纳米压印光刻技术--下一代批量生产的光刻技术

纳米压印光刻技术已被证实是纳米尺寸大面积结构复制的最有前途的下一代技术之一。这种速度快、成本低的方法成为生物化学、μ级流化学、μ-TAS和通信器件制造以及纳米尺寸范围内广泛应用的一种日渐重要的方法,如生物医学、纳米流体学、纳米光学应用、数据存储等领域。由于标准光刻系统的波长限制、巨大的开发工作量、以及高昂的工艺和设备成本,纳米压印光刻技术可能成为主流IC产业中一种真正富有竞争性方法。对细小到亚10nm范围内的极小复制结构,纳米压印技术没有物理极限。从几种纳米压印光刻技术中选择两种前景广阔的方法——热压印光刻(HEL)和紫外压印光刻(UV-NIL)技术给予介绍。两种技术对各种各样的材料以及全部作图的衬底大批量生产提供了快速印制。重点介绍了HEL和UV-NIL两种技术的结果。全片压印尺寸达200mm直径,图形分辨力高,拓展到纳米尺寸范围。     

TEM characterization of Si nanowires grown by CVD on Si pre-structured by nanosphere lithography

Silicon nanowires (SiNWs) were grown on Si(1 0 0) and Si(1 1 1) substrates by chemical vapour deposition (CVD) via the vapour–liquid–solid (VLS) mechanism with small gold particles used as seeds. In order to control the diameter of nanowires, their density on the substrate and their orientation we controlled the size and the distribution of Au seed particles. This was accomplished using nanosphere lithography (NSL) by which regular arrays of Au nanoparticles can be generated. This allowed us to grow single-crystalline SiNWs perpendicular to the surface of Si(1 1 1) substrates. The SiNWs and their Au caps were studied with respect to their morphology and composition using TEM, HREM and EFTEM methods. Clusters of Au are observed along the surface of SiNWs and the existence of a thin Si film on gold particles capping the SiNWs is demonstrated.     

A model to assess lactic acid bacteria aminopeptidase activities in Parmigiano Reggiano cheese during ripening

The aim of this work was to investigate in which phases of ripening of Parmigiano Reggiano cheese lactic acid bacteria aminopeptidases present in cheese extract could be involved in release of free amino acids and to better understand the behavior of these enzymes in physical-chemical conditions that are far from their optimum. In particular, we evaluated 6 different substrates to reproduce broad-specificity aminopeptidase N, broad-specificity aminopeptidase C, glutamyl aminopeptidase A, peptidase with high specificity for leucine and alanine, proline iminopeptidase, and X-prolyl dipeptidyl aminopeptidase activities releasing different N-terminal amino acids. The effects of pH, NaCl concentration, and temperature on the enzyme activities of amino acid β-naphthylamide (βNA)-substrates were determined by modulating the variables in 19 different runs of an experimental design, which allowed the building of mathematical models able to assess the effect on aminopeptidases activities over a range of values, obtained with bibliographic data, covering different environmental conditions in different zones of the cheese wheel at different aging times. The aminopeptidases tested in this work were present in cell-free Parmigiano Reggiano cheese extract after a 17-mo ripening and were active when tested in model system. The modeling approach shows that to highlight the individual and interactive effects of chemical-physical variables on enzyme activities, it is helpful to determine the true potential of an amino-peptidase in cheese. Our results evidenced that the 6 different lactic acid bacteria peptidases participate in cheese proteolysis and are induced or inhibited by the cheese production parameters that, in turn, depend on the cheese dimension. Generally, temperature and pH exerted the more relevant effects on the enzymatic activities, and in many cases, a relevant interactive effect of these variables was observed. Increasing salt concentration slowed down broad-specificity amino-peptidase C, glutamyl aminopeptidase A, proline iminopeptidase, and peptidase with high specificity for leucine and alanine. Interestingly, this variable did not affect broad-specificity aminopeptidase N and positively affected X-prolyl dipeptidyl aminopeptidase. The models elaborated varying pH, temperatures, and salt concentration and were a useful, low cost, and fast tool to understand the role of the main peptidases in the different phases of cheese ripening in relation to the major environmental factors influencing enzyme activity.     

Analysis of apoptosis during hair follicle regression (catagen)

Keratinocyte apoptosis is a central element in the regulation of hair follicle regression (catagen), yet the exact location and the control of follicular keratinocyte apoptosis remain obscure. To generate an "apoptomap" of the hair follicle, we have studied selected apoptosis-associated parameters in the C57BL/6 mouse model for hair research during normal and pharmacologically manipulated, pathological catagen development. As assessed by terminal deoxynucleotide transferase dUTP fluorescein nick end-labeling (TUNEL) stain, apoptotic cells not only appeared in the regressing proximal follicle epithelium but, surprisingly, were also seen in the central inner root sheath, in the bulge/isthmus region, and in the secondary germ, but never in the dermal papilla. These apoptosis hot spots during catagen development correlated largely with a down-regulation of the Bcl-2/Bax ratio but only poorly with the expression patterns of interleukin-1beta converting enzyme, p55TNFR, and Fas/Apo-1 immunoreactivity. Instead, a higher correlation was found with p75NTR expression. During cyclophosphamide-induced follicle dystrophy and alopecia, massive keratinocyte apoptosis occurred in the entire proximal hair bulb, except in the dermal papilla, despite a strong up-regulation of Bax and p75NTR immunoreactivity. Selected receptors of the tumor necrosis factor/nerve growth factor family and members of the Bcl-2 family may also play a key role in the control of follicular keratinocyte apoptosis in situ.     

Influence of Data Clouds Fusion From 3D Real-Time Vision System on Robotic Group Dead Reckoning in Unknown Terrain

This paper proposes the solution of tasks set required for autonomous robotic group behavior optimization during the mission on a distributed area in a cluttered hazardous terrain.The navigation scheme uses the benefits of the original real-time technical vision system(TVS)based on a dynamic triangulation principle.The method uses TVS output data with fuzzy logic rules processing for resolution stabilization.Based on previous researches,the dynamic communication network model is modified to implement the propagation of information with a feedback method for more stable data exchange inside the robotic group.According to the comparative analysis of approximation methods,in this paper authors are proposing to use two-steps post-processing path planning aiming to get a smooth and energy-saving trajectory.The article provides a wide range of studies and computational experiment results for different scenarios for evaluation of common cloud point influence on robotic motion planning.     

Accelerated visualization of selected intracranial arteries by cycled super-selective arterial spin labeling

Objective

To accelerate super-selective arterial spin labeling (ASL) angiography by using a single control condition denoted as cycled super-selective arterial spin labeling.

Materials and methods

A single non-selective control image is acquired that is shared by selective label images. Artery-selective imaging is possible by geometrically changing the position of the labeling focus to more than one artery of interest during measurement. The presented approach is compared to conventional super-selective imaging in terms of its labeling efficiency inside and outside the labeling focus using numerical simulations and in vivo measurements. Additionally, the signal-to-noise ratios of the images are compared to non-selective ASL angiography and analyzed using a two-way ANOVA test and calculating the Pearson’s correlation coefficients.

Results

The results indicate that the labeling efficiency is not reduced within the labeled artery, but can increase as a function of distance to the artery of interest when compared to conventional super-selective ASL. In the final images, no statistically significant difference of image quality can be observed while the acquisition duration could be reduced when the major brain feeding arteries are being tagged.

Conclusion

Using super-selective arterial spin labeling, a single non-selective control acquisition suffices for reconstructing selective angiograms of the cerebral vasculature, thereby accelerating image acquisition of the major intracranial arteries without notable loss of information.

     

Innovative magnesiumgerechte Gießtechnik

Innovative Magnesium adepted Casting Technology A main reason for the relatively small use of magnesium alloys as construction material is the demanding casting technology. The reactivity with ambient atmosphere and several other materials, the low specific heat values like heat capacity and heat of fusion, the small melting range and comparatively high liquidus temperatures of alloys with improved properties demand the optimizing of excisting and development new casting processes. In the scope of the Thrust Research Program SFB 390 “Magnesium Technology” founded by the German Research Council (DFG) the project B10 “Casting Technology” is engaged in the development and optimisation of casting techniques for Mg‐alloys. The emphasis of the developments in the Institute of Materials Science (IW) of the Universtity of Hanover is set on reliable, low contaminated processes of melting, melt handling and mould filling for the production of low defect structural components, even dealing with alloys difficult to handle.     

The L513S polymorphism in medium-chain acyl-CoA synthetase 2 (MACS2) is associated with risk factors of the metabolic syndrome in a Caucasian study population

Enzymes of the medium-chain acyl-CoA synthetase (MACS) family catalyze the ligation of medium chain fatty acids with CoA to produce medium-chain-acyl-CoA. At least four members of the MACS gene family are clustered on human chromosome 16p12. Association studies in the Japanese Suita cohort of MACS polymorphisms and various phenotypes revealed the contribution of the Leu513Ser polymorphism in MACS2 to multiple risk factors of the metabolic syndrome. Here, we investigated the association between this polymorphism and different risk factors in the Caucasian Metabolic Intervention Cohort Kiel. Seven hundred and sixteen male subjects aged 45-65 years were recruited for a standard oral glucose tolerance test and the postprandial assessment of metabolic parameters after an oral metabolic tolerance test (oMTT; 1017 kcal, 51.6% fat, 29.6% carbohydrates, 11.9% protein). The MACS2 Leu513Ser polymorphism was determined by TaqMan-Assay in 705 subjects. Postprandial triglyceride levels following oMTT [area under the curve (AUC)] were significantly higher in subjects carrying the Ser allele compared to subjects homozygous for the Leu allele (1690 +/- 100 mg x h/dL versus 1514 +/- 39 mg x h/dL, p = 0.04). Significant differences between genotype groups were also found for fasting (108 +/- 1.9 mg/dL versus 104 +/- 0.66 mg/dL, p = 0.04) and postprandial (AUC 535 +/- 11 versus 512 +/- 4.0, p = 0.02) glucose levels as well as for high-density-lipoprotein, body mass index, waist circumference, systolic and diastolic blood pressure. Carriers of the Ser allele also show an increased risk of impaired glucose metabolism (OR: 1.48, 95% confidence interval: 0.98-2.27, p = 0.07), adiposity (1.8, 1.16-2.81, p = 0.01) and hypertension (1.5, 0.99-2.17, p = 0.06). In conclusion, our results suggest an involvement of the MACS2 Leu513Ser polymorphism in the development of the metabolic syndrome in Caucasian population. Additionally, the higher triglyceride and glucose levels after an oMTT support a possible functional impact of the polymorphism in vivo.