274 research outputs found

    The most common laboratory procedures for the evaluation of EPB TBMs excavated material ecotoxicity in Italy: A review

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    The rapid development of the mechanized tunneling in current decades has raised serious concerns about the environmental impact of large quantities of the muck. EPB-TBMs require the use of foaming agents for optimizing the soil conditioning.These agents could contain some chemicals (e.g., sodium lauryl ether sulfate – SLES) that are not included in the current legislation at the Italian or EU level. In order to minimize the project costs, it is useful to re-use the excavated soil as a reusable by-product that requires that it does not have any environmental impact on the ecosystems. For this purpose, to draw up a site-specific protocol is a practical and successful tool to evaluate the environmental compatibility of excavated soil during the tunneling. It can rely on one-month experiments at a microcosm or mesocosm scale using soil coming from the excavated site.At fixed times (from 0 to 28 days) the chemical degradation of the chemical together with ecotoxicological tests can be performed on soil or soil-water extracts. Both aquatic and terrestrial organisms are used and the choice of the tests depends on the final destination site.The results of the residual concentration of SLES in soil and in the elutriates, together with those of the ecotoxicological tests, make it possible to evaluate the temporary storage of spoil material and the time necessary for obtaining a safe soil debris to be used as a by-product.These data are usually included in the site-specific protocol to be applied during the excavation phase.This paper describes the main methodological aspects regarding microcosm experiments

    Bis(phenyl­sulfin­yl)methane

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    Two independent mol­ecules comprise the asymmetric unit of the title compound, C13H12O2S2, which differ in terms of minor variations in the relative orientations of the benzene rings [the O–S–C–C torsion angles for the first independent mol­ecule are −6.66 (17) and −12.88 (19)° compared with −21.70 (18) and 4.83 (16)° for the second mol­ecule]. Supra­molecular chains sustained by C—H⋯O contacts and aligned along the a axis are found in the crystal structure. These are held in place in the three dimensional structure by C—H⋯π inter­actions

    Effect of aminophylline in preventing renal dysfunction among neonates with prenatal asphyxia: A clinical trial

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    Background: As there are different views on the effects of aminophylline on neonatal renal function, we intended to observe the effects of aminophylline on renal dysfunction in neonates with prenatal asphyxia. Methods: This randomized trial was conducted in the Obstetrics and Gynecology Hospital, Tehran, Iran, from June 2016 to May 2017, in neonates with moderate to severe asphyxia during birth. Fifty-six neonates were divided randomly into two groups. The intervention group received one dose of 5mg/kg slow intravenous aminophylline injection and the placebo group received 2 mL/kg of intravenous 10 solution of dextrose saline during the first hour of life. They were monitored and compared for renal functional indices, electrolytes, and complications of asphyxia during the three days of life. Results: The mean of Cr (37.9 ± 8.8 vs 38.5 ± 9.4 and 20.8 ± 4.8 vs 30.1 ± 5.2 μmol/L), GFR (21.55 ± 4.7 vs 20.25 ± 4.4 and 30.8 ± 7.1 vs 20.1 ± 6.5 mL/minute/1.73 m2), Na (135.1 ± 12.4 vs134.5 ± 11.2 and 128.9 ± 11.5 vs 134.2 ± 10.9 mEq/L), and urine output (98.2 ± 25 vs 96.8 ± 23 and 148.7 ± 35 vs 108.8 ± 20 cc) were in the aminophylline treated and placebo group on the 1st and 3rd days, respectively. The mean difference of Cr (-9.3 (-8.9; -9.7) μmol/L); (P = 0.02), GFR (10.7 (10.1; 11.3) mL/minute/1.73 m2) (P = 0.009), Na (-5.3 (-5.9; -4.7) mEq/L) (P = 0.002), and urine volume (39.9 (24.9; 54.9) cc) (P = 0.001) presented statistically significant differences on the third day between the intervention and placebo group. Conclusion: Aminophylline was effective in preventing renal dysfunction in neonates with asphyxia. Neonates who received aminophylline indicated a significant improvement in GFR and urine output on the first day of life. © 2020 The authors and IJLTER.ORG. All rights reserved

    Synergistic Antibacterial Effects of Metallic Nanoparticle Combinations

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    © The Author(s) 2019.Metallic nanoparticles have unique antimicrobial properties that make them suitable for use within medical and pharmaceutical devices to prevent the spread of infection in healthcare. The use of nanoparticles in healthcare is on the increase with silver being used in many devices. However, not all metallic nanoparticles can target and kill all disease-causing bacteria. To overcome this, a combination of several different metallic nanoparticles were used in this study to compare effects of multiple metallic nanoparticles when in combination than when used singly, as single elemental nanoparticles (SENPs), against two common hospital acquired pathogens (Staphylococcus aureus and Pseudomonas. aeruginosa). Flow cytometry LIVE/DEAD assay was used to determine rates of cell death within a bacterial population when exposed to the nanoparticles. Results were analysed using linear models to compare effectiveness of three different metallic nanoparticles, tungsten carbide (WC), silver (Ag) and copper (Cu), in combination and separately. Results show that when the nanoparticles are placed in combination (NPCs), antimicrobial effects significantly increase than when compared with SENPs (P < 0.01). This study demonstrates that certain metallic nanoparticles can be used in combination to improve the antimicrobial efficiency in destroying morphologically distinct pathogens within the healthcare and pharmaceutical industry.Peer reviewe

    Analytical protocols for separation and electron microscopy of nanoparticles interacting with bacterial cells

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    An important step toward understanding interactions between nanoparticles (NPs) and bacteria is the ability to directly observe NPs interacting with bacterial cells. NPbacteria mixtures typical in nanomedicine, however, are not yet amendable for direct imaging in solution. Instead, evidence of NPcell interactions must be preserved in derivative (usually dried) samples to be subsequently revealed in high-resolution images, e.g., via scanning electron microscopy (SEM). Here, this concept is realized for a mixed suspension of model NPs and Staphylococcus aureus bacteria. First, protocols for analyzing the relative colloidal stabilities of NPs and bacteria are developed and validated based on systematic centrifugation and comparison of colony forming unit (CFU) counting and optical density (OD) measurements. Rate-dependence of centrifugation efficiency for each component suggests differential sedimentation at a specific predicted rate as an effective method for removing free NPs after co-incubation; the remaining fraction comprises bacteria with any associated NPs and can be examined, e.g., by SEM, for evidence of NPbacteria interactions. These analytical protocols, validated by systematic control experiments and high-resolution SEM imaging, should be generally applicable for investigating NPbacteria interactions.financial support from the following sources: grant SFRH/BPD/47693/2008 from the Portuguese Foundation for Science and Technology (FCT); FCT Strategic Project PEst-OE/EQB/LA0023/2013; project “BioHealth Biotechnology and Bioengineering approaches to improve health quality”, Ref. NORTE-07-0124-FEDER-000027, cofunded by the Programa Operacional Regional do Norte (ON.2−O Novo Norte), QREN, FEDER; project “Consolidating Research Expertise and Resources on Cellular and Molecular Biotechnology at CEB/IBB”, ref. FCOMP-01-0124-FEDER- 027462

    Using metrics and sustainability considerations to evaluate the use of bio-based and non-renewable Brønsted acidic ionic liquids to catalyse Fischer esterification reactions

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    Background Ionic liquids have found uses in many applications, one of which is the joint solvation and catalysis of chemical transformations. Suitable Brønsted acidic ionic liquids can be formed by combining lactams with sulphonic acids. This work weighs up the relative benefits and disadvantages of applying these Brønsted acidic ionic liquid catalysts in esterifications through a series of comparisons using green chemistry metrics. Results A new bio-based ionic liquid was synthesised from N-methyl pyrrolidinone and p-cymenesulphonic acid, and tested as a catalyst in three Fischer esterifications under different conditions. An evaluation of the performance of this Brønsted acidic ionic liquid was made through the comparison to other ionic liquid catalysts as well as conventional homogeneous Brønsted acids. Conclusion Extending the argument to feedstock security as well as mass utilisation, ultimately in most instances traditional mineral acids appear to be the most sensible option for Brønsted acid esterification catalysts. Ester yields obtained from Brønsted acidic ionic liquid catalysed procedures were modest. This calls into question the diversity of research exploring esterification catalysis and the role of ionic liquids in esterifications

    Nanotechnology intervention of the microbiome for cancer therapy

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    The microbiome is emerging as a key player and driver of cancer. Traditional modalities to manipulate the microbiome (for example, antibiotics, probiotics and microbiota transplants) have been shown to improve efficacy of cancer therapies in some cases, but issues such as collateral damage to the commensal microbiota and consistency of these approaches motivates efforts towards developing new technologies specifically designed for the microbiome–cancer interface. Considering the success of nanotechnology in transforming cancer diagnostics and treatment, nanotechnologies capable of manipulating interactions that occur across microscopic and molecular length scales in the microbiome and the tumour microenvironment have the potential to provide innovative strategies for cancer treatment. As such, opportunities at the intersection of nanotechnology, the microbiome and cancer are massive. In this Review, we highlight key opportunistic areas for applying nanotechnologies towards manipulating the microbiome for the treatment of cancer, give an overview of seminal work and discuss future challenges and our perspective on this emerging area

    Bio-mimicking nano and micro-structured surface fabrication for antibacterial properties in medical implants

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