57 research outputs found

    Analysis of RC Continuous Beams Strengthened with FRP Plates: A Finite Element Model

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    Strengthening of reinforced concrete (RC) beams with externally bonded fibre reinforced polymer (FRP) plates/sheets technique has become widespread in the last two decades. Although a great deal of research has been conducted on simply supported RC beams, a few studies have been carried out on continuous beams strengthened with FRP composites.  This paper presents a simple uniaxial nonlinear finite-element model (UNFEM) that is able to accurately estimate the load-carrying capacity and the behaviour of RC continuous beams flexurally strengthened with externally bonded FRP plates on both of the upper and lower fibres. A 21-degree of freedom element is proposed with layer-discretization of the cross-sections for finite element (FE) modelling. Realistic nonlinear constitutive relations are employed to describe the stress-strain behaviour of each component of the strengthened beam. The FE model is based on nonlinear fracture mechanics. The interfacial shear and normal stresses in the adhesive layer are presented using an analytical uncoupled cohesive zone model with a mixed-mode fracture criterion. The results of the proposed FE model are verified by comparison with various selected experimental measurements available in the literature. The numerical results of the plated beams (beams strengthened with FRP plates) agreed very well with the experimental results. The use of FRP increased the ultimate load capacity up to 100 % compared with the non-strengthened beams as occurred in series (S). The major objective of the current model is to help engineers’ model FRP-strengthened RC continuous beams in a simple manner

    Bishop score versus transvaginal ultrasonographic measurement of cervical length in predicting successful labor induction in post-term pregnancy: prospective cohort study

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    Background: The current study aims to compare the efficacy of Bishop score assessment and transvaginal ultrasonographic measurement of the cervical length in prediction of the outcome of labor induction in post-term pregnancy.Methods: A comparative Prospective observational study conducted in Department of Obstetrics and Gynecology, Kom Ombo central hospital from January 2017 to October 2017. Pregnant women were classified into two groups of Bishop Score Group (1): ladies with (Bishop Score 5) = favorable cervix. Also, they were classified into two groups of cervical lengths: Group (1): women with (cervical length <25mm, shorter cervix) and Group (2): those with (cervical length ≥25 mm, longer cervix). The Primary outcome was Bishop score by digital examination and Cervical length by TVS.Results: The study group was 100 women. Regarding sonographic assessment, 44 patients had cervical length <25 mm and the mean cervical length for the whole study group was 25.19±8.16 mm. Successful induction was achieved in 78 patients (78%), while CS was done in 22 patients due to failed induction.  No difference between both groups regarding the parity (p=0.063). When comparing women with successful VD versus those delivered by CS, we found significantly higher Bishop score in the first group 5.12 ± 1.93  vs 3.89 ± 1.71 in the second group (p=0.002). Additionally, VD group had significantly shorter cervix than CS group (22.31 ±7.14 vs. 35.37± 5.80 mm, p=0.007). The Bishop score showed significant moderate negative correlation with the cervical length (r=-0.589, p=0.001).Conclusions: Success of labor induction in women undergoing induction due to prolonged pregnancy can be highly predicted by cervical length as it is more objective and accurate than Bishop Score. The 25 mm cut-off point for cervical length was the best predictor of vaginal delivery

    Quantifying Acoustic and Pressure Sensing for In-Pipe Leak Detection

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    Experiments were carried out to study the effectiveness of using inside-pipe measurements for leak detection in plastic pipes. Acoustic and pressure signals due to simulated leaks, opened to air, are measured and studied for designing a detection system to be deployed inside water networks of 100 mm (4 inch) pipe size. Results showed that leaks as small as 2 l/min can be detected using both hydrophone and dynamic pressure transducer under low pipe flow rates. The ratio between pipe flow rate and leak flow rate seems to be more important than the absolute value of leak flow. Increasing this ratio resulted in diminishing and low frequency leak signals. Sensor location and directionality, with respect to the leak, are important in acquiring clean signal.King Fahd University of Petroleum and Mineral

    Placental pouch closure: a novel, safe and effective surgical procedure for conservative management of placenta accreta

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    Background: Placenta accreta spectrum (PAS) has become a global problem secondary to the high rate of cesarean delivery (CD). The current study presents an effective surgical procedure (placental pouch closure) for uterine preservation in patients with PAS. Methods: We applied this procedure in sixty cases at a tertiary university hospital between September 2017 and January 2019. We included women who were diagnosed as PAS based on preoperative ultrasound and Doppler evaluation, and who had the desire for uterine preservation. Results: The procedure was successful in almost all cases; the uterus was conserved 98.33 % of participants, with no associated severe maternal morbidities or mortality. In all cases, no additional surgical procedures were needed. The mean blood loss was 1263 ml, and the mean number of units of blood required for transfusion was 2.31 units. Conclusion: Identifying and meticulously closing the placental pouch is a novel surgical procedure for conservative management of PAS. In well-selected cases with the availability of facilities and expertise, the technique could have a place as a safe and effective surgical technique in women presenting with placenta accreta who desire uterine preservation. Trial registration number: NCT03241849. Registered on August 8, 201

    Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

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    Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p&lt;0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p&lt;0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised

    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

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

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    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    Behavior of RC beams strengthened in shear with ultra-high performance fiber reinforced concrete (UHPFRC)

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    This paper investigates the behavior of RC beams strengthened in shear with UHPFRC. In order to ensure high quality and facilitate the strengthening process on site applications, it has been considered to apply UHPFRC as a plate pasted on concrete using epoxy. In addition to the control beam, two strengthened RC beams using prefabricated UHPFRC plates were prepared and tested. All beams had the same rectangular cross-section geometry (150mm x 300mm x 2000mm). Two different techniques were considered during the strengthening process; the first application was the addition of two 30 mm UHPFRC plates, whereas the second beam strengthened using one 60 mm UHPFRC plate. Results showed that strengthening RC beams using two UHPFRC plates improved load carrying capacity with 145 % comparing with the control beam. Moreover UHPFRC plate in case of strengthening one side of the RC beam prevented shear cracks from appearing on the strengthened side
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