <0001) or low (363 of 860, 422 per cent; OR 008, 007 to 010, P <0.001) HDI. Checklist use was less common in elective surgery than for emergency laparotomy in high-HDI countries (risk difference -94 (95 per cent c.i. -11.9 to -6.9) per cent; P <0001), but the relationship was reversed in low-HDI countries (+121 (+7.0 to +173) per cent; P <0001). In multivariable models, checklist use was associated with a lower 30-day perioperative mortality (OR 0.60, 0.50 to 073; P <0.001). The greatest absolute benefit was seen for emergency surgery in low- and middle-HDI countries. Conclusion Checklist use in emergency laparotomy was associated with a significantly lower perioperative mortality rate. Checklist use in low-HDI countries was half that in high-HDI countries.Peer reviewe
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