Optimization of a Microfluidic Mixing Process for Gene Expression-Based Bio-dosimetry

In recent decades advances in radiation imaging and radiation therapy have led to a dramatic increase in the number of people exposed to radiation. Consequently, there is a clear need for personalized biodosimetry diagnostics in order to monitor the dose of radiation received and adapt it to each patient depending on their sensitivity to radiation exposure (Hall E.J. and Brenner D. J., 2008). Similarly, after a large-scale radiological event such as a dirty bomb attack, there will be a major need to assess, within a few days the radiation doses received by tens of thousands of individuals. Current high throughput devices can handle only a few hundred individuals per day. Hence there is a great need for a very fast self-contained non-invasive biodosimetric device based on a rapid blood test.This paper presents a case study where regression methods and designed experiments are used to arrive at the optimal settings for various factors that impact the kinetics in a biodosimetric device. We use ridge regression to initially identify a set of potentially important variables in the mixing process which is one of the critical sub systems of the device. This was followed by a series of designed experiments to arrive at the optimal setting of the significant microfluidic cartridge and piezoelectric disk (PZT) (D. Sadler, F. Zenhausern, U.S. Patent 6,986,601; Lee, S. Y., Ko, B., Yang, W., 2005) related factors. This statistical approach has been utilized to study the microfluidic mixing to mix water and dye mixtures of 70 μl volume. The outcome of the statistical design, experimentation and analysis was then exploited for optimizing the design, fabrication and assembly of the microfluidic devices. As a result of the experiments that were performed, the system was fine tuned and the mixing time was reduced from 5.5 minutes to 2 minutes.     

Erzeugung elektronischer Signaturen mittels Trusted Platform Module

Zusammenfassung  Das durch die Trusted Computing Group spezifizierte Trusted Platform Module (TPM) bietet ?hnliche Funktionen wie eine Smartcard. Der Beitrag untersucht, unter welchen Voraussetzungen das TPM für die Erzeugung von qualifizierten elektronischen Signaturen geeignet ist. Frederic Stumpf Wissenschaftlicher Mitarbeiter am Fachgebiet Sicherheit in der Informationstechnik der TU Darmstadt Markus Sacher Mitglied der Projektgruppe verfassungsvertr?gliche Technikgestaltung (provet) an der Universit?t Kassel Prof. Dr. Alexander Ro?nagel Leiter der Projektgruppe verfassungsvertr?gliche Technikgestaltung (provet) an der Universit?t Kassel Prof. Dr. Claudia Eckert Leiterin des Fraunhofer Instituts für Sichere Informations-Technologie (SIT)     

Numerical Development of ZnO/Quartz Love Wave Structure for Gas Contamination Detection

Love wave structures are encouraging devices for sensing applications in gaseous or liquid media because of their high sensitivity. In this paper, we first investigate basic properties of a ZnO/quartz Love wave device by the use of theoretical considerations in order to get a good gas sensor. Second, experimental results of the developed structure, ZnO(2.1 mum)/90deg ST-cut quartz, confirm the suitable characteristics, including temperature compensation, high electromechanical coupling coefficient, and good sensitivity to mass loading effect. We finally characterize the gas effect on the photoresist Shipley S1805 with the above structure, and thus we confirm our approach     

This time it's different: An inevitable decline in world petroleum production will keep oil product prices high,causing military conflicts and shifting wealth and power from democracies to authoritarian regimes

There is virtual agreement among geologists that world production of conventional oil will peak at some point in the future. Oil, after all, is a finite resource, while demand will only grow over time. Geologists disagree, however, exactly when the peak will occur. Using data from the International Energy Agency, the US Department of Energy, the Association for the Study of Peak Oil and Gas, and petroleum industry sources, we argue that conventional oil production will reach a worldwide maximum within the next 5–10 years, earlier than generally estimated, thus leaving a very short time frame within which to plan for conversion to alternative sources of energy. Unless planning is initiated immediately, the United States and other Western democracies will see their positions in the global economy undercut as military conflicts over limited energy resources increase, and wealth and power are shifted to authoritarian regimes in Russia, Venezuela, Africa and the Middle East.     

电子投影显示的新趋势

数字投影正以比任何其他大屏幕显示技术都快得多的速度在改进,有可能成为竞争中的优胜者,从面统治大屏幕HDTV消费类市场。但这还需要一段时间。     

从非洲土壤中分离新的产生脂肪酶的细菌

从采自非洲 (喀麦隆和加纳 )的 3 3个土样中分离得到的产生脂肪酶的细菌H 1 ,初步鉴定为假单胞菌属 .以菌株H 1为出发菌株 ,经紫外线照射和亚硝基胍处理 ,得诱变菌株H 58,其脂肪酶产生能力达 4 0U/mL .对菌株H 58进行生产能力的稳定性试验 ,结果良好 .连续传代 5次能保持良好的产脂肪性能 .     

Universal response in liquid chromatography using charged aerosol detection

A new, empirical approach is introduced to correct for the varying response of aerosol-based detectors with the varying composition of the mobile phase during gradient elution in HPLC. A Corona charged aerosol detector was used in the experiments. The detector is characterized by a nearly universal response at a given, constant mobile-phase composition for sufficiently nonvolatile analytes. A second pump was used to deliver an exactly inverse gradient compared to the analytical HPLC system, and both flows were mixed in a tee piece before introduction to the Corona detector. The approach proposed made it possible to extend the universal response from isocratic to gradient elution conditions in HPLC, vastly improving the usefulness of this detection technique. The constant response of the detector obtained in this way was first demonstrated in flow injection analysis. Very similar calibration curves were obtained for six sulfonamide drugs after mobile-phase compensation. The approach was also applied to gradient elution with excellent results. The data were characterized by good precision ranging from 4% RSD at 10 mg/L to 1.6% RSD at 780 mg/L. The average limit of detection with a 2-microL injection was 0.5 mg/L, corresponding to 1 ng injected on the column. The approach proposed allows quantification of unknown compounds, e.g., in pharmaceutical mixtures. Measurement of analytes at a relative concentration of 0.05% versus the main component is demonstrated.     

Peptides released from acid goat whey by a yeast-lactobacillus association isolated from cheese microflora

Seven lactobacilli and a variety of microflora extracted from twenty five commercial cheeses were grown on unsupplemented acid goat whey and screened for their capacity to hydrolyse whey proteins [alpha-lactalbumin (alpha-la) and beta-lactoglobulin (beta-lg)] and to generate peptides. Fermentations were performed aerobically or anaerobically at 37 degrees C using crude or pre-heated whey (10 min at 65, 75 or 85 degrees C). Under aerobic conditions, growth of lactobacilli was poor and protein hydrolysis did not occur. Anaerobic conditions slightly increased lactobacilli growth but neither beta-lg hydrolysis nor peptide generation were observed. More than 50% of alpha-la was digested into a truncated form of alpha-la (+/- 12 kDa) in crude whey and whey pre-heated at 65 degrees C. Twenty-five microflora extracted from raw milk cheeses were screened for their proteolytic activities on acid goat whey under the conditions previously described. Eight of them were able to hydrolyse up to 50% of alpha-la mainly during aerobic growth on crude or pre-heated whey. The corresponding hydrolysates were enriched in peptides. The hydrolysate involving microflora extracted from Comté cheese after or at 18 months ripening was the only one to exhibit hydrolysis of both alpha-la and beta-lg. Microbiological analysis showed that microorganisms originating from Comté cheese and capable of growth on unsupplemented whey consisted of Candida parapsilosis and Lactobacillus paracasei. Fermentation kinetic profiles suggested that peptides were released from alpha-la hydrolysis. The co-culture of both microorganisms was required for alpha-la hydrolysis that occurred concomitantly with the pH decrease. During whey fermentation, Cand. parapsilosis excrete at least one protease responsible for alpha-la hydrolysis, and Lb. paracasei is responsible for medium acidification that is required for protease activation.     

The fluorimetric FAST method, a simple tool for the optimization of microwave pasteurization of milk

The effect of microwave pasteurization of cow's milk on its nutritional quality was examined by the FAST method (Fluorescence of Advanced Maillard products and Soluble Tryptophan). Raw milk samples were submitted to different laboratory scale in batch microwave treatments using a central composite experimental design based on specific power and treatment time. The FAST index and bacterial count were monitored to assess protein denaturation, modification by the Maillard reaction and pasteurization efficiency, respectively. High discrimination between samples indicated that the FAST method is a potent tool for estimating the deterioration of the milk quality during experimental microwave treatment. Thus, the FAST index can be effectively used as the continuous response in experimental designs set up and to maximize information economically. In short, the FAST method allows us to retain the rapidity of experimental design while providing the advantages of convenience and low cost.