Use of the microalga Scenedesmus obliquus to remove cadmium cations from aqueous solutions

The ability of a wild strain of Scenedesmus obliquus, isolated from a heavy metal-contaminated environment, to remove Cd2+ from aqueous solutions was studied at several initial concentrations. Viable biomass removed metal to a maximum extent of 11.4 mgCd/g at 1 mgCd/l, with most Cd2+ being adsorbed onto the cell surface. A commercially available strain (ACOI 598) of the same microalga species was also exposed to the same Cd concentrations, and similar results were obtained for the maximum extent of metal removal. Heat-inactivated cells removed a maximum of 6.04 mgCd/g at 0.5 mgCd/l. The highest extent of metal removal, analyzed at various pH values, was 0.09 mgCd/g at pH 7.0. Both strains of the microalga tested have proven effective in removing a toxic heavy metal from aqueous solutions, hence supporting their choice for bioremediation strategies of industrial effluents.info:eu-repo/semantics/acceptedVersio

Computational Identification and Analysis of the Key Biosorbent Characteristics for the Biosorption Process of Reactive Black 5 onto Fungal Biomass

The performances of nine biosorbents derived from dead fungal biomass were investigated for their ability to remove Reactive Black 5 from aqueous solution. The biosorption data for removal of Reactive Black 5 were readily modeled using the Langmuir adsorption isotherm. Kinetic analysis based on both pseudo-second-order and Weber-Morris models indicated intraparticle diffusion was the rate limiting step for biosorption of Reactive Black 5 on to the biosorbents. Sorption capacities of the biosorbents were not correlated with the initial biosorption rates. Sensitivity analysis of the factors affecting biosorption examined by an artificial neural network model showed that pH was the most important parameter, explaining 22%, followed by nitrogen content of biosorbents (16%), initial dye concentration (15%) and carbon content of biosorbents (10%). The biosorption capacities were not proportional to surface areas of the sorbents, but were instead influenced by their chemical element composition. The main functional groups contributing to dye sorption were amine, carboxylic, and alcohol moieties. The data further suggest that differences in carbon and nitrogen contents of biosorbents may be used as a selection index for identifying effective biosorbents from dead fungal biomass

Kinetic, Isotherm and Thermodynamic Analysis on Adsorption of Cr(VI) Ions from Aqueous Solutions by Synthesis and Characterization of Magnetic-Poly(divinylbenzene-vinylimidazole) Microbeads

The magnetic-poly(divinylbenzene-1-vinylimidazole) [m-poly(DVB-VIM)] microbeads (average diameter 53–212 μm) were synthesized and characterized; their use as adsorbent in removal of Cr(VI) ions from aqueous solutions was investigated. The m-poly(DVB-VIM) microbeads were prepared by copolymerizing of divinylbenzene (DVB) with 1-vinylimidazole (VIM). The m-poly(DVB-VIM) microbeads were characterized by N2 adsorption/desorption isotherms, ESR, elemental analysis, scanning electron microscope (SEM) and swelling studies. At fixed solid/solution ratio the various factors affecting adsorption of Cr(VI) ions from aqueous solutions such as pH, initial concentration, contact time and temperature were analyzed. Langmuir, Freundlich and Dubinin–Radushkvich isotherms were used as the model adsorption equilibrium data. Langmuir isotherm model was the most adequate. The pseudo-first-order, pseudo-second-order, Ritch-second-order and intraparticle diffusion models were used to describe the adsorption kinetics. The apparent activation energy was found to be 5.024 kJ mol−1, which is characteristic of a chemically controlled reaction. The experimental data fitted to pseudo-second-order kinetic. The study of temperature effect was quantified by calculating various thermodynamic parameters such as Gibbs free energy, enthalpy and entropy changes. The thermodynamic parameters obtained indicated the endothermic nature of adsorption of Cr(VI) ions. Morever, after the use in adsorption, the m-poly(DVB-VIM) microbeads with paramagnetic property were separeted via the applied magnetic force. The magnetic beads could be desorbed up to about 97% by treating with 1.0 M NaOH. These features make the m-poly(DVB-VIM) microbeads a potential candidate for support of Cr(VI) ions removal under magnetic field

Prevalence of Frailty in European Emergency Departments (FEED): an international flash mob study

Introduction Current emergency care systems are not optimized to respond to multiple and complex problems associated with frailty. Services may require reconfiguration to effectively deliver comprehensive frailty care, yet its prevalence and variation are poorly understood. This study primarily determined the prevalence of frailty among older people attending emergency care. Methods This cross-sectional study used a flash mob approach to collect observational European emergency care data over a 24-h period (04 July 2023). Sites were identified through the European Task Force for Geriatric Emergency Medicine collaboration and social media. Data were collected for all individuals aged 65 + who attended emergency care, and for all adults aged 18 + at a subset of sites. Variables included demographics, Clinical Frailty Scale (CFS), vital signs, and disposition. European and national frailty prevalence was determined with proportions with each CFS level and with dichotomized CFS 5 + (mild or more severe frailty). Results Sixty-two sites in fourteen European countries recruited five thousand seven hundred eighty-five individuals. 40% of 3479 older people had at least mild frailty, with countries ranging from 26 to 51%. They had median age 77 (IQR, 13) years and 53% were female. Across 22 sites observing all adult attenders, older people living with frailty comprised 14%. Conclusion 40% of older people using European emergency care had CFS 5 + . Frailty prevalence varied widely among European care systems. These differences likely reflected entrance selection and provide windows of opportunity for system configuration and workforce planning

Klinik Örneklerden izole Edilen Trimetoprim-Sülfametoksazole Dirençli Stenotrophomonas maltophilia Suşlarinda ntegron, sul 1-2 ve dfr Genlerinin Araştirilmasi

PubMed: 24819258Stenotrophomonas maltophilia, which is a non-fermentative gram-negative bacillus, has an increasing importance in nosocomial and opportunistic infections. Since it exhibits resistance to numerous broad-spectrum antibiotics such as aminoglycosides, beta-lactams and tetracyclines, it may considerably limit empirical treatment options. Trimethoprim-sulfamethoxazole (SXT) is recommended as the first-line therapy in the treatment of S.maltophilia infections thanks to its high potency and usefulness in a range of patients. In recent years, however, studies In different geographical regions have started to report resistance to SXT. In this study, we aimed to investigate the genes sul1, sul2, dfrA9, dfrA10, dfrA20 and class I, class II integran gene cassettes which are known to play role In SXT resistance among SXT-resistant S.maltophilia strains. A total of 618 S.maltophilia strains isolated from various clinical samples of 339 patients between January 2006 and October 2011 at the laboratory of Medical Microbiology Department, Faculty of Medicine, Karadeniz Technical University, Trabzon, Turkey, were included in the study. The isolates were identified by both conventional methods and the Phoenix automated identification system (Becton Dickinson, USA). SXT resistance was determined in the isolates of 32 patients (32/339, 9.4%) by both the automated system and agar dilution method of them 29 (90.6%) were hospital-acquired, and 3 (9.4%) were community-acquired. The genes which are known as SXT resistance determining genes including sul1, sul2, dfr genes, and class I and class II integran gene cassettes were analyzed by using specific primers with polymerase chain reaction in the 32 SXT-resistant isolates. Subsequently, nucleotide sequence analysis of the amplified materials was performed. As a result of this assay, the presence of class I integran gene cassette and sul1 gene were detected in one isolate. Nucleotide sequence analysis of the gene cassette revealed oxacilinase (oxo2) type of beta-lactamase, an aminoglycoside 6'-N-acetyltransferase [aac(6')-llc], leading to resistance of aminoglycosides, and a quaternary ammonium compounds resistance gene (gocF), respectively. In conclusion, to best of our knowledge the sequences of class I integran gene cassette including oxa2, aac(6')-llc, gocF genes were identified in S.maltophilia for the first time. It should be kept in mind that the co-presence of a class I integran gene cassette and the sul1 gene in S.maltophilia may lead to the development of multi-drug resistance and may act as a potential source for the dissemination of resistance