Dipolar-modulated charge-doped trilayer organic semiconductor n-n heterojunction

A novel dipolar-modulated charge-doped trilayer n-n organic heterojunction with a bidirectional tunable energy band discontinuity is constructed. The rectifying mechanism of the trilayer is similar to the rectifying and inverse-rectifying characteristics from n-p and p-n junctions, respectively. Zero-bias optoelectronic behavior and persistent photoconductivity are discovered. These results show that what are viewed as technological hurdles in the development of an organic n-n heterojunction should, in fact, lead to a better approach in organic optoelectronics.     

Integrating sphere setup for the traceable measurement of absolute photoluminescence quantum yields in the near infrared

There is an increasing interest in chromophores absorbing and emitting in the near-infrared (NIR) spectral region, e.g., for applications as fluorescent reporters for optical imaging techniques and hence, in reliable methods for the characterization of their signal-relevant properties like the fluorescence quantum yield (Φ(f)) and brightness. The lack of well established Φ(f) standards for the NIR region in conjunction with the need for accurate Φ(f) measurements in transparent and scattering media encouraged us to built up an integrating sphere setup for spectrally resolved measurements of absolute fluorescence traceable to radiometric scales. Here, we present the design of this setup and its characterization and validation including an uncertainty budget for the determination of absolute Φ(f) in the visible and NIR. To provide the basis for better measurements of Φ(f) in the spectral window from ca. 600 to 1000 nm used, e.g., for optical imaging, the absolute Φ(f) of a set of NIR chromophores covering this spectral region are measured and compared to relative values obtained using rhodamine 101 as Φ(f) standard. Additionally, the absolute Φ(f) values of some red dyes that are among the most commonly used labels in the life sciences are presented as well as the absolute quantum yield of an optical probe for tumor imaging.     

Folate content in foods commonly consumed in Egypt

The folate content in some Egyptian foods was determined using RP-HPLC-FL. Trienzyme treatment was used for legumes, dienzyme treatment for cereals and starchy vegetables, and monoenzyme treatment for vegetables and fruits. The highest folate content (633 μg/100 g) was found in dried Jew’s mellow due to low water content, followed by legumes (e.g. 150 μg/100 g for chick peas) and leafy vegetables (100 μg/100 g). For other foods, folate content ranged from 10–90 μg/100 g. In all foods, the predominant folate form was 5-CH₃–H₄folate, except for dried Jew’s mellow, which contained more than 80% 10-HCO–PteGlu. Using folate data from our own analyses and food tables and food consumption data, the dietary folate intake per capita in Egypt was estimated. However, representative and validated food composition data for folate in Egyptian foods are needed for estimating and evaluating the adequacy of the population’s folate intake.     

Salmonella in raw meat and by-products from pork and beef

After campylobacteriosis, salmonellosis is the second main cause of human bacterial enteritis in Germany. Salmonella is known to colonize the gastrointestinal tract of animals without producing any clinical signs. Therefore, carcasses can become contaminated with Salmonella at the time of slaughter. During an 11-month period, a total of 4,170 raw meat samples and by-products from beef and pork, obtained from seven different slaughterhouses in Southern Germany, were screened by the VIDAS system for Salmonella in this study. Positive results were confirmed by isolation of the pathogen on selective agars. The overall percentage of Salmonella-positive samples was 1.4% by the VIDAS system and 0.7% by culture confirmation. Salmonella was detected in 1.8% of pork samples by the VIDAS system and in 1.1% of samples by culture. In beef samples the presence of Salmonella was verified in 0.6% of samples by the VIDAS system and in 0.1% by culture on selective agars. The highest contamination rates were found in porcine and bovine tongue samples. Salmonella was detected in porcine samples throughout the year, except in samples collected in July, and a slight increase was observed in the colder months. The VIDAS system was shown to be an efficient screening method for the detection of Salmonella, with the advantage of a reduced analysis time.     

ACD-Anlagen und Arbeitnehmerdatenschutz

In Call-Centern werden zur Arbeitssteuerung und Ressourcenverteilung Automatic Call Distribution (ACD)-Anlagen eingesetzt. Der Beitrag er?rtert die Zul?ssigkeit solcher Anlagen im Lichte des Arbeitnehmerdatenschutzes, begründet insbesondere das Mitbestimmungserfordernis des Betriebsrates, zeigt die Anforderungen auf, die an eine wirksame Betriebsvereinbarung zu stellen sind und stellt überlegungen zu individualvertraglichen Vereinbarungen in F?llen ohne Mitarbeitervertretung an.     

Biofeedback-based behavioral treatment for chronic tinnitus: Results of a randomized controlled trial.

Many tinnitus sufferers believe that their tinnitus has an organic basis and thus seek medical rather than psychological treatments. Tinnitus has been found to be associated with negative appraisal, dysfunctional attention shift, and heightened psychophysiological arousal, so cognitive-behavioral interventions and biofeedback are commonly suggested as treatments. This study developed and investigated the efficacy of a biofeedback-based cognitive-behavioral treatment for tinnitus. In total, 130 tinnitus patients were randomly assigned to an intervention or a wait-list control group. Treatment consisted of 12 sessions of a biofeedback-based behavioral intervention over a 3-month period. Patients in the wait-list group participated in the treatment after the intervention group had completed the treatment. Results showed clear improvements regarding tinnitus annoyance, diary ratings of loudness, and feelings of controllability. Furthermore, changes in coping cognitions as well as changes in depressive symptoms were found. Improvements were maintained over a 6-month follow-up period in which medium-to-large effect sizes were observed. The treatment developed and investigated in this study is well accepted and leads to clear and stable improvements. Through demonstration of psychophysiological interrelationships, the treatment enables patients to change their somatic illness perceptions to a more psychosomatic point of view. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Innovative Strategy for MicroRNA Delivery in Human Mesenchymal Stem Cells via Magnetic Nanoparticles

Bone marrow derived human mesenchymal stem cells (hMSCs) show promising potential in regeneration of defective tissue. Recently, gene silencing strategies using microRNAs (miR) emerged with the aim to expand the therapeutic potential of hMSCs. However, researchers are still searching for effective miR delivery methods for clinical applications. Therefore, we aimed to develop a technique to efficiently deliver miR into hMSCs with the help of a magnetic non-viral vector based on cationic polymer polyethylenimine (PEI) bound to iron oxide magnetic nanoparticles (MNP). We tested different magnetic complex compositions and determined uptake efficiency and cytotoxicity by flow cytometry. Additionally, we monitored the release, processing and functionality of delivered miR-335 with confocal laser scanning microscopy, real-time PCR and live cell imaging, respectively. On this basis, we established parameters for construction of magnetic non-viral vectors with optimized uptake efficiency (~75%) and moderate cytotoxicity in hMSCs. Furthermore, we observed a better transfection performance of magnetic complexes compared to PEI complexes 72 h after transfection. We conclude that MNP-mediated transfection provides a long term effect beneficial for successful genetic modification of stem cells. Hence, our findings may become of great importance for future in vivo applications.     

Nanosilver Mitigates Biofilm Formation via FapC Amyloidosis Inhibition

Multidrug resistance of bacteria is a major challenge due to the wide‐spread use of antibiotics. While a range of strategies have been developed in recent years, suppression of bacterial activity and virulence via their network of extracellular amyloid has rarely been explored, especially with nanomaterials. Here, silver nanoparticles and nanoclusters (AgNPs and AgNCs) capped with cationic branched polyethylenimine polymer are synthesized, and their antimicrobial potentials are determined at concentrations safe to mammalian cells. Compared with the ultrasmall AgNCs, AgNPs entail stronger binding to suppress the fibrillization of FapC, a major protein constituent of the extracellular amyloid matrix of Pseudomonas aeruginosa. Both types of nanoparticles exhibit concentration‐dependent antibiofilm and antimicrobial properties against P. aeruginosa. At concentrations of 1 × 10^?6 m or below, both the bactericidal activity of AgNCs and the antibiofilm capacity of AgNPs are associated with their structure‐mediated bio–nano interactions but not ion release. For AgNPs, specifically, their antibiofilm potency correlates with their capacity of FapC fibrillization inhibition, but not with their bactericidal activity. This study demonstrates the antimicrobial potential of safe nanotechnology through the novel route of amyloidosis inhibition.     

Polypyrenes as High‐Performance Cathode Materials for Aluminum Batteries

The pressing need for low‐cost and large‐scale stationary storage of electricity has led to a new wave of research on novel batteries made entirely of components that have high natural abundances and are easy to manufacture. One example of such an anode–electrolyte–cathode architecture comprises metallic aluminum, AlCl₃:[EMIm]Cl (1‐ethyl‐3‐methylimidazolium chloride) ionic liquid and graphite. Various forms of synthetic and natural graphite cathodes have been tested in recent years in this context. Here, a new type of compelling cathode based on inexpensive pyrene polymers is demonstrated. During charging, the condensed aromatic rings of these polymers are oxidized, which is accompanied by the uptake of aluminum tetrachloride anions (AlCl₄^?) from the chloroaluminate ionic liquid. Discharge is the fast inverse process of reduction and the release of AlCl₄^?. The electrochemical properties of the polypyrenes can be fine‐tuned by the appropriate chemical derivatization. This process is showcased here by poly(nitropyrene‐co‐pyrene), which has a storage capacity of 100 mAh g^?1, higher than the neat polypyrene (70 mAh g^?1) or crystalline pyrene (20 mAh g^?1), at a high discharge voltage (≈1.7 V), energy efficiency (≈86%), and cyclic stability (at least 1000 cycles).