12 research outputs found

    Effect of Interaction between Bridge Piers on Local Scouring in Cohesive Soils

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    Local scour at the piers is one of the main reasons of bridge foundation undermining. Earlier research studies focused mainly on the scour at a single bridge pier; nevertheless, modern designs of the bridges comprise wide-span and thus group of piers rather than a single pier are usually used to support the superstructure. The flow and scour pattern around group of piers is different from the case of a single pier due to the interaction effect. Reviewing the literature of local scour around bridge piers group revealed that the local scour around bridge piers group founded in cohesive soil bed was not investigated, and most of the scour studies were related to scour in cohesionless soils. The objective of the present study is to investigate the effect of the interaction between two in-line (tandem) circular bridge piers of variable spacings founded in cohesive soil on the local scour. A set of laboratory flume experiments were conducted under the clear-water scour condition to investigate this effect. This study is the first that investigates experimentally the scour around group of bridge piers in cohesive bed. It was found that the maximum scour depth at the upstream pier of the two in-line piers occurred at a spacing of two times the diameter of the pier, scour at the downstream pier was reduced due to a sheltering effect, the interference effect will be reduced for pier spacings larger than three times of the pier diameter. A recent pier scour equation was used to estimate the scour depths at the two in-line piers in cohesive soil and compare the estimated value with the measured scour depths in the laboratory. The comparison indicated that the proposed scour equation overestimates the scour depths at both the upstream and the downstream pier

    2D-HEC-RAS Modeling of Flood Wave Propagation in a Semi-Arid Area Due to Dam Overtopping Failure

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    Dam overtopping failure and the resulting floods are hazardous events that highly impact the inundated areas and are less predictable. The simulation of the dam breach failure and the flood wave propagation is necessary for assessing flood hazards to provide precautions. In the present study, a two-dimensional HEC-RAS model was used to simulate the flood wave resulting from the hypothetical failure of Al-Udhaim Dam on Al-Udhaim River, Iraq, and the propagation of the resulting dam-break wave along 100 km downstream the dam site for the overtopping scenario. The main objective is to analyze the propagation of the flood wave so that the failure risk on dam downstream areas can be assessed and emergency plans may be provided. The methodology consisted of two sub-models: the first is the dam breach failure model for deriving the breach hydrograph, and the second is the hydrodynamic model for propagating the flood wave downstream of the dam. The breach hydrograph is used as an upstream boundary condition to derive the flood impact in the downstream reach of Al- Udhaim River. The flood inundation maps were visualized in RAS-Mapper in terms of water surface elevation, water depth, flow velocity, and flood arrival time. The maximum recorded values were: 105 m (a.m.s.l.), 18 m, 5.5 m/s, and, respectively. The flow velocity decreased from upstream to downstream of the terrain, which means less risk of erosion in the far reaches downstream of the study area. The inundation maps indicated that the water depth and flow velocity were categorized as Catastrophic limits on the terrain's area. The results offer a way to predict flood extent and showed that the impact of a potential dam break at Al-Udhiam Dam will be serious, therefore, suitable management is needed to overcome this risk. Moreover, the maps produced by this study are useful for developing plans for sustainable flood management. Doi: 10.28991/cej-2021-03091739 Full Text: PD

    Evaluation of the protective effect of Omega-7 against Methotrexate Genotoxicity in bone marrow Cells of Mice

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    Background: A substance that can affect DNA or chromosomes is defined as a genotoxin. DNA damage in a somatic cell may result in a somatic mutation (cancer). In contrast, damage to a germ cell (germline mutation) may result in a heritable changed characteristic.Omega-7 is a non-essential monounsaturated free fatty acid with anti-inflammatory, anti-obesity, and antidiabetic effects. Objectives: Evaluation of the possible protective effects of omega seven against methotrexate genotoxicity. Method: Two major equal groups were obtained from seventy mice, and five subgroups (each of seven) were created from these groups as follows: Group I received liquid paraffin orally for seven successive days. Group II: received liquid paraffin orally for seven successive days, followed by a single intraperitoneal dose of methotrexate (20 mg/kg) on the eighth day. Group III: received omega-7 (50mg/kg) orally for seven successive days, followed by a single intraperitoneal dose of methotrexate (20 mg/kg) on the eighth day. Group IV: received omega-7 (100mg/kg) orally for seven successive days, followed by a single intraperitoneal dose of methotrexate (20 mg/kg) on the eighth day. Group V: received omega-7 (100mg/kg) orally for seven successive days. The first major group was intraperitoneally injected with 1mg/kg colchicine, and then after two hours, all mice were killed by spinal dislocation. Bone marrow cells from the first major group were used to measure the mitotic index and chromosomal aberrations, and bone marrow cell of the second group was used to measure the appearance of the micronucleus. Statistical Package for Social Sciences (SPSS) and ANOVA test were used to compare groups. Results: Treatment of mice with omega-7 led to a significant decline in chromosomal aberration and micronucleus aberrance with a significant elevation of the mitotic index. Conclusion: Omega-7 has been shown to have a protective role against methotrexate genotoxicity. Received: April, 2023 Accepted: July, 2023 Published: Jan.202

    An Overview of Differences Between Types of Chimeras and Their Impact on Humans

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    Chimera has several important definitions that are common to each other, where he is known a single creature that is made up of two or more separate populations of genetically unique cells that originated from various zygotes. Definition can be interpreted as cells from one person might appear in another individual in a process known as chimerism. These cells may be incorporated into the parenchyma or they may circulate. Chimeras are divided into several types depending on several factors such as the percentage of chimera cells in the body of the organism neighborhood, origin, or other reasons, which includes microchimeras, natural human macro-chimeras and man-made chimeras. Chimeric cells in human can arise from three significant sources, namely originating from gestation, blood transfusions, and transplants

    Endoscopic third ventriculostomy for obstructive hydrocephalus

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    Introduction: Obstructive hydrocephalus has long been managed by valve-regulated shunts. These shunts are associated with a myriad of short and long-term complications. This has fueled interest in Endoscopic Third Ventriculostomy (ETV) which provides a more physiological pathway for cerebrospinal fluid (CSF) diversion while avoiding many shunt-related complications. Aim: The objective of this study is to analyze the outcomes of ETV at our institution, focusing on the indications, success rates, and short-term complications. Methods: Between July 2010 and September 2015, 47 patients with obstructive hydrocephalus underwent ETV at the Neurosurgery Teaching Hospital in Baghdad/ Iraq. We retrospectively analyzed the data of these patients using hospital health records. Simple statistics were performed using  SPSS Version 20. A standardized surgical technique was employed in all cases. Results: The mean age was 4.4 years (range 40 days - 38 years). The male: female ratio was 1.23:1 (55% males and 45% females). The most common cause of obstructive hydrocephalus in patients undergoing ETV was aqueductal stenosis (62%; N=29). The second most common cause was posterior fossa tumours (23%; N=11). The overall success rate for ETV was 68%. The net post-operative complication rate was 13% (N=6). CSF leak and seizures were the only two charted post-operative complications at the rates of 9%(N=4) and 4% (N=2), accordingly. No deaths were recorded. Conclusion: ETV is a viable alternative to shunt insertion in a select group of patients with obstructive hydrocephalus, with acceptable success rate and safety profile

    TiO2/PEG as smart anticorrosion and drug-eluting platforms in inflammatory conditions

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    The failure of a titanium implant is often attributed to inflammatory reactions following implantation. This study focuses on the synthesis of a polyethylene glycol (PEG) layer on porous titanium dioxide (TiO2) coatings using plasma electrolytic oxidation (PEO). This PEG layer serves as a foundation for a drug-eluting platform designed to respond to pH stimuli during inflammation. Betamethasone (BET), a widely used anti-inflammatory drug, was loaded onto the pH-responsive functional PEG layers. The application of the PEG-BET layer onto TiO2 coatings through the vacuum dip coating method resulted in a pH-sensitive sustained release of BET over a 30-day period. Notably, the release rates were 81% at pH 5.0 and 55% at pH 7.2. Electrochemical corrosion tests conducted in both normal and acidic inflammatory solutions demonstrated that duplex composite coatings offer superior protection compared to simple oxide coatings. In a pH 5.0 solution, corrosion current density measurements revealed values of 1.75 μA cm−2 (PEO/PEG-BET), 8.87 μA cm−2 (PEO), and 49.17 μA cm−2 (bare titanium). These results highlight the effectiveness of the PEO/PEG-BET layer in sealing pores within PEO coatings, subsequently reducing the infiltration of corrosive ions in inflammatory environments

    Hospital admission trends due to respiratory diseases in England and Wales between 1999 and 2019: an ecologic study

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    BACKGROUND: Identifying trends of hospital admissions for respiratory diseases is crucial for public health and research to guide future clinical improvements for better outcomes. This study aims to define the trends of respiratory disease-related hospital admissions (RRHA) in England and Wales between 1999 and 2019. METHODS: An ecological study was conducted using hospital admission data taken from the Hospital Episode Statistics database in England and the Patient Episode Database for Wales. Hospital admissions data for respiratory diseases were extracted for the period between April 1999 and March 2019. The trend in hospital admissions was assessed using a Poisson model. RESULTS: Hospital admission rate increased by 104.7% [from 1535.05 (95% CI 1531.71–1538.38) in 1999 to 3142.83 (95% CI 3138.39–3147.26) in 2019 per 100,000 persons, trend test, p < 0.01]. The most common causes were influenza and pneumonia, chronic lower respiratory diseases, other acute lower respiratory infections, which accounted for 26.6%, 26.4%, and 14.9%, respectively. The age group 75 years and above accounted for 34.1% of the total number of hospital admissions. Males contributed to 50.5% of the total number of hospital admissions. Hospital admission rate in females increased by 119.8% [from 1442.18 (95% CI 1437.66–1446.70) in 1999 to 3169.38 (95% CI 3163.11–3175.64) in 2019 per 100,000 persons, trend test, p < 0.001]. Hospital admission rate increased by 92.9% in males [from 1633.25 (95% CI 1628.32–1638.17) in 1999 to 3149.78 (95% CI 3143.46–3156.09) in 2019 per 100,000 persons, trend test, p < 0.001]. CONCLUSION: During the study period, hospital admissions rate due to respiratory diseases increased sharply. The rates of hospital admissions were higher among males for the vast majority of respiratory diseases. Further observational studies are warranted to identify risk factors for these hospital admissions and to offer relevant interventions to mitigate the risk

    Hospital admissions due to ischemic heart diseases and prescriptions of cardiovascular diseases medications in England and Wales in the past two decades

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    Objectives: The aim of this study was to explore the trend of ischemic heart disease (IHD) admission and the prescriptions of IHD medications in England and Wales. Methods: A secular trends study was conducted during the period of 1999 to 2019. We extracted hospital admission data for patients from all age groups from the Hospital Episode Statistics database in England and the Patient Episode Database for Wales. Prescriptions of IHD medications were extracted from the Prescription Cost Analysis database from 2004 to 2019. The chi-squared test was used to assess the difference between the admission rates and the difference between IHD medication prescription rates. The trends in IHD-related hospital admission and IHD-related medication prescription were assessed using a Poisson model. The correlation between hospital admissions for IHD and its IHD medication-related prescriptions was assessed using the Pearson correlation coefficient. Results: Our study detected a significant increase in the rate of cardiovascular disease (CVD) medication prescriptions in England and Wales, representing a rise in the CVD medications prescription rate of 41.8% (from 539,334.95 (95% CI = 539,286.30–539,383.59) in 2004 to 764,584.55 (95% CI = 764,545.55–764,623.56) in 2019 prescriptions per 100,000 persons), with a mean increase of 2.8% per year during the past 15 years. This increase was connected with a reduction in the IHD hospital admission rate by 15.4% (from 838.50 (95% CI = 836.05–840.94) in 2004 to 709.78 (95% CI = 707.65–711.92) in 2019 per 100,000 persons, trend test, p < 0.01), with a mean decrease of 1.02% per year during the past 15 years and by 5% (from 747.43 (95% CI = 745.09–749.77) in 1999 to 709.78 (95% CI = 707.65–711.92) in 2019 per 100,000 persons, trend test, p < 0.01) with a mean decrease of 0.25% per year during the past two decades in England and Wales. Conclusion: The rate of hospitalisation due to IHD has decreased in England and Wales during the past two decades. Hospitalisation due to IHD was strongly and negatively correlated with the increase in the rates of dispensing of IHD-related medications. Other factors contributing to this decline could be the increase in controlling IHD risk factors during the past few years. Future studies exploring other risk factors that are associated with IHD hospitalisation are warranted
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