1,449 research outputs found

    Iron(III)-catalyzed chlorination of activated arenes

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    A general and regioselective method for the chlorination of activated arenes has been developed. The transformation uses iron(III) triflimide as a powerful Lewis acid for the activation of N-chlorosuccinimide and the subsequent chlorination of a wide range of anisole, aniline, acetanilide and phenol derivatives. The reaction was utilized for the late-stage mono- and di-chlorination of a range of target compounds such as the natural product nitrofungin, the antibacterial agent chloroxylenol and the herbicide chloroxynil. The facile nature of this transformation was demonstrated with the development of one-pot tandem iron-catalyzed dihalogenation processes allowing highly regioselective formation of different carbon-halogen bonds. The synthetic utility of the resulting dihalogenated aryl compounds as building blocks was established with the synthesis of natural products and pharmaceutically relevant targets

    Monitoring and Assessing the Coastal Ecosystem at Hurghada, Red Sea Coast, Egypt

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    In the framework of the investment plan, the government of Egypt introduced an accelerated development of Hurghada in collaboration with the private sector, as   early as 1980's.  The government intended to construct tourist resort communities, which required establishment of infrastructures. The  demand  of  such  facilities, in absence of enforced environmental roles led owners  to implement  processes  of  landfilling  and  dredging  for the purpose of smoothing, paving and widening the beach in order to construct swimming pools, marinas and other recreational facilities. Such activities came on the expense of the marine ecosystem and especially assault on the coral reef communities. For monitoring and assessing such oppressive activities;  MSS,  TM,  ETM+,  and SPOT XS 4 satellite images acquired  during  1972,  1984,  1992,  2004  and 2011. Shoreline change detection from 1972 to 2011 reveals landfilling of some 7.56Km2 and dredging of 2.67km2, with loss of 5.34km2 of the reef tracts. At the same period, the region has witnessed expansions in urban and road network by 16.47km2 and 8.738km2 respectively. The Egyptian government issued the essential laws for regulating and saving the coastal ecosystem, yet mostly violated. Activation of such laws, applying judicial officers, toughening penalties and establishment of coastal building front line (CBFL), and a reef protection line (RPL) are important tasks especially south of Hurghada to the Egyptian-Sudanese borders to preserve the remnants of such unique coastal ecosystem. Keywords: Satellite images, Hurghada, Red Sea, coastal ecosystem, shoreline changes, urban, road network, environment law

    Development of new thiazolidine-2,4-dione hybrids as aldose reductase inhibitors endowed with antihyperglycaemic activity: design, synthesis, biological investigations, and in silico insights

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    This research study describes the development of new small molecules based on 2,4-thiazolidinedione (2,4-TZD) and their aldose reductase (AR) inhibitory activities. The synthesis of 17 new derivatives of 2,4-TZDs hybrids was feasible by incorporating two known bioactive scaffolds, benzothiazole heterocycle, and nitro phenacyl moiety. The most active hybrid (8b) was found to inhibit AR in a non-competitive manner (0.16 µM), as confirmed by kinetic studies and molecular docking simulations. Furthermore, the in vivo experiments demonstrated that compound 8b had a significant hypoglycaemic effect in mice with hyperglycaemia induced by streptozotocin. Fifty milligrams per kilogram dose of 8b produced a marked decrease in blood glucose concentration, and a lower dose of 5 mg/kg demonstrated a noticeable antihyperglycaemic effect. These outcomes suggested that compound 8b may be used as a promising therapeutic agent for the treatment of diabetic complications

    A validated stability-indicating HPLC method for determination of varenicline in its bulk and tablets

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    A simple, sensitive and accurate stability-indicating HPLC method has been developed and validated for determination of varenicline (VRC) in its bulk form and pharmaceutical tablets. Chromatographic separation was achieved on a Zorbax Eclipse XDB-C8 column (150 mm × 4.6 mm i.d., particle size 5 μm, maintained at ambient temperature) by a mobile phase consisted of acetonitrile and 50 mM potassium dihydrogen phosphate buffer (10:90, v/v) with apparent pH of 3.5 ± 0.1 and a flow rate of 1.0 ml/min. The detection wavelength was set at 235 nm. VRC was subjected to different accelerated stress conditions. The degradation products, when any, were well resolved from the pure drug with significantly different retention time values. The method was linear (r = 0.9998) at a concentration range of 2 - 14 μg/ml. The limit of detection and limit of quantitation were 0.38 and 1.11 μg/ml, respectively. The intra- and inter-assay precisions were satisfactory; the relative standard deviations did not exceed 2%. The accuracy of the method was proved; the mean recovery of VRC was 100.10 ± 1.08%. The proposed method has high throughput as the analysis involved short run-time (~ 6 min). The method met the ICH/FDA regulatory requirements. The proposed method was successfully applied for the determination of VRC in bulk and tablets with acceptable accuracy and precisions; the label claim percentages were 99.65 ± 0.32%. The results demonstrated that the method would have a great value when applied in quality control and stability studies for VRC

    Design, synthesis, and biological investigation of oxadiazolyl, thiadiazolyl, and pyrimidinyl linked antipyrine derivatives as potential non-acidic anti-inflammatory agents

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    A novel series of 12 antipyrine derivatives containing 1,3,4-oxadiazoles (4a-d), 1,3,4-thiadiazoles (6a-d), and pyrimidines (8a-d), was preparedand assessed for its potential in vitro COX-2 inhibitors. Compared to Celecoxib, compounds 4b-d and 8d were the most potent derivatives c with a half-maximal inhibitory concentration range of 53-69 nM. Considering COX-2 selectivity index, compounds 4 b and 4c were chosen among these most potent derivatives for further investigation. The in vivo ability of compounds 4 b and 4c to counteract carrageenan-induced paw edoema has been assessed and their potential underlying mechanisms have been elucidated and the results have been further validated using molecular docking simulations

    Formulation and evaluation of orally disintegrating clopidogrel tablets

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    ABSTRACT Recent advances in drug delivery systems have aimed to achieve better patient compliance. One of these advances is the formulation of orally disintegrating tablets (ODTs) that dissolve instantaneously, releasing drugs within a few seconds without the need of water. The main objective of this paper was to prepare and develop ODTs of clopidogrel. The ODTs were prepared by direct compression. The effect of three superdisintegrants, namely crospovidone, croscarmellose sodium, and sodium starch glycolate, using three different disintegration times on the dissolution rate was investigated. The prepared tablets were evaluated for hardness, friability, disintegration time and in vitro drug release. Furthermore, the interaction of clopidogrel with the formulation excipients was studied using differential scanning calorimetry (DSC). DSC studies revealed that there were no interactions between the drug and the excipients used. All tablets had hardness values in the range 4.0-5.2 kp and friability lower than 1%. The weight and drug content uniformity of all formulations was within official limits according to BP. In vitro drug release studies of the ODTs showed that more than 90% of the drug was released within ten minutes. A palatability test in human volunteers showed acceptable taste and mouth feel. Thus, the obtained results conclusively demonstrated successful rapid disintegration of the formulated tablets and acceptable palatability

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

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    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

    Global, regional, and national burden of chronic kidney disease, 1990–2017 : a systematic analysis for the Global Burden of Disease Study 2017

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    Background Health system planning requires careful assessment of chronic kidney disease (CKD) epidemiology, but data for morbidity and mortality of this disease are scarce or non-existent in many countries. We estimated the global, regional, and national burden of CKD, as well as the burden of cardiovascular disease and gout attributable to impaired kidney function, for the Global Burden of Diseases, Injuries, and Risk Factors Study 2017. We use the term CKD to refer to the morbidity and mortality that can be directly attributed to all stages of CKD, and we use the term impaired kidney function to refer to the additional risk of CKD from cardiovascular disease and gout. Methods The main data sources we used were published literature, vital registration systems, end-stage kidney disease registries, and household surveys. Estimates of CKD burden were produced using a Cause of Death Ensemble model and a Bayesian meta-regression analytical tool, and included incidence, prevalence, years lived with disability, mortality, years of life lost, and disability-adjusted life-years (DALYs). A comparative risk assessment approach was used to estimate the proportion of cardiovascular diseases and gout burden attributable to impaired kidney function. Findings Globally, in 2017, 1·2 million (95% uncertainty interval [UI] 1·2 to 1·3) people died from CKD. The global all-age mortality rate from CKD increased 41·5% (95% UI 35·2 to 46·5) between 1990 and 2017, although there was no significant change in the age-standardised mortality rate (2·8%, −1·5 to 6·3). In 2017, 697·5 million (95% UI 649·2 to 752·0) cases of all-stage CKD were recorded, for a global prevalence of 9·1% (8·5 to 9·8). The global all-age prevalence of CKD increased 29·3% (95% UI 26·4 to 32·6) since 1990, whereas the age-standardised prevalence remained stable (1·2%, −1·1 to 3·5). CKD resulted in 35·8 million (95% UI 33·7 to 38·0) DALYs in 2017, with diabetic nephropathy accounting for almost a third of DALYs. Most of the burden of CKD was concentrated in the three lowest quintiles of Socio-demographic Index (SDI). In several regions, particularly Oceania, sub-Saharan Africa, and Latin America, the burden of CKD was much higher than expected for the level of development, whereas the disease burden in western, eastern, and central sub-Saharan Africa, east Asia, south Asia, central and eastern Europe, Australasia, and western Europe was lower than expected. 1·4 million (95% UI 1·2 to 1·6) cardiovascular disease-related deaths and 25·3 million (22·2 to 28·9) cardiovascular disease DALYs were attributable to impaired kidney function. Interpretation Kidney disease has a major effect on global health, both as a direct cause of global morbidity and mortality and as an important risk factor for cardiovascular disease. CKD is largely preventable and treatable and deserves greater attention in global health policy decision making, particularly in locations with low and middle SDI
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