MgAl2O4-Spinel Synthesized by High-Energy Ball Milling and Reaction Sintering

A new way to prepare magnesia-alumina-spinel was investigated making use of a mixed powder system of MgO and metallic Al-3 wt% Mg. Intensive ball milling was applied which provides the formation of new powder particles as composite of both components in intimate contact. The new configuration of the particles had a significant impact on the reaction sintering behavior leading to single phase spinel microstructures at moderate temperatures below 1400°C. Optimized milling of the powder mixture was therefore required providing reduced crystallite sizes and strongly enlarged interfacial area shared by the reacting components. The optimal milling time was identified by the complete reaction of the starting powders to spinel during sintering. Shorter milling times led to incomplete reactions and longer milling times contaminated the milling product by debris from the milling tools. The amount of interfaces generated by the intimate mixing dominated the sintering reaction kinetics whereas the specific surfaces area was of secondary importance.     

TPA‐PPEs – New alternating donor copolymers for potential application in photovoltaic devices

A series of phenyleneethynylene copolymers with triphenylamine units as hole‐transporting moieties (TPA‐PPEs) were synthesized by the palladium‐catalyzed cross‐coupling polycondensation of diethynyltriphenylamines and selected dihalogen comonomers, for instance substituted benzene, thiophene, benzothiadiazole, or anthracene. Incorporation of the electron‐rich amino group into the PPE backbone does not interrupt the main chain conjugation. Furthermore, it has a decreasing effect on the oxidation potential, thus makes these polymers interesting as hole‐injection/hole‐transporting materials. The chemical structure of the new alternating copolymers was confirmed by ¹H and ¹³C NMR spectroscopy and elemental analysis and gel‐permeation chromatography (GPC; THF, M_n ≈ 15,000–30,000 g/mol) was conducted. Furthermore, their optical properties were investigated by UV/vis spectroscopy. The TPA‐PPEs exhibit absorption maxima at around 400 nm (π‐π*), except anthracene containing copolymer 3f (λ_max = 514 nm in THF) and benzothiadiazole containing one 3g (λ_max = 503 nm in THF). The TPA copolymers have oxidation potentials about 1.1 V (Ag/AgCl). They are good photoconducting materials ( 3a : I_Photo = 4 × 10^?10 A at 425 nm (400 V), 3g : I_Photo = 1.3 × 10^?11 A at λ_max = 500 nm (20 V)) and show emission after excitation at around 450 nm (560 nm 3f ). Their application in nonoptimized polymer solar cells (bulk heterojunction) led to power conversion efficiencies of around 1–1.8% after illumination with 100 mW/cm² of AM1.5. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Holistic process planning chain for robot machining

Today, machining of large, integral constructed structural parts requires expensive machining centers. In contrast, modern industrial robots are suitable for a wide field of applications and are characterized large working spaces and low capital investment. Therefore, they provide high economical potential for machining applications in aerospace industry, especially for the machining of near to shape pre-products like extruded profiles. However, their constructive characteristics like low stiffness and high sensitivity to vibrations lead to disadvantages compared with conventional machining centers and have to be considered during process planning. Therefore, several methods for offline and online optimization of robot machining processes were developed and integrated in a new process chain for manufacturing of structural fuselage parts. Thereby, the conventional CAD–CAM process planning chain was extended with simulation based analysis and optimization methods and a load-depending trajectory planning. These methods for offline process optimization within this novel process chain are presented in this paper.     

More distinct food intake patterns among women than men in northern Sweden: a population-based survey

Background

The need to promote a healthy diet to curb the current obesity epidemic has today been recognized by most countries. A prerequisite for planning and evaluating interventions on dietary intake is the existence of valid information on long-term average dietary intake in a population. Few large, population-based studies of dietary intake have been carried out in Sweden. The largest to date is the Västerbotten Intervention Program (VIP), which was initiated in 1985, with data collection still ongoing. This paper reports on the first comprehensive analyses of the dietary data and presents dietary intake patterns among over 60,000 women and men in northern Sweden during 1992–2005.

Methods

Between 1992 and 2005, 71,367 inhabitants in Västerbotten county aged 30, 40, 50, and 60 years visited their local health care center as part of the VIP. Participants of VIP filled in an 84- or 64-item food frequency questionnaire (FFQ) and provided sociodemographic information. Complete and realistic information on consumption frequency was provided by 62,531 individuals. Food intake patterns were analyzed using K-means cluster analyses.

Results

The mean daily energy intake was 6,83 (± 1,77) MJ among women and 8,71 (± 2,26) MJ among men. More than half of both women and men were classified as Low Energy Reporters (defined as individuals reporting a food intake level below the lower 95% confidence interval limit of the physical activity level). Larger variation in frequency of daily intake was seen among women than among men for most food groups. Among women, four dietary clusters were identified, labeled "Fruit and vegetables", "High fat", "Coffee and sandwich", and "Tea and ice cream". Among men, three dietary clusters were identified, labeled "Fruit and vegetables", "High fat", and "Tea, soda and cookies".

Conclusion

More distinct food intake patterns were seen among women than men in this study in northern Sweden. Due to large proportions of Low Energy Reporters, our results on dietary intake may not be suitable for comparisons with recommended intake levels. However, the results on food intake patterns should still be valid and useful as a basis for targeting interventions to groups most in need.     

Generation of discontinuous microstructures by Diamond Micro Chiseling

Diamond Micro Chiseling (DMC) is a new machining process to generate discontinuous microstructures, such as miniaturized cube corner retroreflectors or V-shaped grooves with defined endings. After a brief introduction to the process itself, this paper presents an in-depth analysis of factors that determine the achievable size and performance of such microstructures. The capability for generating discontinuous microstructures is assessed theoretically by considering the process kinematics and the diamond tool design by geometrical calculations. Thereafter, an experimental evaluation of the process is presented by showing measured data for cutting forces, achievable shape accuracy and surface finish for different structure sizes.     

Human CD22-Transgenic,Primary Murine Lymphoma Challenges Immunotherapies in Organ-Specific Tumor Microenvironments

Targeted immunotherapies have greatly changed treatment of patients with B cell malignancies. To further enhance immunotherapies, research increasingly focuses on the tumor microenvironment (TME), which differs considerably by organ site. However, immunocompetent mouse models of disease to study immunotherapies targeting human molecules within organ-specific TME are surprisingly rare. We developed a myc-driven, primary murine lymphoma model expressing a human-mouse chimeric CD22 (h/mCD22). Stable engraftment of three distinct h/mCD22⁺ lymphoma was established after subcutaneous and systemic injection. However, only systemic lymphoma showed immune infiltration that reflected human disease. In this model, myeloid cells supported lymphoma growth and showed a phenotype of myeloid-derived suppressor cells. The human CD22-targeted immunotoxin Moxetumomab was highly active against h/mCD22⁺ lymphoma and similarly reduced infiltration of bone marrow and spleen of all three models up to 90-fold while efficacy against lymphoma in lymph nodes varied substantially, highlighting relevance of organ-specific TME. As in human aggressive lymphoma, anti-PD-L1 as monotherapy was not efficient. However, anti-PD-L1 enhanced efficacy of Moxetumomab suggesting potential for future clinical application. The novel model system of h/mCD22⁺ lymphoma provides a unique platform to test targeted immunotherapies and may be amenable for other human B cell targets such as CD19 and CD20.     

Mast Cells and Basophils in the Defense against Ectoparasites: Efficient Degradation of Parasite Anticoagulants by the Connective Tissue Mast Cell Chymases

Ticks, lice, flees, mosquitos, leeches and vampire bats need to prevent the host’s blood coagulation during their feeding process. This is primarily achieved by injecting potent anticoagulant proteins. Basophils frequently accumulate at the site of tick feeding. However, this occurs only after the second encounter with the parasite involving an adaptive immune response and IgE. To study the potential role of basophils and mast cells in the defense against ticks and other ectoparasites, we produced anticoagulant proteins from three blood-feeding animals; tick, mosquito, and leech. We tested these anticoagulant proteins for their sensitivity to inactivation by a panel of hematopoietic serine proteases. The majority of the connective tissue mast cell proteases tested, originating from humans, dogs, rats, hamsters, and opossums, efficiently cleaved these anticoagulant proteins. Interestingly, the mucosal mast cell proteases that contain closely similar cleavage specificity, had little effect on these anticoagulant proteins. Ticks have been shown to produce serpins, serine protease inhibitors, upon a blood meal that efficiently inhibit the human mast cell chymase and cathepsin G, indicating that ticks have developed a strategy to inactivate these proteases. We show here that one of these tick serpins (IRS-2) shows broad activity against the majority of the mast cell chymotryptic enzymes and the neutrophil proteases from human to opossum. However, it had no effect on the mast cell tryptases or the basophil specific protease mMCP-8. The production of anticoagulants, proteases and anti-proteases by the parasite and the host presents a fascinating example of an arms race between the blood-feeding animals and the mammalian immune system with an apparent and potent role of the connective tissue mast cell chymases in the host defense.     

Prediction of plastic surface defects for 5-axis ball end milling of Ti-6Al-4 V with rounded cutting edges using a material removal simulation

The resulting surface quality after 5-axis ball end milling is of superior importance because finish milling is often the last process step determining the functional performance of a component. However, the prediction of surface topography is still a challenging task. Especially in ball end milling with the characteristic sickle shaped chip cross section, ploughing effects in the area of low chip thickness result in plastic deformation and surface defects (also known as burr). This paper provides a new approach to predict those surface defects by considering the minimum chip thickness for complex milling engagement conditions within a virtual process design. This allows the choice of suitable process parameters without extensive experimental efforts.     

Hydrodesulfurization of thiophene on carbon nanofiber supported Co/Ni/Mo catalysts

Co, Mo, NiMo and CoMo catalysts supported on alumina, fishbone and platelet carbon nanofibers (CNFs) have been prepared. The dispersion of the oxide phases was qualitatively studied and compared using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The reducibility of the catalysts was studied by temperature programmed reduction (TPR). Hydrodesulfurization (HDS) of thiophene was used as a model reaction to compare the activity of different catalysts. The activity tests showed that the alumina supported catalysts exhibited higher activity compared to the corresponding CNF supported catalysts, and the NiMo catalysts were more active than the corresponding CoMo catalysts. The thiophene HDS activity was correlated with the dispersion of the molybdenum species and the reducibility of different catalysts. Interestingly, the CNF supported Co catalysts have higher thiophene HDS activity than the CNF supported Co(Ni)Mo catalysts.