Microstructural analysis of residual projectiles—A new method to explain penetration mechanisms

In the present work it is shown that metallographic analysis can supply a lot of detailed information about metallurgical events which happen during the penetration of metallic projectiles into armor steel. With the help of these findings models of penetration processes are derived. The deformation, fracture, and phase transformation processes of projectiles are investigated, which consist of tungsten, a tool steel, and a tungsten heavy metal, respectively. These were shot into armor steel at velocities between 1000m/s and 2000 m/s. The extensively deformed tungsten and the brittle steel form two opposite poles; between those the heavy metal takes a mid position. The more ductile a material is, the sooner its penetration approaches the piercing of a liquid jet. On the other hand, in a brittle material quick rupture is followed by turbulent motion and friction welding of the fragments. In this case extensive deformation is observed only in the skin layer of a fragment and in shear bands. Special attention is drawn to features which are characteristic for ballistic piercing processes,e.g., molten films and adiabatic shear deformation. Formerly Research Scientist at the Hochschule der Bundeswehr in Hamburg, West Germany, and thereafter at an institute in France doing military research     

Low temperature fabrication of magnesium phosphate cement scaffolds by 3D powder printing

Synthetic bone replacement materials are of great interest because they offer certain advantages compared with organic bone grafts. Biodegradability and preoperative manufacturing of patient specific implants are further desirable features in various clinical situations. Both can be realised by 3D powder printing. In this study, we introduce powder-printed magnesium ammonium phosphate (struvite) structures, accompanied by a neutral setting reaction by printing farringtonite (Mg₃(PO₄)₂) powder with ammonium phosphate solution as binder. Suitable powders were obtained after sintering at 1100°C for 5 h following 20–40 min dry grinding in a ball mill. Depending on the post-treatment of the samples, compressive strengths were found to be in the range 2–7 MPa. Cytocompatibility was demonstrated in vitro using the human osteoblastic cell line MG63.     

APC的InfraStruXure~(英飞)设计 为思科亚太区NSITE提供强有力支撑

英飞集成系统实际给我们提供了一种方案:目前,我们可以根据现在的需求而选择40kW的功率,当我们的业务增长时,英飞集成系统可以轻松升级以适应我们的需要。"     

Comparative Assessment of Complex Stabilities of Radiocopper Chelating Agents by a Combination of Complex Challenge and in vivo Experiments

For ⁶⁴Cu radiolabeling of biomolecules to be used as in vivo positron emission tomography (PET) imaging agents, various chelators are commonly applied. It has not yet been determined which of the most potent chelators—NODA‐GA ((1,4,7‐triazacyclononane‐4,7‐diyl)diacetic acid‐1‐glutaric acid), CB‐TE2A (2,2′‐(1,4,8,11‐tetraazabicyclo[6.6.2]hexadecane‐4,11‐diyl)diacetic acid), or CB‐TE1A‐GA (1,4,8,11‐tetraazabicyclo[6.6.2]hexadecane‐4,11‐diyl‐8‐acetic acid‐1‐glutaric acid)—forms the most stable complexes resulting in PET images of highest quality. We determined the ⁶⁴Cu complex stabilities for these three chelators by a combination of complex challenge and an in vivo approach. For this purpose, bioconjugates of the chelating agents with the gastrin‐releasing peptide receptor (GRPR)‐affine peptide PESIN and an integrin α_vβ₃‐affine c(RGDfC) tetramer were synthesized and radiolabeled with ⁶⁴Cu in excellent yields and specific activities. The ⁶⁴Cu‐labeled biomolecules were evaluated for their complex stabilities in vitro by conducting a challenge experiment with the respective other chelators as challengers. The in vivo stabilities of the complexes were also determined, showing the highest stability for the ⁶⁴Cu–CB‐TE1A‐GA complex in both experimental setups. Therefore, CB‐TE1A‐GA is the most appropriate chelating agent for *Cu‐labeled radiotracers and in vivo imaging applications.     

Conversion of a Mono‐ and Diacylglycerol Lipase into a Triacylglycerol Lipase by Protein Engineering

Despite the fact that most lipases are believed to be active against triacylglycerides, there is a small group of lipases that are active only on mono‐ and diacylglycerides. The reason for this difference in substrate scope is not clear. We tried to identify the reasons for this in the lipase from Malassezia globosa. By protein engineering, and with only one mutation, we managed to convert this enzyme into a typical triacylglycerol lipase (the wild‐type lipase does not accept triacylglycerides). The variant Q282L accepts a broad spectrum of triacylglycerides, although the catalytic behavior is altered to some extent. From in silico analysis it seems that specific hydrophobic interactions are key to the altered substrate specificity.     

持续的绿色世界

在人类面临全球性环境污染和生态破坏的今天,可持续发展的概念已在有关自然、环境、经济、社会、科技等相关讨论中无处不在,能既满足当代人的需求,又不破坏后代人的需求已经是当今全球范围内最重视的研究课