42 research outputs found

    Forced degradation of gliquidone and development of validated stability-indicating HPLC and TLC methods

    Get PDF
    Forced degradation studies of gliquidone were conducted under different stress conditions. Three degradates were observed upon using HPLC and TLC and elucidated by LC-MS and IR. HPLC method was performed on C18 column using methanol-water (85:15 v/v) pH 3.5 as a mobile phase with isocratic mode at 1 mL.min-1 and detection at 225 nm. HPLC analysis was applied in range of 0.5-20 µg.mL-1 (r =1) with limit of detection (LOD) 0.177 µg.mL-1. TLC method was based on the separation of gliquidone from degradation products on silica gel TLC F254 plates using chloroform-cyclohexaneglacial acetic acid (6:3:1v/v) as a developing system with relative retardation 1.15±0.01. Densitometric measurements were achieved in range of 2 -20 µg /band at 254 nm (r = 0.9999) with LOD of 0.26 µg /band. Least squares regression analysis was applied to provide mathematical estimates of the degree of linearity. The analysis revealed a linear calibration for HPLC where a binomial relationship for TLC. Stability testing and methods validation have been evaluated according to International Conference on Harmonization guidelines. Moreover, the proposed methods were applied for the analysis of tablets and the results obtained were statistically compared with those of pharmacopeial method revealing no significant difference about accuracy and precision

    Controlled Noncontact Manipulation of Nonmagnetic Untethered Microbeads Orbiting Two-Tailed Soft Microrobot

    Get PDF
    A rotating two-tailed soft microrobot induces a frequency dependent flow-field in low Reynolds number fluids. We use this flow-field to achieve noncontact manipulation of nonmagnetic microbeads with average diameter of 30 μ m in 2-D space. Our noncontact manipulation strategy capitalizes on exerting a rotational magnetic torque on the magnetic dipole of the microrobot. The induced flow-field enables microbeads in the surrounding fluid to orbit the microrobot along a sprocketlike trajectory due to a periodic and asymmetric flow-field caused by the two tails. A hydrodynamic model of the two-tailed microrobot and the orbiting microbeads is developed based on the method of regularized Stokeslets for computing Stokes flows. The relations between the angular velocity of the orbiting microbeads and the rotation frequency of the microrobot, their proximity (p), and tail length ratio of the microrobots are studied theoretically and experimentally. Our simulations and experimental results show that the angular velocity of the orbiting microbeads decreases nearly as |p|-2 with the distance to the microrobot and its tail length ratio. We also demonstrate closed-loop control of the microbeads toward target positions along sprocketlike trajectories with an average position error of 23.1 ± 9.1 μ m (n=10), and show the ability to swim away without affecting the positioning accuracy after manipulation

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

    Get PDF
    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

    Get PDF
    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

    Influence of TiB2 particles on the solidification behaviour of aluminium alloys

    No full text
    EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Los iconos coptos de Egipto

    Get PDF
    La tesis pretende aportar a la historia del arte nuevos conocimientos acerca del icono egipcio, que faciliten y promuevan su conservación y restauración artística, tanto en España como en Egipto

    Semantic risk assessment for ad hoc and amended standard forms of construction contracts

    No full text
    In spite of the widespread availability and documented advantages of using standard forms of construction contracts (SFCs), actual practice and recent evidence suggest that owners still rely on ad hoc (bespoke) or heavily amended SFCs. This practice is problematic to contractors who are required to submit tenders within tight time frames and hastily assess the risk allocation of these nonstandard forms of contract. This paper presents a semantic model and quantitative assessment framework to help assess the risk allocation of these contracts and hence allow more informed decisions to be made by contractors prior to tender submission. The model is based on 9 clause families and 41 construction clause components that were determined based on a detailed analysis of 4 major SFCs as well as several bespoke and heavily amended SFCs, in addition to a subsequent verification by domain experts. The analytical hierarchy process (AHP) is further used to assign relative weights to the clause families and components based on collaborative input from 10 construction contract experts. The model was tested on two case studies for a residential construction and hotel retrofit projects. Results show that the contract risk rating (CRR) computed by the model closely correlates to the contingency values allocated by contractors into their tender price
    corecore