Search results for "Pore"
showing 10 items of 929 documents
Charging a Capacitor from an External Fluctuating Potential using a Single Conical Nanopore
2015
We explore the electrical rectification of large amplitude fluctuating signals by an asymmetric nanostructure operating in aqueous solution. We show experimentally and theoretically that a load capacitor can be charged to voltages close to 1 V within a few minutes by converting zero time-average potentials of amplitudes in the range 0.5–3 V into average net currents using a single conical nanopore. This process suggests that significant energy conversion and storage from an electrically fluctuating environment is feasible with a nanoscale pore immersed in a liquid electrolyte solution, a system characteristic of bioelectronics interfaces, electrochemical cells, and nanoporous membranes.
Development of a rapid and highly sensitive biochemical method for the measurement of fungal spore viability. An alternative to the CFU method
2001
Abstract 1 A biochemical method, based on dehydrogenase activity (DHA) measurement, has been developed as an alternative to colony forming unit (CFU) enumeration, for assessing the viability of fungal spores. In viable cells, a tetrazolium salt (MTT) is reduced to a coloured formazan (MTTf) by cellular dehydrogenase enzymes. From the colorimetric assay developed by Mosmann for mammalian cells, the procedure has been adapted and optimised using P. digitatum spores as a model. Propan-2-ol has been selected as the best solvent to extract the MTTf from the spores. The sensitivity of the method has been considerably increased by determining the optimal conditions of incubation for the MTT reduct…
HR3DHG version 1: modeling the spatiotemporal dynamics of mercury in the Augusta Bay (southern Italy)
2020
The biogeochemical dynamics of Hg, and specifically of its three species Hg0, HgII, and MeHg (elemental, inorganic, and organic, respectively), in the marine coastal area of Augusta Bay (southern Italy) have been explored by the high-resolution 3D Hg (HR3DHG) model, namely an advection–diffusion–reaction model for dissolved mercury in the seawater compartment coupled with a diffusion–reaction model for dissolved mercury in the pore water of sediments in which the desorption process for the sediment total mercury is taken into account. The spatiotemporal variability of the mercury concentration in both seawater ([HgD]) and the first layers of bottom sediments ([HgDsed] and [HgTsed]), as well…
Direct investigation of viscosity of an atypical inner membrane of Bacillus spores: A molecular rotor/FLIM study
2013
Abstract We utilize the fluorescent molecular rotor Bodipy-C12 to investigate the viscoelastic properties of hydrophobic layers of bacterial spores Bacillus subtilis. The molecular rotor shows a marked increase in fluorescence lifetime, from 0.3 to 4 ns, upon viscosity increase from 1 to 1500 cP and can be incorporated into the hydrophobic layers within the spores from dormant state through to germination. We use fluorescence lifetime imaging microscopy to visualize the viscosity inside different compartments of the bacterial spore in order to investigate the inner membrane and relate its compaction to the extreme resistance observed during exposure of spores to toxic chemicals. We demonstr…
Anthropogenic disturbance and diversity of species: polypores and polypore-associated beetles in forest, forest edge and clear-cut
2005
In boreal coniferous forests, artificial edges often modify the habitat, increasing the likelihood that the diversity and composition of species changes. This study examined the assemblage of polypores and polypore-associated beetles at the edge of mature managed spruce-dominated forests and clear-cuts. The highest number of polypore occurrences and the greatest diversity of polypore species occurred at the clear-cut. In south-facing edges polypores occurred closer to the edge both in clear-cut and in forest than in the north-facing edges. The number of polypore-associated beetle individuals was greatest in the clear-cut, but there was no effect of edge on species richness of beetles. Orien…
Querelle épigraphique entre deux savants : l’exemple de la correspondance, publiée dans la Revue archéologique de 1847, entre Antoine-Jean Letronne e…
2020
Although Roman inscriptions have attracted interest since the Renaissance, epigraphy was not acknowledged as a science in its own right, with its own ruleset and methods, until the mid-19th century. Henceforth every newly discovered inscription was duly documented and distributed across an ever-growing and influential network of European scholars, giving birth to an extensive system of scholarly correspondence connecting every individual researcher with the community, from the provincial antiquarian who, as a precursor to « field archaeology », would discover the inscriptions, to the Parisian scholar who would gather and examine every inscription sent his way. One such epistolary intercours…
Revendication. Obligation de revendiquer, Application, Biens incorporels, Brevet d'invention (oui)
1997
International audience; (Com. 22 oct. 1996, Marmeys c/ Charrière, ès qual.)
A unique microstructure of the fiber networks deposited from foam-fiber suspensions
2015
Abstract Fiber networks can be formed using aqueous foam as the suspending medium. The mean bubble size of the foam affects the resulting pore-size distribution of the fiber network. The foam–fiber interactions cause in particular an increase in the proportion of large micropores of the network, in comparison with the fiber networks that result from traditional water forming at a similar material density. Experiments were carried out for two different types of cellulose fiber, and characterization of the resulting pore structure was based on X-ray microtomography of the resulting fiber networks. The unique pore structure obtained with foam forming was reflected in various macroscopic proper…
Perforin deficiency attenuates inflammation and tumor growth in colitis-associated cancer
2010
Background: Patients with inflammatory bowel disease (IBD) have a markedly increased risk to develop colon cancer, but there are only limited data about the host antitumor response in such colitis-associated cancer. In the present study we aimed at assessing the role of perforin-dependent effector mechanisms in the immune response in a murine model of colitis-associated colon cancer. Methods: Wildtype and perforin-deficient mice were analyzed in a mouse model of colitis-associated colon cancer using azoxymethane (AOM) and dextran sodium sulfate (DSS). Results: Tumors of wildtype mice showed infiltration of CD4+, CD8+ T cells, natural killer (NK) cells, high numbers of apoptotic cells, and e…
Extracorporeal shock waves increase markers of cellular proliferation in primary bronchial fibroblasts of COPD patients
2019
COPD is due to a remodeling of small airways and destruction of the lung parenchyma with loss of the alveolar attachment as a result of pulmonary emphysema. Treatment of connective tissue fibroblasts with extracorporeal shock waves (ESW) increases their cellular proliferation and differentiation. To date no studies are available on ESW treatment of human primary bronchial fibroblasts from COPD and control subjects. Primary bronchial fibroblasts were obtained from bronchial biopsies from three patients with mild/moderate COPD and 3 control smokers with normal lung function. After stabilization for 24h, 1 ml of cell suspension (106 cells) from COPD and controls was treated in 2 ml tubes with …