Synthesis and antibacterial effects of cobalt–cellulose magnetic nanocomposites

© The Royal Society of Chemistry. Green synthesis is employed to prepare cobalt/cellulose nanocomposites with cubic (α-cobalt) cobalt as a main component with antibacterial and magnetic properties. An in situ reduction of aqueous solutions of cobalt ions on a model cellulose substrate surface using hydrogen gas affords spherical, cellulose-stabilised cobalt nanoclusters with magnetic properties and an average diameter of 7 nm that are distributed evenly over the surface of the cellulose fibres. These cobalt/cellulose nanocomposites exhibit good antibacterial action against opportunistic pathogens both Gram-positive (S. aureus) and Gram-negative (E. coli, A. baumannii and P. aeruginosa), with zones of inhibition up to 15 mm, thereby encouraging the deployment of these advanced materials for the treatment of wastewater or within medical dressings. This method of preparation is compared with the analogous in situ reduction of cobalt ions on a cellulose surface using sodium borohydride as reducing agent

A Simple Biomimetic Receptor Selectively Recognizing the GlcNAc2 Disaccharide in Water

AbstractGlcNAc2 is the core disaccharide fragment present in N‐glycans exposed on the surface of enveloped viruses of high health concern, such as coronaviruses. Because N‐glycans are directly involved in the docking of viruses to host cells, recognition of GlcNAc2 by a biomimetic receptor may be a convenient alternative to the use of lectins to interfere with viral entry and infection. Herein, we describe a simple biomimetic receptor recognizing the methyl‐β‐glycoside of GlcNAc2 in water with an unprecedented affinity of 160 μM, exceeding that of more structurally complex receptors reported in the literature. The tweezers‐shaped acyclic structure exhibits marked selectivity among structurally related disaccharides, and complete discrimination between mono‐ and disaccharides. Molecular modelling calculations supported by NOE data provided a three‐dimensional description of the binding mode, shedding light on the origin of the affinities and selectivities exhibited by the receptor

Numerical analysis of energy recovery system for turbocharged internal combustion engines via a parallel compounding turbine

Increasing energy efficiency requirements mandatory ask for optimizing energy utilization in many devices, which include internal combustion engines. One of the most investigated subjects is the energy recovery from the exhaust, such as turbo-compound systems, which usually consist in a secondary turbine located afterward the turbocharger. Here an alternative arrangement is proposed and analysed via a numerical model. The recovery turbine works in parallel to the main turbine and uses the gasses which would be otherwise wasted through the waste-gate valve, once the set-point boost pressure is reached. The reference case analysed is a 12.4L turbocharged diesel engine, commonly used in marine, road and light railroad applications, with a nominal power of 380kW. The results showed that an overall 8% of power can be gained, without nor increasing the fuel mass flow rate, neither requiring significant modifications to the baseline engine. Moreover, in the case of the recovery system failure, the operation of the engine is not affected, thus resulting in no engine availability reduction. This work also shows a feasible way to convert the mechanical energy delivered by the recovery turbine into electrical energy, by making use of a high-speed electrical generator

Doping of inorganic materials in microreactors – preparation of Zn doped Fe₃O₄ nanoparticles

Microreactor systems are now used more and more for the continuous production of metal nanoparticles and metal oxide nanoparticles owing to the controllability of the particle size, an important property in many applications. Here, for the first time, we used microreactors to prepare metal oxide nanoparticles with controlled and varying metal stoichiometry. We prepared and characterised Zn-substituted Fe₃O₄ nanoparticles with linear increase of Zn content (ZnxFe₃−xO₄ with 0 ≤ x ≤ 0.48), which causes linear increases in properties such as the saturation magnetization, relative to pure Fe₃O₄. The methodology is simple and low cost and has great potential to be adapted to the targeted doping of a vast array of other inorganic materials, allowing greater control on the chemical stoichiometry for nanoparticles prepared in microreactors

Surgical treatment of symptomatic degenerative lumbar spondylolisthesis by decompression and instrumented fusion

Degenerative spondylolisthesis is characterized by the slippage of one vertebral body over the one below, with association of intervertebral disc degeneration and degenerative arthritis of the facet joints, which cause spinal stenosis. The aim of this study was to evaluate the clinical and radiographic results of 22 patients with symptomatic degenerative spondylolisthesis, operated on by decompressive laminectomy and instrumented posterolateral fusion associated with interbody fusion (PLIF). Mean age at surgery was 64 years (range, 57\u201372). Clinical results were evaluated on a questionnaire at the last follow-up visit concerning postoperative low back and leg pain, restriction of daily life activities, and resumption of sports activity. Lumbar spine radiographs were used to evaluate the status of fixation devices, the reduction of the spondylolisthesis, the lumbar sagittal balance and the presence of spinal fusion. No intraoperative or postoperative complications were encountered. There were no superficial or deep infections, fixation device loosening, or hardware removal. Mean follow-up time was 4 years (range, 3\u20136 years). Clinical outcome was excellent or good in 19 patients and fair in 3 patients. Preoperatively, mean forward vertebral slipping on neutral lateral radiographs was 5 mm, while postoperatively it decreased to 3 mm. Preoperatively, mean sagittal motion was 3 mm and angular motion was 8\ub0, while postoperatively these values decreased to 1 mm and 1\ub0, respectively. This study demonstrated that spinal decompression followed by transpedicular instrumentation associated with PLIF technique is a valid surgical option for the treatment of degenerative spondylolisthesis with symptomatic spinal stenosis. Clinical outcome, intended as relief of pain and resumption of activity, was improved significantly and fusion rate was high

Ground-based NO2 measurements at the Italian Brewer stations: A pilot study with Global Ozone Monitoring Experiment (GOME)

Ground-based NO2 total column measurements have been collected since 1992 using Brewer spectrophotometry at Rome, an urban site, and Ispra (semirural). These are the only ground-based stations regularly monitoring NO2 in Italy. The methodology of measurement together with the procedure to control its quality is described. From the analysis of the time series it was found that the mean value of the NO2 column is 1.63 DU atRome and 1.60 DU atIspra. A firstat tempt to compare NO2 vertical column densities (VCD) from GOME with those derived from ground-based Brewer measurements, under different atmospheric conditions and measurement time lags is here presented. The results of this pilot study showed unsatisfactory agreement because different atmospheres are probed by GOME and Brewer instruments. The GOME space resolution resulted insufficient to fully characterize the Rome and Ispra highly localized polluted areas

Ground-based NO2 measurements at the Italian Brewer stations: A pilot study with Global Ozone Monitoring Experiment (GOME)

Ground-based NO2 total column measurements have been collected since 1992 using Brewer spectrophotometry at Rome, an urban site, and Ispra (semirural). These are the only ground-based stations regularly monitoring NO2 in Italy. The methodology of measurement together with the procedure to control its quality is described. From the analysis of the time series it was found that the mean value of the NO2 column is 1.63 DU atRome and 1.60 DU atIspra. A firstat tempt to compare NO2 vertical column densities (VCD) from GOME with those derived from ground-based Brewer measurements, under different atmospheric conditions and measurement time lags is here presented. The results of this pilot study showed unsatisfactory agreement because different atmospheres are probed by GOME and Brewer instruments. The GOME space resolution resulted insufficient to fully characterize the Rome and Ispra highly localized polluted areas