A Radiation Imaging Detector Made by Postprocessing a Standard CMOS Chip

An unpackaged microchip is used as the sensing element in a miniaturized gaseous proportional chamber. This letter reports on the fabrication and performance of a complete radiation imaging detector based on this principle. Our fabrication schemes are based on wafer-scale and chip-scale postprocessing. Compared to hybrid-assembled gaseous detectors, our microsystem shows superior alignment precision and energy resolution, and offers the capability to unambiguously reconstruct 3D radiation tracks on the spot.     

Mechanical stress evolution and the blech length: 2D simulation of early electromigration effects

Modeling of stress and electromigration at the microscopic level, in confined interconnect metallic lines with tungsten studs, can very well account for the resistance behaviour in time. The resistance change at saturation for a metallic line with blocking boundaries at both ends can be related, according to the model, to threshold product (jL)_c found by Blech [1].     

Isolation and preliminary characterization of Pichia pinus mutants insensitive to glucose repression

A new method for the isolation of glucose repression-insensitive mutants in the methylotrophic yeast Pichia pinus was developed. The method is based on screening of small suspension samples derived from 2-deoxyglucose-resistant colonies for alcohol oxidase activity. Alcohol oxidase activity was evaluated by determination of formaldehyde excreted by cells. Mutants with glucose non-repressible alcohol oxidase and catalase synthesis were obtained. All mutants grew poorly on D -xylose compared to the wild type, whereas growth on L -arabinose was similar to the wild type. Changes in the glucose transport system were suggested to be responsible for altered growth characteristics and defective glucose repression.     

Bovine muscle shortening and protein degradation after electrical stimulation, excision and chilling

Electrical stimulation-dependent improvement in beef tenderness resulted from mechanisms other than avoidance of cold shortening in excised muscle chilled at a normal rate (10°C at 10h post-stimulation). At normal chilling rate, electrical stimulation enhanced degradation of the myofibrillar proteins, alpha actinin and troponin-T, and increased the amount of a 30 000 dalton protein, as assessed by gel electrophoresis, whereas sarcomere lengths were not different from unstimulated muscle. Under slightly accelerated chilling conditions (10°C at 5 h post stimulation), electrical stimulation prevented cold shortening but the meat was more tender than, and had the same sarcomere length as, unstimulated muscle chilled to 10°C in 10 h. Electrical stimulation did not improve the tenderness of beef chilled at a rapid rate (10°C at 2 h post stimulation), nor did it prevent cold shortening when muscles were chilled rapidly.     

Moisture resistance of SU-8 and KMPR as structural material

This paper treats the moisture resistance of SU-8 and KMPR, two photoresists considered as structural material in microsystems. Our experiments focus on the moisture resistance of newly developed radiation imaging detectors containing these resists. Since these microsystems will be used unpackaged, they are susceptible to all kinds of environmental conditions. Already after 1 day of exposure to a humid condition the structural integrity and adhesion of SU-8 structures, measured by a shear test is drastically reduced. KMPR photoresist shows much stronger moisture resistance properties, making it a suitable alternative in our application.     

Profiling of the Bacterial Microbiota along the Murine Alimentary Tract

Here, the spatial distribution of the bacterial flora along the murine alimentary tract was evaluated using high throughput sequencing in wild-type and Tff3-deficient (Tff3^KO) animals. Loss of Tff3 was linked to increased dextran sodium sulfate-induced colitis. This systematic study shows the results of 13 different regions from the esophagus to the rectum. The number of bacterial species (richness) increased from the esophagus to the rectum, from 50 to 200, respectively. Additionally, the bacterial community structure changed continuously; the highest changes were between the upper/middle and lower gastrointestinal compartments when comparing adjacent regions. Lactobacillus was the major colonizer in the upper/middle gastrointestinal tract, especially in the esophagus and stomach. From the caecum, a drastic diminution of Lactobacillus occurred, while members of Lachnospiraceae significantly increased. A significant change occurred in the bacterial community between the ascending and the transverse colon with Bacteroidetes being the major colonizers with relative constant abundance until the rectum. Interestingly, wild-type and Tff3^KO animals did not show significant differences in their bacterial communities, suggesting that Tff3 is not involved in alterations of intraluminal or adhesive microbiota but is obviously important for mucosal protection, e.g., of the sensitive stem cells in the colonic crypts probably by a mucus plume.     

Catalytic effects of metals of the iron subgroup on the chlorination of titanium carbide to form nanostructural carbon

The effect of the reaction temperature and the metals of an iron subgroup on the thermo-chemical treatment of titanium carbide with a chlorine gas and their influence on the carbon structure obtained thereby was studied. Different analytical methods such as porosity measurements, X-ray diffraction spectrometry and a high-resolution electron microscopy revealed the catalytic behaviour of the above-mentioned metals, which appeared to support the formation of graphitised carbon at much lower temperatures compared to those needed for the ordinary thermo-chemical chlorination of titanium carbide.