We define the characteristic cycle of an étale sheaf as a cycle on the cotangent bundle of a smooth variety in positive characteristic using the singular support recently defined by Beilinson. We ...prove a formula à la Milnor for the total dimension of the space of vanishing cycles and an index formula computing the Euler–Poincaré characteristic, generalizing the Grothendieck–Ogg–Shafarevich formula to higher dimension. An essential ingredient of the construction and the proof is a partial generalization to higher dimension of the semi-continuity of the Swan conductor due to Deligne–Laumon. We prove the index formula by establishing certain functorial properties of characteristic cycles.
A clustered DNA damage site (cluster), in which two or more lesions exist within a few helical turns, is believed to be a key factor determining the fate of a living cell exposed to a DNA damaging ...agent such as ionizing radiation. However, the structural details of a cluster such as the number of included lesions and their proximity are unknown. Herein, we develop a method to characterize a cluster by fluorescence anisotropy measurements based on Förster resonance energy transfer (homo-FRET). Plasmid DNA (pUC19) was irradiated with 2.0 and 0.52 MeV/u
4
He
2+
, or 0.37 MeV/u
12
C
5+
ion beams (linear energy transfer: ~ 70, ~ 150, ~ 760 keV/μm, respectively) and
60
Co γ-rays as a standard (~ 0.2 keV/μm) in the solid state. The irradiated DNA was labeled with an aminooxyl fluorophore (Alexa Fluor 488) to the aldehyde/ketone moieties such as apurinic/apyrimidinic sites. Homo-FRET analyses provided the apparent base separation values between lesions in a cluster produced by each ion beam track as 21.1, 19.4, and 18.7 base pairs. The production frequency of a cluster increases with increasing linear energy transfer of radiation. Our results demonstrate that homo-FRET analysis has the potential to discover the qualitative and the quantitative differences of the clusters produced not only by a variety of ionizing radiation but also by other DNA damaging agents.
We show that the characteristic cycle of the external product of constructible complexes is the external product of the characteristic cycles of the factors. This implies the compatibility of ...characteristic cycles with smooth pull-back which is a first step in the proof of the index formula.
► New sample-preparation methods for drug analysis in biological materials. ► The advantages of monolithic materials in bioanalysis. ► Devices for polymer monolith microextraction, pipette-tip and ...spin-column extraction. ► We describe promising sample-extraction methods for monolithic materials.
Monoliths were first used as materials for chromatographic separation 20years ago and as extraction sorbents for solid-phase extraction over 10years ago.
Recently, monolithic silica and polymers were modified to suit devices for extraction and enrichment of analytes in matrices for environmental, food and biological analyses. This approach contributed to miniaturization and automation, which can reduce the time and the cost of sample preparation. Numerous applications were demonstrated for on-line and in-line preconcentration with monoliths, and many kinds of off-line device were designed and developed.
This review discusses trends in these device and applications.
We propose a design and fabrication process for fabrics containing thermoelectric generators (TEGs) in the form of carbon nanotube composite threads intended for energy harvesting of low-temperature ...waste heat. Our prototype thermoelectric fabric with an integrated p/n-stripe-patterned CNT thread shows potential as an easy-to-use power source for wearable electronics.
Display omitted
With the development of nanotechnology, silver nanoparticles (Ag-NPs) have become one of the most in-demand nanoparticles owing to their exponential number of uses in various sectors. ...The increased use of Ag-NPs-enhanced products may result in an increased level of toxicity affecting both the environment and living organisms. Several studies have used different model cell lines to exhibit the cytotoxicity of Ag-NPs, and their underlying molecular mechanisms. This review aimed to elucidate different properties of Ag-NPs that are responsible for the induction of cellular toxicity along with the critical mechanism of action and subsequent defense mechanisms observed in vitro. Our results show that the properties of Ag-NPs largely vary based on the diversified synthesis processes. The physiochemical properties of Ag-NPs (e.g., size, shape, concentration, agglomeration, or aggregation interaction with a biological system) can cause impairment of mitochondrial function prior to their penetration and accumulation in the mitochondrial membrane. Thus, Ag-NPs exhibit properties that play a central role in their use as biocides along with their applicability in environmental cleaning. We herein report a current review of the synthesis, applicability, and toxicity of Ag-NPs in relation to their detailed characteristics.
PDF
