176 research outputs found
Mercury acetate produced by metallic mercury subjected to acoustic cavitation in a solution of acetic acid in water.
Mercury acetate (MA) can be obtained by metallic mercury immersed in a mixture of deionised, bidistillated water (dbw) and acetic acid. We show that MA crystallization time is drastically reduced if the previous mixtures are subjected to acoustic cavitation. The largest quantity of crystals is obtained by a concentration of acetic acid of about 7% in volume. NMR analysis of identical mixtures in the presence of mercury, performed as soon as possible after cavitation, showed the largest quantity of mercury acetate molecules, for the same concentration of acetic acid of 7% in volume
Post-eruption morphological evolution and vegetation dynamics of the Blanco River, southern Chile
In this study, we analysed the morphological evolution of a channel segment in the Blanco River in southern Chile that was affected by the Chaitén Volcano eruption occurred in 2008–2009. Through a series of high-resolution satellite images from 2005 to 2019 that represents the entire pre- and post-eruptive dynamics and land covers, we tracked the geomorphological evolution of a 5.65-km-long river segment using channel form indices and also monitored the vegetation dynamics using object-based image analysis (OBIA). Discharge record for the Blanco River was also reconstructed to support the analysis of channel morphologic process. The study aims at examining whether a) the river channel is still adjusting 10 years after the eruption and if so, at what magnitude and, b) the recovered riparian vegetation plays a significant role in stabilising the river streambanks and terraces. We found that even 10 years after the eruption, the Blanco River channel planform is still adjusting, showing a simpler and stable channel configuration in the upstream reaches of the valley, where a certain degree of equilibrium appears to have been attained. More dynamic morphologies were observed in the reaches downstream that have to accommodate the arrival of large amounts of freshly eroded sediments. Our analysis showed that the occurrence of competent floods capable of reworking the river channel matches with the geomorphic indices and mark the post-eruption adjustments of the channel. Finally, the in-channel and riparian vegetation does not play a significant role in stabilising the active channel, streambanks, and terraces, reinforcing the recolonization of sedimentary active areas occurring elsewhere in the valley.This research was developed within the frame of the project FONDECYT 1170413 funded by the Chilean Government. Authors acknowledge the support of the Economy and Knowledge Department of the Catalan Government through the Fluvial Dynamics Research Group (RIUS) SGR017-459
Autochthonous European dirofilariasis of the lung
Two intrapulmonary round nodules were identified by x-ray examination in a 45-year old German woman during an examination conducted before her employment who had been complaining of pain in the right side of the thorax and of mild coughing irritation and tiredness for several months prior to the health check. Since the intraoperative frozen section did not show any malignancy, and atypical resection of the two involved segments was performed. Histological processing of the surgical specimens showed two spherical ischemic necroses surrounded by a connective tissue border with inflammatory infiltration. In the centre of the larger of the two necrotic lesions a parasite was seen intravascularly, which because of morphological and serological findings, was identified as a Dirofilaria. It must be assumed that the infection of this patient occurred during a stay in Corsica where these nematodes are endemic in several mammal hosts. The patient was therefore suffering from an autochthonous European dirofilariasis of the lung. Only two cases of this infection acquired in Europe have been reported so far
Carcinoid tumours of the lung and the ’PEPPS’ approach: evaluation of preoperative bronchoscopic tumour debulking as preparation for subsequent parenchyma-sparing surgery
BACKGROUND: Preoperative bronchoscopic tumour ablation has been suggested as a beneficial treatment for bronchopulmonary carcinoid tumours, although data regarding its effects and long-term outcome are lacking. METHODS: In our case-matched cohort study with 208 patients with bronchopulmonary carcinoid tumours we investigated the role of preoperative bronchoscopic interventions before subsequent surgery and analysed the safety of this Procedure of Endobronchial Preparation for Parenchyma-sparing Surgery (PEPPS) based on metastasis and recurrence rates as well as survival data from 1991 to 2010. The subsequent surgery was classified into parenchyma-sparing procedures and classical lobectomies, bilobectomies and pneumonectomies. Data were obtained from the tumour registry and medical reports. Outcomes were the frequency of parenchyma-sparing surgery after bronchoscopic treatment as well as rates of metastasis, recurrence and survival. RESULTS: 132 of 208 carcinoids were located centrally. Among them, 77 patients could be recanalised preoperatively. After bronchoscopic preparation, the rate of subsequent parenchyma-sparing surgery methods was higher (p=0.021). The effect was measured by the number of segments removed. The 10-year survival rate was 89% (typical carcinoids) and 68% (atypical carcinoids), respectively. After applying PEPPS, long-term survival was slightly higher (p=0.23). Metastasis and recurrence rates showed no relevant differences between the bronchoscopically treated or non-treated groups, or between the two types of surgery classes or between the PEPPS and non-PEPPS groups. CONCLUSIONS: After preoperative bronchoscopic treatment, parenchyma-sparing surgery techniques can be applied more frequently. Furthermore, we detected no negative effects after PEPPS based on metastasis, recurrence and survival rates
Phytochemical profiling, antibacterial and antioxidant properties of Crocus sativus flower: A comparison between tepals and stigmas
Several studies have demonstrated that stigmas of Crocus sativus contain several bioactive compounds with potential health-promoting properties. However, during the processing of stigmas, large amounts of floral bio-residues are normally discarded as by-products. In this study, using untargeted metabolomics, the comprehensive phytochemical composition of C. sativus stigma and tepals was investigated. Moreover, the antibacterial and anti-biofilm properties of the extracts of C. sativus stigmas and tepals were compared. The study was carried out using two methicillin-resistant staphylococcal reference strains (i.e., Staphylococcus aureus ATCC 43300 and Staphylococcus epidermidis ATCC 35984), representing important Gram-positive biofilm-forming human pathogens. The antibacterial properties were correlated with total polyphenol content, total terpenoid content, and in vitro antioxidant properties of tepals and stigmas. The results demonstrated that stigma and tepal extracts, at the sub-toxic concentrations, were able to interfere with biofilm formation by ATCC 43300 and ATCC 35984. Besides, the higher antibacterial activity of tepals than stigmas was associated with higher levels of phycompounds. Therefore, our results demonstrated that C. sativus stigmas and bio-residues, such as tepals, are potential antioxidant sources and good candidates as antibacterial agents to prevent biofilm formation. Taken together, these findings showed that C. sativus could be used as functional ingredient by the food and pharmaceutical industries
Influencia del bienestar psicológico en la vulnerabilidad a conductas adictivas en adolescentes escolarizados de 15 a 18 años. Estudio piloto.
Numerosas investigaciones (Casullo, 2002; Castro Solano, 2002; Rodrigo y otros, 2004; Observatorio Argentino de Drogas, 2009), han demostrado la relación inversa entre el nivel de bienestar psicológico (BP) y conductas de riesgo en adolescentes. La hipótesis de este estudio es que la identificación de indicadores de bajo nivel de BP puede contribuir a la detección de adolescentes en riesgo adictivo
High-performance versatile setup for simultaneous Brillouin-Raman micro-spectroscopy
This is the author accepted manuscript. The final version is available from American Physical Society via the DOI in this record.Brillouin and Raman scattering spectroscopy are established techniques for the nondestructive contactless and label-free readout of mechanical, chemical and structural properties of condensed matter. Brillouin-Raman investigations currently require separate measurements and a site-matched approach to obtain complementary information from a sample.
Here we demonstrate a new concept of fully scanning multimodal micro-spectroscopy for simultaneous detection of Brillouin and Raman light scattering in an exceptionally wide spectral range, from fractions of GHz to hundreds of THz. It yields an unprecedented 150 dB contrast, which is especially important for the analysis of opaque or turbid media such as biomedical samples, and spatial resolution on a sub-cellular scale.
We report the first applications of this new multimodal method to a range of systems, from a single cell to the fast reaction kinetics of a curing process, and the mechano-chemical mapping of highly scattering biological samples.S. Corezzi acknowledges financial support from MIUR-PRIN (Project No. 2012J8X57P). S. Caponi acknowledges support from PAT (Provincia Autonoma di Trento) (GP/PAT/2012) “Grandi Progetti 2012” Project “MaDEleNA.” P. S., A. M., M. P. acknowledge financial support from Centro Nazionale Trapianti (Project: “Studio di cellule per uso clinico umano, con particolare riferimento a modelli cellulari (liposomi) e linee cellulari in interazione con crioconservanti e con materiali biocompatibili”). L. C. and S. Caponi acknowledge financial support from Consiglio Nazionale delle Ricerche-Istituto Officina dei Materiali. F. P. acnowledges support from the UK Engineering and Physical Sciences Research Council (Grant No. EP/M028739/1 (F. P.)). The authors acknowledge Jacopo Scarponi for valuable help in setting up the hardware and software system for simultaneous Raman and BLS measurements
A novel combined experimental and multiscale theoretical approach to unravel the structure of SiC/SiOx core/shell nanowires for their optimal design
In this work we propose a realistic model of nanometer-thick SiC/SiOxcore/shell nanowires (NWs) using a combined first-principles and experimental approach. SiC/SiOxcore/shell NWs were first synthesised by a low-cost carbothermal method and their chemical-physical experimental analysis was accomplished by recording X-ray absorption near-edge spectra. In particular, the K-edge absorption lineshapes of C, O, and Si are used to validate our computational model of the SiC/SiOxcore/shell NW architectures, obtained by a multiscale approach, including molecular dynamics, tight-binding and density functional simulations. Moreover, we present ab initio calculations of the electronic structure of hydrogenated SiC and SiC/SiOxcore/shell NWs, studying the modification induced by several different substitutional defects and impurities into both the surface and the interfacial region between the SiC core and the SiOxshell. We find that on the one hand the electron quantum confinement results in a broadening of the band gap, while hydroxyl surface terminations decrease it. This computational investigation shows that our model of SiC/SiOxcore/shell NWs is capable to deliver an accurate interpretation of the recorded X-ray absorption near-edge spectra and proves to be a valuable tool towards the optimal design and application of these nanosystems in actual devices
Effect of DMSO on the mechanical and structural properties of model and biological membranes
This is the final version. Available from Elsevier via the DOI in this recordDimethyl sulfoxide (DMSO) is widely used in a number of biological and biotechnological applications, mainly
because of its effects on the cell plasma membrane, but the molecular origins of this action are yet to be fully clarified. In this
work, we used two- and three-component synthetic membranes (liposomes) and the plasma membrane of human erythrocytes
to investigate the effect of DMSO when added to the membrane-solvating environment. Fourier transform infrared spectroscopy
and thermal fluctuation spectroscopy revealed significant differences in the response of the two types of liposome systems to
DMSO in terms of the bilayer thermotropic behavior, available free volume of the bilayer, its excess surface area, and bending
elasticity. DMSO also alters the mechanical properties of the erythrocyte membrane in a concentration-dependent manner and
is capable of increasing membrane permeability to ATP at even relatively low concentrations (3% v/v and above). Taken in its
entirety, these results show that DMSO is likely to have a differential effect on heterogeneous biological membranes, depending
on their local composition and structure, and could affect membrane-hosted biological functions.Engineering and Physical Sciences Research Council (EPSRC
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