Monitoring reversion of hepatitis C virus-induced cellular alterations by direct-acting antivirals using cryo soft X-ray tomography and infrared microscopy.

Hepatitis C virus (HCV) is an enveloped RNA virus. One of the hallmarks of HCV infection is a rearrangement of the host cell membranes, known as the `membranous web'. Full-field cryo soft X-ray tomography (cryo-SXT) in the water-window energy range (284-543 eV) was performed on the MISTRAL beamline to investigate, in whole unstained cells, the morphology of the membranous rearrangements induced in HCV replicon-harbouring cells in conditions close to the living physiological state. All morphological alterations could be reverted by a combination of sofosbuvir/daclatasvir, which are clinically approved antivirals (direct-acting antivirals; DAAs) for HCV infection. Correlatively combining cryo-SXT and 2D synchrotron-based infrared microscopy provides critical information on the chemical nature of specific infection-related structures, which allows specific patterns of the infection process or the DAA-mediated healing process to be distinguished.

A 3D Cartographic Description of the Cell by Cryo Soft X-ray Tomography.

Imaging techniques are fundamental in order to understand cell organization and machinery in biological research and the related fields. Among these techniques, cryo soft X-ray tomography (SXT) allows imaging whole cryo-preserved cells in the water window X-ray energy range (284-543 eV), in which carbon structures have intrinsically higher absorption than water, allowing the 3D reconstruction of the linear absorption coefficient of the material contained in each voxel. Quantitative structural information at the level of whole cells up to 10 µm thick is then achievable this way, with high throughput and spatial resolution down to 25-30 nm half-pitch. Cryo-SXT has proven itself relevant to current biomedical research, providing 3D information on cellular infection processes (virus, bacteria, or parasites), morphological changes due to diseases (such as recessive genetic diseases) and helping us understand drug action at the cellular level, or locating specific structures in the 3D cellular environment. In addition, by taking advantage of the tunable wavelength at synchrotron facilities, spectro-microscopy or its 3D counterpart, spectro-tomography, can also be used to image and quantify specific elements in the cell, such as calcium in biomineralization processes. Cryo-SXT provides complementary information to other biological imaging techniques such as electron microscopy, X-ray fluorescence or visible light fluorescence, and is generally used as a partner method for 2D or 3D correlative imaging at cryogenic conditions in order to link function, location, and morphology.

MISTRAL: a transmission soft X-ray microscopy beamline for cryo nano-tomography of biological samples and magnetic domains imaging.

The performance of MISTRAL is reported, the soft X-ray transmission microscopy beamline at the ALBA light source (Barcelona, Spain) which is primarily dedicated to cryo soft X-ray tomography (cryo-SXT) for three-dimensional visualization of whole unstained cells at spatial resolutions down to 30 nm (half pitch). Short acquisition times allowing for high-throughput and correlative microscopy studies have promoted cryo-SXT as an emerging cellular imaging tool for structural cell biologists bridging the gap between optical and electron microscopy. In addition, the beamline offers the possibility of imaging magnetic domains in thin magnetic films that are illustrated here with an example.

Escória de aciaria na redução da solubilidade e lixiviação de manganês em áreas contaminadas / lmaking slag to reducing the solubility and leaching of manganese in contaminated areas

A escória de aciaria é um rejeito da produção do aço e possui propriedade corretiva da acidez do solo, podendo reduzir consequentemente a mobilidade de elementos traço. O trabalho objetivou avaliar a capacidade do resíduo industrial escória de aciaria em reduzir a solubilidade e lixiviação de Mn em resíduos contaminados. No Laboratório de Poluição de Solos da UFRRJ (Seropédica-RJ), foram realizados ensaios de lixiviação em colunas usando três resíduos contaminados com Mn, denominados G1, G2 e G3 e duas doses de resíduo inertizante (escória de aciaria). Nas colunas, foi aplicado um volume de água conhecido e constante que simula a precipitação máxima ocorrida nos últimos 17 anos na região onde foi coletado o resíduo. A maior dose do resíduo de escória de aciaria (6%) reduziu a solubilidade do Mn a valores inferiores ao limite máximo permitido pela ABNT, nos grupos G1, G2 e G3, sendo que o tratamento com 6% escória de aciaria + barreiras químicas foi o mais eficiente na redução da lixiviação de Mn em todos os grupos de resíduos estudados. Portanto, os resultados evidenciaram a eficiência da escória de aciaria na redução da solubilidade e lixiviação do Mn, em todos os resíduos.

Steelmaking slag is a waste of steel production and has owned corrective soil acidity and may consequently reduce the mobility of trace elements. The research aimed the capacity of industrial waste steelmaking slag to reduce the solubility and lixiviation of Mn in contaminated soil. In the Soil Pollution Laboratory of the UFRRJ (Seropédica-RJ), leaching experiments were carried using three different residues contaminated with Mn, and two doses of the inertizant residues steelmaking slag. In the columns were applied a known and constant volume of water, established to simulate the maximum precipitation occurred in the last 17 years, in the region where the residue was collected. The highest dose of steelmaking slag (6%) reduced the Mn solubility below the maximum allowed by ABNT, for G1, G2 and Ge, and the treatment with 6% steelmaking slag + barriers chemical was the most effective in reducing the leaching of Mn in all groups. Therefore, the results showed the efficiency of steelmaking slag in the reduction of Mn solubility and lixiviation in all residues.