1,290 research outputs found

    Comprehensive calculations of three--body breakup cross sections

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    We present in detail a theoretical model for fragmentation reactions of three--body halo nuclei. The different reaction mechanisms corresponding to the different processes are described and discussed. Coulomb and nuclear interactions are simultaneously included and the method is therefore applicable for any target, light, intermediate and heavy. Absolute values of many differential cross sections are then available as function of beam energy and target. We apply the method to fragmentation of 6^6He and 11^{11}Li on C, Cu and Pb. A large variety of observables, cross sections and momentum distributions, are computed. In almost all cases we obtain good agreement with the available experimental data.Comment: 41 pages, 10 figures, to be published in Nucl. Phys.

    Preliminary Investigation of the Corrosion Behavior of Proprietary Micro-alloyed Steels in Aerated and Deaerated Brine Solutions

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    The corrosion performance of fairly new generation of micro-alloyed steels was compared in different concentrations of aerated and deaerated brines. Electrochemical polarization, weight loss and surface analyses techniques were employed. The results showed a threshold of corrosion rate at 3.5 wt.% NaCl in both aerated and deaerated solutions. The average corrosion current density for steel B, for example, increased from 1.3 µA cm¯² in 1 wt.% NaCl to 1.5 µA cm¯² in 3.5 wt.% NaCl, but decreased to 1.4 µA cm¯² in 10 wt.% deaerated NaCl solutions. The aerated solutions exhibited an average of over 80% increase in corrosion current density in the respective concentrations when compared with the deaerated solution. These results can be attributed to the effects of dissolved oxygen (DO) which has a maximum solubility in 3.5 wt.% NaCl. DO as a depolarizer and electron acceptor in cathodic reactions accelerates anodic metal dissolution. The difference in carbon content and microstructures occasioned by thermo-mechanical treatment contributed to the witnessed variation in corrosion performance of the steels. Specifically, the results of the various corrosion techniques corroborated each other and showed that the corrosion rate of the micro-alloyed steels can be ranked as CR[Steel A] < CRₓ₆₅ < CR[Steel B] < CR[Steel C]

    Berberine-Induced Amelioration of the Pathological Changes in Nutrient&apos;s Homeostasis During Murine Intestinal Eimeria papillata Infection

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    Abstract.-The current work aimed to study the ameliorative effect of berberine on the induced pathological changes in nutrient&apos;s homeostasis in mice infected with Eimeria papillata. Mice were randomly divided into three groups. The first group represents the control non-infected animals. Second and third groups were orally infected with 1.5×10 3 sporulated E. papillata oocysts. The 3 rd group was treated with a daily dose (10 mg/kg) of berberine chloride solution for five successive days. All animals were sacrificed on day 5 p.i.. E. papillata infection induced a state of disturbance in nutrient homeostasis. Blood glucose levels and total proteins were elevated with concurrent decrease in level of carbohydrates and soluble proteins in jejunum of mice. Also, infection induced a hyperlipidemic status as shown from the increase in triglycerides, total lipids, total cholesterol, high density lipoprotein cholesterol (LDL) with the mutual decrease in high density lipoprotein cholesterol (HDL) and phospholipids. Also, E. papillata caused marked disturbance in blood metal ion concentrations. Both ferrous and selenium ion levels were decreased, while sodium and potassium ion concentrations were increased. Berberine treatment of infected mice with E. papillata showed a great enhancement in nutrient homeostatic status and also reduced blood glucose level and restored jejunal carbohydrate content. In addition, berberine exerted hypolipidemic effect on the increased fractions of carbohydrates and lipids. Finally, berberine showed a marked enhancement in the levels of altered blood metal ions by the infection. Palm pollen grains or their extracts could be used within food mixtures or water to correct the induced metabolic disturbance and growth depression associated with the intestinal coccidial infections

    Hypofibrinolysis in diabetes: a therapeutic target for the reduction of cardiovascular risk

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    An enhanced thrombotic environment and premature atherosclerosis are key factors for the increased cardiovascular risk in diabetes. The occlusive vascular thrombus, formed secondary to interactions between platelets and coagulation proteins, is composed of a skeleton of fibrin fibres with cellular elements embedded in this network. Diabetes is characterised by quantitative and qualitative changes in coagulation proteins, which collectively increase resistance to fibrinolysis, consequently augmenting thrombosis risk. Current long-term therapies to prevent arterial occlusion in diabetes are focussed on anti-platelet agents, a strategy that fails to address the contribution of coagulation proteins to the enhanced thrombotic milieu. Moreover, antiplatelet treatment is associated with bleeding complications, particularly with newer agents and more aggressive combination therapies, questioning the safety of this approach. Therefore, to safely control thrombosis risk in diabetes, an alternative approach is required with the fibrin network representing a credible therapeutic target. In the current review, we address diabetes-specific mechanistic pathways responsible for hypofibrinolysis including the role of clot structure, defects in the fibrinolytic system and increased incorporation of anti-fibrinolytic proteins into the clot. Future anti-thrombotic therapeutic options are discussed with special emphasis on the potential advantages of modulating incorporation of the anti-fibrinolytic proteins into fibrin networks. This latter approach carries theoretical advantages, including specificity for diabetes, ability to target a particular protein with a possible favourable risk of bleeding. The development of alternative treatment strategies to better control residual thrombosis risk in diabetes will help to reduce vascular events, which remain the main cause of mortality in this condition

    A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

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    On the approximations to fractional nonlinear damped Burger’s-type equations that arise in fluids and plasmas using Aboodh residual power series and Aboodh transform iteration methods

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    Damped Burger’s equation describes the characteristics of one-dimensional nonlinear shock waves in the presence of damping effects and is significant in fluid dynamics, plasma physics, and other fields. Due to the potential applications of this equation, thus the objective of this investigation is to solve and analyze the time fractional form of this equation using methods with precise efficiency, high accuracy, ease of application and calculation, and flexibility in dealing with more complicated equations, which are called the Aboodh residual power series method and the Aboodh transform iteration method (ATIM) within the Caputo operator framework. Also, this study intends to further our understanding of the dynamic characteristics of solutions to the Damped Burger’s equation and to assess the effectiveness of the proposed methods in addressing nonlinear fractional partial differential equations. The two proposed methods are highly effective mathematical techniques for studying more complicated nonlinear differential equations. They can produce precise approximate solutions for intricate evolution equations beyond the specific examined equation. In addition to the proposed methods, the fractional derivatives are processed using the Caputo operator. The Caputo operator enhances the representation of fractional derivatives by providing a more accurate portrayal of the underlying physical processes. Based on the proposed two approaches, a set of approximations to damped Burger’s equation are derived. These approximations are discussed graphically and numerically by presenting a set of two- and three-dimensional graphs. In addition, these approximations are analyzed numerically in several tables, including the absolute error for each approximate solution compared to the exact solution for the integer case. Furthermore, the effect of the fractional parameter on the behavior of the derived approximations is examined and discussed

    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

    Laparoscopy in management of appendicitis in high-, middle-, and low-income countries: a multicenter, prospective, cohort study.

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    BACKGROUND: Appendicitis is the most common abdominal surgical emergency worldwide. Differences between high- and low-income settings in the availability of laparoscopic appendectomy, alternative management choices, and outcomes are poorly described. The aim was to identify variation in surgical management and outcomes of appendicitis within low-, middle-, and high-Human Development Index (HDI) countries worldwide. METHODS: This is a multicenter, international prospective cohort study. Consecutive sampling of patients undergoing emergency appendectomy over 6 months was conducted. Follow-up lasted 30 days. RESULTS: 4546 patients from 52 countries underwent appendectomy (2499 high-, 1540 middle-, and 507 low-HDI groups). Surgical site infection (SSI) rates were higher in low-HDI (OR 2.57, 95% CI 1.33-4.99, p = 0.005) but not middle-HDI countries (OR 1.38, 95% CI 0.76-2.52, p = 0.291), compared with high-HDI countries after adjustment. A laparoscopic approach was common in high-HDI countries (1693/2499, 67.7%), but infrequent in low-HDI (41/507, 8.1%) and middle-HDI (132/1540, 8.6%) groups. After accounting for case-mix, laparoscopy was still associated with fewer overall complications (OR 0.55, 95% CI 0.42-0.71, p < 0.001) and SSIs (OR 0.22, 95% CI 0.14-0.33, p < 0.001). In propensity-score matched groups within low-/middle-HDI countries, laparoscopy was still associated with fewer overall complications (OR 0.23 95% CI 0.11-0.44) and SSI (OR 0.21 95% CI 0.09-0.45). CONCLUSION: A laparoscopic approach is associated with better outcomes and availability appears to differ by country HDI. Despite the profound clinical, operational, and financial barriers to its widespread introduction, laparoscopy could significantly improve outcomes for patients in low-resource environments. TRIAL REGISTRATION: NCT02179112

    Geigeria Alata- a Potential Source for Anti-Alzheimer’s Constituents: In Vitro and Computational Investigations

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    Antioxidants and acetylcholinesterase inhibitors play a key role in the prevention and management of degenerative disorders including Alzheimer’s disease in particular. Identifying new anticholinesterases from natural sources may contribute to combating this class of diseases. The present study aimed to evaluate the potential anti-Alzheimer’s activity of Geigeria alata (DC), a plant used in Sudanese folkloric medicine. Accordingly, the whole DC plant extract including twenty phytoconstituents of phenolic, flavonoid, and tannin types was evaluated in vitro as antioxidants and acetylcholinesterase inhibitors. As well, their pharmacokinetics, drug likeliness, and toxicity profiles were assessed. Additionally, the virtual binding of the plant’s phytoconstituents with the cholinesterase target was investigated by docking against two AChE X-ray crystallographic structures. The best effective DPPH radical scavenging activity was demonstrated by both ethyl acetate and n-butanol fractions with percentages of inhibition of 91 ± 0.02% and 90 ± 0.02% (IC50 22 ± 0.01 and 66 ± 0.02 µg/mL), respectively. The ethyl acetate fraction showed statistically significant, and the highest AChE inhibitory activity (78% inhibition, IC50 0.246 ± 0.02 mg/mL). Furthermore, the ethyl acetate fraction exhibited the highest total phenolic, flavonoid, and tannin values. Among identified compounds, quercetin and hispidulin showed promising in silico anti-AChE activity and hence merit further studies for the isolation and characterization of these active constituents. &nbsp

    Analytical solutions to time-space fractional Kuramoto-Sivashinsky Model using the integrated Bäcklund transformation and Riccati-Bernoulli sub-ODE method

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    This paper solves an example of a time-space fractional Kuramoto-Sivashinsky (KS) equation using the integrated Bäcklund transformation and the Riccati-Bernoulli sub-ODE method. A specific version of the KS equation with power nonlinearity of a given degree is examined. Using symbolic computation, we find new analytical solutions to the current problem for modeling many nonlinear phenomena that are described by this equation, like how the flame front moves back and forth, how fluids move down a vertical wall, or how chemical reactions happen in a uniform medium while they oscillate uniformly across space. In the field of mathematical physics, the Riccati-Bernoulli sub-ODE approach is shown to be a valuable tool for producing a variety of single solutions
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