| 1. |
- Ademuyiwa, Adesoji O., et al.
(författare)
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Determinants of morbidity and mortality following emergency abdominal surgery in children in low-income and middle-income countries
- 2016
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Ingår i: BMJ Global Health. - : BMJ Publishing Group Ltd. - 2059-7908. ; 1:4
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Tidskriftsartikel (refereegranskat)abstract
- Background: Child health is a key priority on the global health agenda, yet the provision of essential and emergency surgery in children is patchy in resource-poor regions. This study was aimed to determine the mortality risk for emergency abdominal paediatric surgery in low-income countries globally.Methods: Multicentre, international, prospective, cohort study. Self-selected surgical units performing emergency abdominal surgery submitted prespecified data for consecutive children aged <16 years during a 2-week period between July and December 2014. The United Nation's Human Development Index (HDI) was used to stratify countries. The main outcome measure was 30-day postoperative mortality, analysed by multilevel logistic regression.Results: This study included 1409 patients from 253 centres in 43 countries; 282 children were under 2 years of age. Among them, 265 (18.8%) were from low-HDI, 450 (31.9%) from middle-HDI and 694 (49.3%) from high-HDI countries. The most common operations performed were appendectomy, small bowel resection, pyloromyotomy and correction of intussusception. After adjustment for patient and hospital risk factors, child mortality at 30 days was significantly higher in low-HDI (adjusted OR 7.14 (95% CI 2.52 to 20.23), p<0.001) and middle-HDI (4.42 (1.44 to 13.56), p=0.009) countries compared with high-HDI countries, translating to 40 excess deaths per 1000 procedures performed.Conclusions: Adjusted mortality in children following emergency abdominal surgery may be as high as 7 times greater in low-HDI and middle-HDI countries compared with high-HDI countries. Effective provision of emergency essential surgery should be a key priority for global child health agendas.
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| 2. |
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| 3. |
- Thomas, HS, et al.
(författare)
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- 2019
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swepub:Mat__t
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| 4. |
- Tabiri, S, et al.
(författare)
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- 2021
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swepub:Mat__t
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| 5. |
- Bravo, L, et al.
(författare)
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- 2021
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swepub:Mat__t
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| 6. |
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| 7. |
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| 8. |
- Drake, TM, et al.
(författare)
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Surgical site infection after gastrointestinal surgery in children: an international, multicentre, prospective cohort study
- 2020
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Ingår i: BMJ global health. - : BMJ. - 2059-7908. ; 5:12
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Tidskriftsartikel (refereegranskat)abstract
- Surgical site infection (SSI) is one of the most common healthcare-associated infections (HAIs). However, there is a lack of data available about SSI in children worldwide, especially from low-income and middle-income countries. This study aimed to estimate the incidence of SSI in children and associations between SSI and morbidity across human development settings.MethodsA multicentre, international, prospective, validated cohort study of children aged under 16 years undergoing clean-contaminated, contaminated or dirty gastrointestinal surgery. Any hospital in the world providing paediatric surgery was eligible to contribute data between January and July 2016. The primary outcome was the incidence of SSI by 30 days. Relationships between explanatory variables and SSI were examined using multilevel logistic regression. Countries were stratified into high development, middle development and low development groups using the United Nations Human Development Index (HDI).ResultsOf 1159 children across 181 hospitals in 51 countries, 523 (45·1%) children were from high HDI, 397 (34·2%) from middle HDI and 239 (20·6%) from low HDI countries. The 30-day SSI rate was 6.3% (33/523) in high HDI, 12·8% (51/397) in middle HDI and 24·7% (59/239) in low HDI countries. SSI was associated with higher incidence of 30-day mortality, intervention, organ-space infection and other HAIs, with the highest rates seen in low HDI countries. Median length of stay in patients who had an SSI was longer (7.0 days), compared with 3.0 days in patients who did not have an SSI. Use of laparoscopy was associated with significantly lower SSI rates, even after accounting for HDI.ConclusionThe odds of SSI in children is nearly four times greater in low HDI compared with high HDI countries. Policies to reduce SSI should be prioritised as part of the wider global agenda.
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| 9. |
- Dawod, Ahmed, et al.
(författare)
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Efficacy of Ficus sycomorus (Sycamore Fig) Extract on Intestinal Coccidiosis in Experimentally Infected Rabbits
- 2022
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Ingår i: Life. - : MDPI. - 2075-1729. ; 12:6
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Tidskriftsartikel (refereegranskat)abstract
- This study was conducted to investigate the effect of the Ficus sycomorus extract on Eimeria intestinalis in experimentally infected rabbits. For this purpose, forty male 30-day-old rabbits (Blanc de Bouscat) were divided into four groups (n = 10 in each group). Rabbits kept in the first group served as negative control (non-treated-non-infected). Rabbits kept in the second, third, and fourth groups were challenged at 10 weeks old with 3 x 10(4) E. intestinalis sporulated oocysts. The third and fourth groups were treated orally with diclazuril 10% (0.05 mg/kg body weight) and F. sycomorus (100 mg/Kg) for three consecutive days, respectively. The efficacy was assessed based on the growth performance parameters, clinical symptoms, oocyst shedding, histopathological findings, and hematological parameters for 16 days post challenge. The study revealed that rabbits treated with F. sycomorus methanolic extract and diclazuril showed mild clinical symptoms with a significant decrease in oocyst shedding compared with the positive control. Moreover, the diclazuril-treated group showed the highest leukocytic count and the lowest monocytes percentage compared with other groups. Furthermore, the lowest lymphocytes percentage was recorded in the control positive group. Histopathologically, moderate coccidia infestation in the intestinal mucosa and moderate hydropic degeneration of hepatocytes were observed in the diclazuril treated group compared with the negative control. However, mild coccidia infestation in the intestinal mucosa and slight coagulative necrosis of hepatocytes was found in the F. sycomorus treated group. In conclusion, F. sycomorus methanolic extract had promising effects on the live performance, oocyst count, and blood variables, while it possesses adverse consequences on the hepatic tissues. Further studies are required to optimize the dose and extraction method to mitigate its side effects.
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| 10. |
- Dawod, Ahmed, et al.
(författare)
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UPLC-QToF Nanospray MS and NMR Analysis of Ficus sycomorus Stem Bark and Its Effects on Rabbit
- 2021
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Ingår i: Processes. - : MDPI. - 2227-9717. ; 9:7
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Tidskriftsartikel (refereegranskat)abstract
- In the present study, a phytochemical of Ficus sycomorus (Moraceae family) was screened, and the effect of this extract on rabbit performance indices, immunity, and carcass quality measures was determined. Ficus sycomorus samples were collected, air-dried, and extracted with 70% methanol to prepare a solution of 100 mg/mL concentration. The extract was subjected to high-resolution mass spectrometric measurements via ultra-high performance liquid chromatography-quadrupole time-of-flight-nanospray mass spectrometry (UPLC-QToF-MS) and 1H NMR analysis. Forty-eight male rabbits, one-month-old, belonging to the Blanc de Bouscat and New Zealand White breeds were selected and distributed equally in a 2 x 3 factorial trial. The rabbits within each breed received F. sycomorus extract at the dose of 0, 100, and 200 mg/kg for 60 days. Blood samples were collected and serum obtained for the detection of liver enzymes, serum lipids, and proteins. The results of UPLC-QToF-MS and molecular networking analysis revealed the presence of procyanidin B2, procyanidin A1, genistein, eriodyctiol, catechin, luteolin, biochanin A, and chlorogenic acid that might exhibit various pharmaceutical activities. However, the F. sycomorus extract reduced rabbit performance indices and carcass quality measures. In addition, this extract significantly depressed the low-density lipoprotein and triglycerides, which may indicate the antidyslipidemia effect of this extract on rabbits.
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| 11. |
- Elsayed, Mohamed Hammad, et al.
(författare)
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Overcoming small-bandgap charge recombination in visible and NIR-light-driven hydrogen evolution by engineering the polymer photocatalyst structure
- 2024
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Ingår i: Nature Communications. - 2041-1723. ; 15:1
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Tidskriftsartikel (refereegranskat)abstract
- Designing an organic polymer photocatalyst for efficient hydrogen evolution with visible and near-infrared (NIR) light activity is still a major challenge. Unlike the common behavior of gradually increasing the charge recombination while shrinking the bandgap, we present here a series of polymer nanoparticles (Pdots) based on ITIC and BTIC units with different π-linkers between the acceptor-donor-acceptor (A-D-A) repeated moieties of the polymer. These polymers act as an efficient single polymer photocatalyst for H2 evolution under both visible and NIR light, without combining or hybridizing with other materials. Importantly, the difluorothiophene (ThF) π-linker facilitates the charge transfer between acceptors of different repeated moieties (A-D-A-(π-Linker)-A-D-A), leading to the enhancement of charge separation between D and A. As a result, the PITIC-ThF Pdots exhibit superior hydrogen evolution rates of 279 µmol/h and 20.5 µmol/h with visible (>420 nm) and NIR (>780 nm) light irradiation, respectively. Furthermore, PITIC-ThF Pdots exhibit a promising apparent quantum yield (AQY) at 700 nm (4.76%).
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| 12. |
- Khan, Yusra Habib, et al.
(författare)
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Barriers and facilitators of childhood COVID-19 vaccination among parents : A systematic review
- 2022
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Ingår i: Frontiers in Pediatrics. - : Frontiers Media S.A.. - 2296-2360. ; 10
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Forskningsöversikt (refereegranskat)abstract
- BackgroundThe acceptance of vaccination against COVID-19 among parents of young children plays a significant role in controlling the current pandemic. A wide range of factors that influence vaccine hesitancy in adults has been reported worldwide, but less attention has been given to COVID-19 vaccination among children. Vaccine hesitancy is considered a major challenge in achieving herd immunity, and it is more challenging among parents as they remain deeply concerned about their child's health. In this context, a systematic review of the current literature is inevitable to assess vaccine hesitancy among parents of young children to ensure a successful ongoing vaccination program.MethodA systematic search of peer-reviewed English literature indexed in Google Scholar, PubMed, Embase, and Web of science was performed using developed keywords between 1 January 2020 and August 2022. This systematic review included only those studies that focused on parental concerns about COVID-19 vaccines in children up to 12 years without a diagnosis of COVID-19. Following PRISMA guidelines, a total of 108 studies were included. The quality appraisal of the study was performed by Newcastle-Ottawa Scale (NOS).ResultsThe results of 108 studies depict that vaccine hesitancy rates differed globally with a considerably large number of factors associated with it. The highest vaccine hesitancy rates among parents were reported in a study from the USA (86.1%) and two studies from Saudi Arabia (> 85%) and Turkey (89.6%). Conversely, the lowest vaccine hesitancy rates ranging from 0.69 and 2% were found in two studies from South Africa and Switzerland, respectively. The largest study (n = 227,740) was conducted in Switzerland while the smallest sample size (n = 12) was represented by a study conducted in the USA. The most commonly reported barriers to childhood vaccination were mothers' lower education level (N = 46/108, 43%), followed by financial instability (N = 19/108, 18%), low confidence in new vaccines (N = 13/108, 12%), and unmonitored social media platforms (N = 5/108, 4.6%). These factors were significantly associated with vaccine refusal among parents. However, the potential facilitators for vaccine uptake among respondents who intended to have their children vaccinated include higher education level (N = 12/108, 11%), followed by information obtained through healthcare professionals (N = 9/108, 8.3%) and strong confidence in preventive measures taken by the government (N = 5/81, 4.6%).ConclusionThis review underscores that parents around the globe are hesitant to vaccinate their kids against COVID-19. The spectrum of factors associated with vaccine hesitancy and uptake varies across the globe. There is a dire need to address vaccine hesitancy concerns regarding the efficacy and safety of approved vaccines. Local context is inevitable to take into account while developing programs to reduce vaccine hesitancy. There is a dire need to devise strategies to address vaccine hesitancy among parents through the identification of attributing factors.
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| 13. |
- Mallhi, Tauqeer Hussain, et al.
(författare)
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Estimation of Psychological Impairment and Coping Strategies during COVID-19 Pandemic among University Students in Saudi Arabia : A Large Regional Analysis
- 2022
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Ingår i: International Journal of Environmental Research and Public Health. - : MDPI. - 1661-7827 .- 1660-4601. ; 19:21
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Tidskriftsartikel (refereegranskat)abstract
- Background: The COVID-19 pandemic and associated restrictive measures have substantially affected educational processes around the globe, resulting in psychological distress among students. The mental health of students in higher education is of paramount importance, and the COVID-19 pandemic has brought this vulnerable population into renewed focus. In this context, the evaluation of students' mental health at educational institutes has gained invaluable popularity during the COVID-19 pandemic. This study aimed to ascertain the psychological health and coping strategies among students from a higher education institute in Saudi Arabia.Methods: An online study instrument was used to assess anxiety (Generalized Anxiety Disorder-7, GAD-7), depression (Patient Health Questionnaire-9, PHQ-9), post-traumatic stress disorder-PTSD (Impact of Event Scale-Revised, IES-R) and coping strategies (Brief-COPE). The severity of the psychological distress was classified as per the scoring criteria and correlated with demographics using appropriate statistical methods.Results: Of 1074 students (age 21.1 +/- 2.1 years), 12.9% and 9.7% had severe anxiety and depression, respectively. The mean anxiety and depression scores were 7.50 +/- 5.51 and 9.31 +/- 6.72, respectively. About one-third (32%) of students reported suicidal ideation, with 8.4% students having such thoughts nearly every day. The average PTSD score was 21.64 +/- 17.63, where avoidance scored higher (8.10 +/- 6.94) than intrusion and hyperarousal. There was no association of anxiety, depression and PTSD score with the demographics of the study participants. Religious/spiritual coping (5.43 +/- 2.15) was the most adoptive coping mechanism, followed by acceptance (5.15 +/- 2.10). Male students were significantly (p < 0.05) associated with active copings, instrumental support, planning, humor, acceptance and religious coping. Substance use was the least adopted coping strategy but practiced by a considerable number of students.Conclusions: The long-lasting pandemic situation, onerous protective measures and uncertainties in educational procedures have resulted in a high prevalence of psychological ailments among university students, as indicated in this study. These findings accentuate the urgent need for telepsychiatry and appropriate population-specific mental health services to assess the extent of psychological impairment and to leverage positive coping behaviors among students.
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| 14. |
- Mallhi, Tauqeer Hussain, et al.
(författare)
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Incidence, risk factors and outcomes of acute kidney injury among COVID-19 patients : A systematic review of systematic reviews
- 2022
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Ingår i: Frontiers in Medicine. - : Frontiers Media S.A.. - 2296-858X. ; 9
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Forskningsöversikt (refereegranskat)abstract
- The COVID-19 associated acute kidney injury (CAKI) has emerged as a potential intricacy during the management of patients. Navigating the rapidly growing body of scientific literature on CAKI is challenging, and ongoing critical appraisal of this complication is essential. This study aimed to summarize and critically appraise the systematic reviews (SRs) on CAKI to inform the healthcare providers about its prevalence, risk factors and outcomes. All the SRs were searched in major databases (PubMed, EMBASE, Web of Science) from inception date to December 2021. This study followed SR of SRs methodology, all the records were screened, extracted and subjected to quality assessment by assessing the methodological quality of systematic reviews (AMSTAR-2). The extracted data were qualitatively synthesized and tabulated. This review protocol was registered in PROSPERO (CRD42022299444). Of 3,833 records identified; 42 SRs were included in this overview. The quality appraisal of the studies showed that 17 SRs were of low quality, while 8 moderate and 17 were of high-quality SRs. The incidence of CAKI ranged from 4.3% to 36.4% in overall COVID-19 patients, 36%-50% in kidney transplant recipients (KTRs), and up to 53% in severe or critical illness. Old age, male gender, cardiovascular disease, chronic kidney disease, diabetes mellitus and hypertension were frequently reported risk factors of CAKI. The need of renal replacement therapy (RRT) was up to 26.4% in overall COVID-19 patients, and 39% among those having CAKI. The occurrence of acute kidney injury (AKI) was found independent predictor of death, where mortality rate among CAKI patients ranged from 50% to 93%. This overview of SRs underscores that CAKI occurs frequently among COVID-19 patients and associated with high mortality, need of RRT and adverse outcomes. However, the confidence of these results is moderate to low which warrants the need of more SRs having established methodological standards.
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| 15. |
- Akhtar, Muneeba, et al.
(författare)
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Response Surface Methodology (RSM) approach to formulate and optimize the bilayer combination tablet of Tamsulosin and Finasteride
- 2024
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Ingår i: Saudi Pharmaceutical Journal. - : Elsevier. - 1319-0164 .- 2213-7475. ; 32:3
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Tidskriftsartikel (refereegranskat)abstract
- An orally administered bilayer tablet with Tamsulosin (TAM) as the sustained release (SR) and Finasteride (FIN) as immediate release (IR) was manufactured. A response surface methodology was employed to formulate bilayer tablets with individual release layers, i.e., sustained and immediate release (SR and IR). Independent variables selected in both cases comprise hydroxypropyl methylcellulose (HPMC) as SR polymer, and avicel PH102 in the inner layer while Triacetin and talc in the outer layer, respectively. Tablets were prepared by direct compression, a total of 11 formulations were prepared for inner layer TAM, and 9 formulations for outer layer FIN were designed; these formulations were evaluated for hardness, friability, thickness, %drug content, and %drug release. A central composite design was employed in response surface methodology to design and optimize the formulation. The percentage of drug released was evaluated by in-vitro USP dissolution method of optimized formulation for 0.5, 2, and 6 hrs, and results were 24.63, 52.96, and 97.68 %, respectively. Drug release data was plotted in various kinetic models using a D.D solver, where drug release was first order that is concentration dependent and was best explained by Korsmeyer–Peppa kinetics, as the highest linearity was observed (R2 = 0.9693). However, a very close relationship was also noted with Higuchi kinetics (R2 = 0.9358). The mechanism of drug release was determined through the Korsmeyer model, and exponent "n" was found to be 0.4, indicative of an anomalous diffusion mechanism or diffusion coupled with erosion.
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| 16. |
- Alimena, Juliette, et al.
(författare)
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Searching for long-lived particles beyond the Standard Model at the Large Hadron Collider
- 2020
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Ingår i: Journal of Physics G. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 47:9
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Tidskriftsartikel (refereegranskat)abstract
- Particles beyond the Standard Model (SM) can generically have lifetimes that are long compared to SM particles at the weak scale. When produced at experiments such as the Large Hadron Collider (LHC) at CERN, these long-lived particles (LLPs) can decay far from the interaction vertex of the primary proton-proton collision. Such LLP signatures are distinct from those of promptly decaying particles that are targeted by the majority of searches for new physics at the LHC, often requiring customized techniques to identify, for example, significantly displaced decay vertices, tracks with atypical properties, and short track segments. Given their non-standard nature, a comprehensive overview of LLP signatures at the LHC is beneficial to ensure that possible avenues of the discovery of new physics are not overlooked. Here we report on the joint work of a community of theorists and experimentalists with the ATLAS, CMS, and LHCb experiments-as well as those working on dedicated experiments such as MoEDAL, milliQan, MATHUSLA, CODEX-b, and FASER-to survey the current state of LLP searches at the LHC, and to chart a path for the development of LLP searches into the future, both in the upcoming Run 3 and at the high-luminosity LHC. The work is organized around the current and future potential capabilities of LHC experiments to generally discover new LLPs, and takes a signature-based approach to surveying classes of models that give rise to LLPs rather than emphasizing any particular theory motivation. We develop a set of simplified models; assess the coverage of current searches; document known, often unexpected backgrounds; explore the capabilities of proposed detector upgrades; provide recommendations for the presentation of search results; and look towards the newest frontiers, namely high-multiplicity 'dark showers', highlighting opportunities for expanding the LHC reach for these signals.
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| 17. |
- Alyami, Mana, et al.
(författare)
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Estimating compressive strength of concrete containing rice husk ash using interpretable machine learning-based models
- 2024
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Ingår i: Case Studies in Construction Materials. - : Elsevier. - 2214-5095. ; 20
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Tidskriftsartikel (refereegranskat)abstract
- The construction sector is a major contributor to global greenhouse gas emissions. Using recycled and waste materials in concrete is a practical solution to address environmental challenges. Currently, agricultural waste is widely used as a substitute for cement in the production of eco-friendly concrete. However, traditional methods for assessing the strength of such materials are both expensive and time-consuming. Therefore, this study uses machine learning techniques to develop prediction models for the compressive strength (CS) of rice husk ash (RHA) concrete. The ML techniques used in the present study include random forest (RF), light gradient boosting machine (LightGBM), ridge regression, and extreme gradient boosting (XGBoost). A total of 348 values of CS were collected from the experimental studies, and five characteristics of RHA concrete were taken as input variables. For the performance assessment of the models, multiple statistical metrics were used. During the training phase, the correlation coefficients (R) obtained for ridge regression, RF, XGBoost, and LightGBM were 0.943, 0.981, 0.985, and 0.996, respectively. In the testing set, the developed models demonstrated even higher performance, with correlation coefficients of 0.971, 0.993, 0.992, and 0.998 for ridge regression, RF, XGBoost, and LightGBM, respectively. The statistical analysis revealed that the LightGBM model outperformed other models, whereas the ridge regression model exhibited comparatively lower accuracy. SHapley Additive exPlanation (SHAP) method was employed for the interpretability of the developed model. The SHAP analysis revealed that water-to-cement is a controlling parameter in estimating the CS of RHA concrete. In conclusion, this study provides valuable guidance for builders and researchers to estimate the CS of RHA concrete. However, it is suggested that more input variables be incorporated and hybrid models utilized to further enhance the reliability and precision of the models.
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| 18. |
- Alyami, Mana, et al.
(författare)
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Predictive modeling for compressive strength of 3D printed fiber-reinforced concrete using machine learning algorithms
- 2024
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Ingår i: Case Studies in Construction Materials. - : Elsevier. - 2214-5095. ; 20
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Tidskriftsartikel (refereegranskat)abstract
- Three-dimensional (3D) printing in the construction industry is growing rapidly due to its inherent advantages, including intricate geometries, reduced waste, accelerated construction, cost-effectiveness, eco-friendliness, and improved safety. However, optimizing the mixture composition for 3D-printed concrete remains a formidable task, encompassing multiple variables and requiring a comprehensive trial-and-error experimentation process. Accordingly, this study used seven machine learning (ML) algorithms, including support vector regression (SVR), decision tree (DT), SVR-Bagging, SVR-Boosting, random forest (RF), gradient boosting (GB), and gene expression programming (GEP) for forecasting the compressive strength (CS) of 3D printed fiber-reinforced concrete (3DP-FRC). For model development, 299 data points were collected from experimental studies and split into two portions: 70% for model training and 30% for model validation. Various statistical metrics were employed to examine the accuracy and generalizability of the established models. The DT, RF, GB, and GEP models demonstrated higher accuracy in the validation set, achieving correlation (R) values of 0.987, 0.986, 0.986, and 0.98, respectively. The DT, RF, GB, and GEP models exhibited mean absolute error (MAE) scores of 4.644, 3.989, 3.90, and 5.691, respectively. Furthermore, the combination of SVR with boosting and bagging techniques slightly improved the accuracy compared to the individual SVR model. Additionally, the SHapley Additive exPlanations (SHAP) approach unveils the proportional significance of parameters in influencing the CS of 3DP-FRC. The SHAP technique revealed that water, silica fume, superplasticizer, sand content, and loading directions are the dominant parameters in estimating the CS of 3DP-FRC. The SHAP local interpretability unveils the intrinsic relationship between diverse input variables and their impacts on the strength of 3DP-FRC. The SHAP interpretability offers significant insights into the optimum mix proportion of 3DP-FRC.
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| 19. |
- Elsayed, Mohamed Hammad, et al.
(författare)
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Hydrophobic and Hydrophilic Conjugated Polymer Dots as Binary Photocatalysts for Enhanced Visible-Light-Driven Hydrogen Evolution through Forster Resonance Energy Transfer
- 2021
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 13:47, s. 56554-56565
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Tidskriftsartikel (refereegranskat)abstract
- Organic semiconducting polymers exhibited promising photocatalytic behavior for hydrogen (H-2) evolution, especially when prepared in the form of polymer dots (Pdots). However, the Pdot structures were formed using common nonconjugated amphiphilic polymers, which have a negative effect on charge transfer between photocatalysts and reactants and are unable to participate in the photocatalytic reaction. This study presents a new strategy for constructing binary Pdot photocatalysts by replacing the nonconjugated amphiphilic polymer typically employed in the preparation of polymer nanoparticles (Pdots) with a low-molecular-weight conjugated polyelectrolyte. The as-prepared polyelectrolyte/hydrophobic polymer-based binary Pdots truly enhance the electron transfer between the Pt cocatalyst and the polymer photocatalyst with good water dispersibility. Moreover, unlike the nonconjugated amphiphilic polymer, the photophysics and mechanism of this photocatalytic system through time-correlated single-photon counting (TCSPC) and transient absorption (TA) measurements confirmed the Forster resonance energy transfer (FRET) between the polyelectrolyte as a donor and the hydrophobic polymer as an acceptor. As a result, the designated binary Pdot photocatalysts significantly enhanced the hydrogen evolution rate (HER) of 43 900 mu mol g(-1) h(-1) (63.5 mu mol h(-1), at 420 nm) for PTTPA/PFTBTA Pdots under visible-light irradiation.
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| 20. |
- Elsayed, Mohamed Hammad, et al.
(författare)
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Visible-light-driven hydrogen evolution using nitrogen-doped carbon quantum dot-implanted polymer dots as metal-free photocatalysts
- 2021
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Ingår i: Applied Catalysis B: Environmental. - : Elsevier BV. - 0926-3373. ; 283
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Tidskriftsartikel (refereegranskat)abstract
- Given the photocatalytic properties of semiconducting polymers and carbon quantum dots (CQDs), we report a new structure for a metal-free photocatalytic system with a promising efficiency for hydrogen production through the combination of an organic semiconducting polymer (PFTBTA) and N-doped carbon quantum dots (NCQDs) covered by PS-PEGCOOH to produce heterostructured photocatalysts in the form of polymer dots (Pdots). This design could provide strong interactions between the two materials owing to the space confinement effect in nanometer-sized Pdots. Small particle size NCQDs are easy to insert inside the Pdot, which leads to an increase in the stability of the Pdot structure and enhances the hydrogen evolution rate by approximately 5-fold over that of pure PFTBTA Pdots. The photophysics and the mechanism behind the catalytic activity of our design are investigated by transient absorption measurement, demonstrating the role of NCQDs to enhance the charge separation and the photocatalytic efficiency of the PFTBTA Pdot.
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| 21. |
- Hammad, A., et al.
(författare)
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The dark Z ' and sterile neutrinos behind current anomalies
- 2022
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Ingår i: Physics Letters B. - : Elsevier. - 0370-2693 .- 1873-2445. ; 827
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Tidskriftsartikel (refereegranskat)abstract
- We show how, in the B - L extension of the SM (BLSM) with an Inverse Seesaw (IS) mechanism for neutrino mass generation, a light Z' state with moderate couplings to SM objects, hence 'dark' in its nature, can be associated, in conjunction with light sterile neutrinos, to some present day data anomalies, such as the anomalous magnetic moment of the muon as well as a possible signal indicating the existence of sterile neutrinos in neutrino beam experiments.
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| 22. |
- Hammad, Yasser, et al.
(författare)
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Experimental effect of different dilutions of blood with human plasma protein fraction and large dose factor one on blood coagulation and chemistry in vitro
- 2019
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Ingår i: Indian Journal of Anaesthesia. - : Wolters Kluwer. - 0019-5049. ; 63:12, s. 1015-1021
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Tidskriftsartikel (refereegranskat)abstract
- Background and Aims: Human plasma protein fraction 5% (PPF5%) is an albumin-based colloid used to expand the plasma volume during volume deficiency. The current basic medical experimental study assessed in vitro coagulation of PPF5% solution and its effects on blood coagulation and chemistry. Methods: The study involved 20 volunteers, and each volunteer donated 20-50 ml of fresh blood. Three dilutions of blood with PPF5% dilutions were prepared (30, 50, and 70%). The fibrinogen dose required to correct coagulation in the 50% diluted samples was assessed (two doses used). The thromboelastogram (TEG) measured the haemostatic parameters (fibrinogen level, initiation of coagulation [R time], kinetics [K], acceleration of coagulation [α angle], maximum amplitude [MA] and coagulation index [CI]), and the ABL gas analyser measured the blood chemistry changes. Results: All dilutions showed significant TEG and blood chemistry changes when compared to controls. The two doses of fibrinogen corrected the clot formation speed with no significant difference in speed between the two doses. Acidosis measured by the strong ion gap (SID) and pH were significant for all dilutions when compared with the baseline. The 30% dilution remained within the lower normal acceptable value while 50% dilution was beyond the critical normal values. Conclusion: In vitro PPF5% to replace blood loss up to 50% dilution did not have significant coagulation and blood chemistry effects while coagulopathy should be expected in extreme dilutions (70%). Fibrinogen in a dose equivalent to 4 gm/70 kg adult improved clot strength at 50% dilution.
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| 23. |
- Lin, Wei Cheng, et al.
(författare)
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Effect of energy bandgap and sacrificial agents of cyclopentadithiophene-based polymers for enhanced photocatalytic hydrogen evolution
- 2021
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Ingår i: Applied Catalysis B: Environmental. - : Elsevier BV. - 0926-3373. ; 298
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Tidskriftsartikel (refereegranskat)abstract
- A library of donor-acceptor system consisting of cyclopentadithiophene-based polymer photocatalysts have been designed and synthesized. Among all photocatalysts, the active PCPDTBSO achieved hydrogen evolution rates of 24.6 mmol h–1 g–1 with apparent quantum yields of 8.7 % at 500 nm. More importantly, combined the results of photocatalytic efficiency, apparent quantum yield, the time-resolved fluorescence decay spectra, the steady-state photoluminescence spectra, and the transient absorption spectroscopy, and the oxidation potentials of sacrificial donors and protons reduction potentials in different pH values, we confirmed the concept that ascorbic acid is a suitable sacrificial donor for narrow bandgap polymers and triethylamine is a suitable sacrificial donor for wide bandgap polymers owing to the existence of the optimal thermodynamic driving force. We believed this study would be advantageous for the selection of photocatalysts and sacrificial donors for hydrogen production.
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| 24. |
- Mallhi, Tauqeer Hussain, et al.
(författare)
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Evaluation of knowledge and barriers of influenza vaccine uptake among university students in Saudi Arabia : a cross-sectional analysis
- 2022
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Ingår i: PeerJ. - : PeerJ. - 2167-8359. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Background. Influenza vaccine hesitancy is a significant threat to global maneuvers for reducing the burden of seasonal and pandemic influenza. This study estimated the vaccine uptake, barriers, and willingness for influenza vaccines among university students in Saudi Arabia. Methods. A cross-sectional survey was conducted among health science (HS) and non-health science (NHS) university students. A 31-item questionnaire was used to ascertain the vaccination rate, barriers, and willingness for the flu vaccine. Results. This study included 790 students (mean age: 21.40 +/- 1.94 years), 246 (31.1%) from HS and 544 (68.9%) from NHS disciplines. About 70% did not take flu shots before the arrival of the winter. The mean knowledge score was 7.81 +/- 1.96, where 20.4%, 67.6%, and 12% of respondents had good, moderate, and poor knowledge regarding flu vaccines. The relative importance index (RII) analysis showed a lack of recommendation from physicians (51.5%, RI ranked: 1) was a top-ranked barrier to vaccine uptake, followed by negative perceptions and accessibility issues. Only 36.6% of the participants were willing to get vaccinated every year, 70% were willing to receive a vaccine on their doctor's recommendations, and 46% agreed to vaccinate if vaccines were freely available in the university. The knowledge, barriers, and willingness widely varied across students from two disciplines. Conclusions. Our analysis underscored low flu vaccine uptake among university students. In addition, the study participants' knowledge was unsatisfactory, and they were less inclined to receive the flu vaccine in the future. Lack of recommendation from the physicians, negative perceptions towards the flu vaccine, and difficult accessibility were found as significant barriers to the vaccine uptake. A multidimensional approach at educational institutes to cover the knowledge gap and address the barriers curtailing the vaccination rate among students is recommended.
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| 25. |
- Salman, Muhammad, et al.
(författare)
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Evaluation of Conspiracy Beliefs, Vaccine Hesitancy, and Willingness to Pay towards COVID-19 Vaccines in Six Countries from Asian and African Regions : A Large Multinational Analysis
- 2022
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Ingår i: Vaccines. - : MDPI. - 2076-393X. ; 10:11
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Tidskriftsartikel (refereegranskat)abstract
- Vaccination protects people from serious illness and associated complications. Conspiracy theories and misinformation on vaccines have been rampant during the COVID-19 pandemic and are considered significant drivers of vaccine hesitancy. Since vaccine hesitancy can undermine efforts to immunize the population against COVID-19 and interferes with the vaccination rate, this study aimed to ascertain the COVID-19-vaccine-related conspiracy beliefs, vaccine hesitancy, views regarding vaccine mandates, and willingness to pay for vaccines among the general population. A web-based, cross-sectional survey was conducted (April-August 2021) among the adult population in six countries (Pakistan, Saudi Arabia, India, Malaysia, Sudan, and Egypt). Participants were recruited using an exponential, non-discriminate snowball sampling method. A validated self-completed electronic questionnaire was used for the data collection. All the participants responded to questions on various domains of the study instrument, including conspiracy beliefs, vaccine hesitancy, and willingness to pay. The responses were scored according to predefined criteria and stratified into various groups. All data were entered and analyzed using SPSS version 22. A total of 2481 responses were included in the study (Pakistan 24.1%, Saudi Arabia 19.5%, India 11.6%, Malaysia 8.1%, Sudan 19.3%, and Egypt 17.3%). There was a preponderance of participants <= 40 years old (18-25 years: 55.8%, 26-40 years: 28.5%) and females (57.1%). The average score of the COVID-19 vaccine conspiracy belief scale (C19V-CBS) was 2.30 +/- 2.12 (median 2; range 0-7). Our analysis showed that 30% of the respondents were found to achieve the ideal score of zero, indicating no conspiracy belief. The mean score of the COVID-19 vaccine hesitancy scale (C19V-HS) was 25.93 +/- 8.11 (range: 10-50). The majority (45.7%) had C19V-HA scores of 21-30 and nearly 28% achieved a score greater than 30, indicating a higher degree of hesitancy. There was a significant positive correlation between conspiracy beliefs and vaccine hesitancy (Spearman's rho = 0.547, p < 0.001). Half of the study population were against the vaccine mandate. Respondents in favor of governmental enforcement of COVID-19 vaccines had significantly (p < 0.001) lower scores on the C19V-CBS and C19V-HS scale. Nearly 52% reported that they would only take vaccine if it were free, and only 24% were willing to pay for COVID-19 vaccines. A high prevalence of conspiracy beliefs and vaccine hesitancy was observed in the targeted countries. Our findings highlight the dire need for aggressive measures to counter the conspiracy beliefs and factors underlying this vaccine hesitancy.
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