Influence of magnetic field on electron beam-induced Coulomb explosion of gold microparticles in transmission electron microscopy.

In this work we instigated the fragmentation of Au microparticles supported on a thin amorphous carbon film by irradiating them with a gradually convergent electron beam inside the Transmission Electron Microscope. This phenomenon has been generically labeled as "electron beam-induced fragmentation" or EBIF and its physical origin remains contested. On the one hand, EBIF has been primarily characterized as a consequence of beam-induced heating.

Inherent Antibacterial Properties of Biodegradable FeMnC(Cu) Alloys for Implant Application.

Implant-related infections or inflammation are one of the main reasons for implant failure. Therefore, different concepts for prevention are needed, which strongly promote the development and validation of improved material designs. Besides modifying the implant surface by, for example, antibacterial coatings (also implying drugs) for deterring or eliminating harmful bacteria, it is a highly promising strategy to prevent such implant infections by antibacterial substrate materials.

Cell Cycle-Mediated Regulation of Secondary Ig Diversification.

Secondary Ig diversification in B cells requires the deliberate introduction of DNA damage into the Ig genes by the enzyme activation-induced cytidine deaminase (AID) and the error-prone resolution of AID-induced lesions. These processes must be tightly regulated because they may lead to lymphomagenesis if they act on genes other than the Ig genes. Since B cells may limit secondary Ig diversification mechanisms during the cell cycle to minimize genomic instability, we restricted the activity of AID specifically to the G1 or S/G2 phase to investigate the cell cycle contribution to the regulation of somatic hypermutation, class switch recombination, and Ig gene conversion in human, murine, and avian B cells, respectively.

A Newly Designed High-Strength Tool Steel with High Wear and Corrosion Resistance.

In this study, a newly developed high-strength cast Fe81Cr15V3C1 (wt%) steel with a high resistance against dry abrasion and chloride-induced pitting corrosion is presented. The alloy was synthesized through a special casting process that yielded high solidification rates. The resulting fine, multiphase microstructure is composed of martensite, retained austenite and a network of complex carbides.

Approach to Estimate the Phase Formation and the Mechanical Properties of Alloys Processed by Laser Powder Bed Fusion via Casting.

A high-performance tool steel with the nominal composition Fe85Cr4Mo8V2C1 (wt%) was processed by three different manufacturing techniques with rising cooling rates: conventional gravity casting, centrifugal casting and an additive manufacturing process, using laser powder bed fusion (LPBF). The resulting material of all processing routes reveals a microstructure, which is composed of martensite, austenite and carbides. However, comparing the size, the morphology and the weight fraction of the present phases, a significant difference of the gravity cast samples is evident, whereas the centrifugal cast material and the LPBF samples show certain commonalities leading finally to similar mechanical properties.