Analyzing the Reliability of Degradable Networks

The reachability of a strongly connected network may be destroyed after link damage,Since many networds have directed links with the potential for reversal,the reachability may be restored by reversing the direction of links.In this paper,the reliability of a network that allows reversal of links in discussed.     

Serine Protease Inhibitors as Good Predictors of Meat Tenderness: Which Are They and What Are Their Functions?

Since years, serine proteases and their inhibitors were an enigma to meat scientists. They were indeed considered to be extracellular and to play no role in postmortem muscle proteolysis. In the 1990's, we observed that protease inhibitors levels in muscles are a better predictor of meat tenderness than their target enzymes. From a practical point of view, we therefore choose to look for serine protease inhibitors rather than their target enzymes, i.e. serine proteases and the purpose of this report was to overview the findings obtained. Fractionation of a muscle crude extract by gel filtration revealed three major trypsin inhibitory fractions designed as F1 (Mr:50–70 kDa), F2 (Mr:40–60 kDa) and F3 (Mr:10–15kD) which were analyzed separately. Besides antithrombin III, an heparin dependent thrombin inhibitor, F1 and F2 comprised a large set of closely related trypsin inhibitors encoded by at least 8 genes bovSERPINA3-1 to A3-8 and able to inhibit also strongly initiator and effector caspases. They all belong to the serpin superfamily, known to form covalent complexes with their target enzymes, were located within muscle cells and found in all tissues and fluids examined irrespective of the animal species. Potential biological functions in living and postmortem muscle were proposed for all of them. In contrast to F1 and F2 which have been more extensively investigated only preliminary findings were provided for F3. Taken together, these results tend to ascertain the onset of apoptosis in postmortem muscle. However, the exact mechanisms driving the cell towards apoptosis and how apoptosis, an energy dependent process, can be completed postmortem remain still unclear.     

Fungal Infection Reduces Herbivore-Induced Plant Volatiles of Maize but does not Affect Naïve Parasitoids

Plants attacked by insects release volatile compounds that attract the herbivores' natural enemies. This so-called indirect defense is plastic and may be affected by an array of biotic and abiotic factors. We investigated the effect of fungal infection as a biotic stress agent on the emission of herbivore-induced volatiles and the possible consequences for the attraction of two parasitoid species. Maize seedlings that were simultaneously attacked by the fungus Setosphaeria turcica and larvae of Spodoptera littoralis emitted a blend of volatiles that was qualitatively similar to the blend emitted by maize that was damaged by only the herbivore, but there was a clear quantitative difference. When simultaneously challenged by fungus and herbivore, the maize plants emitted in total 47% less of the volatiles. Emissions of green leaf volatiles were unaffected. In a six-arm olfactometer, the parasitoids Cotesia marginiventris and Microplitis rufiventris responded equally well to odors of herbivore-damaged and fungus- and herbivore-damaged maize plants. Healthy and fungus-infected plants were not attractive. An additional experiment showed that the performance of S. littoralis caterpillars was not affected by the presence of the pathogen, nor was there an effect on larvae of M. rufiventris developing inside the caterpillars. Our results confirm previous indications that naïve wasps may respond primarily to the green leaf volatiles.     

Systemic distribution and elimination of plain and with Cy3.5 functionalized poly(vinyl alcohol) coated superparamagnetic maghemite nanoparticles after intraarticular injection in sheep in vivo

PVA coated and fluorescent dye (Cy3.5) functionalized vinyl alcohol/vinyl amine copolymer coated superparamagnetic iron oxide nanoparticles (SPION) were evaluated for systemic distribution and elimination after intraarticular injection in sheep. Observation was done at 3, 24, 72, and 120 hours after injection using light microscopy, fluorescent microscopy, and confocal microscopy. No pathologic influence of SPION on the tissue harvested could be seen. A significantly increased iron content could be identified in the kidneys, lymph nodes, and spleen after injection of SPION. No particles were detected in the liver, the urinary, and the gall bladder. No positive fluorescent signal could be attributed to SPION throughout the organs. Our results indicated that the iron component of the SPION is possible to be incorporated into the physiologic iron metabolism after reabsorption in the proximal tubule system of the kidney and that concentration levels of Cy3.5 are too low to be detected throughout the body.     

Light-induced in situ patterning of DNA-tagged biomolecules and nanoparticles

We present an in situ method for the selective manipulation of DNA-tagged nano-objects such as vesicles or gold colloids in aqueous solution, at neutral pH. The method makes use of the photosensitizer concept found in photodynamic therapy. Here, single-stranded DNA is immobilized onto a surface via the biotin/streptavidin linkage. If the streptavidin is fluorescently labeled, reactive species will be created during laser-induced photobleaching of the label. These reactive species can then completely or partly suppress the DNA hybridization and cause the removal of the streptavidin. The technique thereby enables a dynamic on–off control over surface density of immobilized DNA-tagged nano-objects. Furthermore, combining this in situ manipulation of DNA with prepatterning of single-stranded DNA in the micro and later in the nano range provides a means for the dynamic patterning required for applications in biosensing and nanotechnology.     

Spread of a green fluorescent protein-tagged Pseudomonas putida in a water pipe following airborne contamination

An aerosol of green fluorescent protein-tagged Pseudomonas putida, created during high-pressure water cleaning of a coupon colonized by a biofilm of the green fluorescent protein bacterium, contaminated the water supply of an experimental setup. The upward spread of P. putida in a vertical pipe of supply water was 4.3 cm/day. Results highlight that a water supply to a food plant can be contaminated by an aerosol of environmental flora, created in typical cleaning operations, and become a reoccurring source of contamination. A practical response that could be taken in a food plant is briefly discussed.     

Advanced Subcompartmentalized Microreactors: Polymer Hydrogel Carriers Encapsulating Polymer Capsules and Liposomes

The design of compartmentalized carriers for advanced drug delivery systems or artificial cells and organelles is of interest for biomedical applications. Herein, a polymer carrier microreactor that contains two different classes of subcompartments, multilayered polymer capsules and liposomes, is presented. 50 nm‐diameter liposomes and 300 nm‐diameter polymer capsules are encapsulated into a larger polymer carrier capsule, demonstrating control over the spatial positioning of the subcompartments, which are either ‘membrane‐associated’ or 'free‐floating’ in the aqueous interior. Selective and spatially dependent degradation of the 300 nm‐diameter subcompartments (without destroying the structural integrity of the enzyme‐loaded liposomes) is also shown, by performing an encapsulated enzymatic reaction using the liposomal subcompartments. These findings cover several important aspects toward the development of engineered compartmentalized carrier vessels for the creation of artificial cell mimics or advanced therapeutic delivery systems.     

Coercivity and domain structure of nanograined Fe–C alloys after high-pressure torsion

The microstructure and magnetic properties of binary hypo- and hyper-eutectoid Fe–C alloys were studied. The investigations have been carried out on the samples in the as-cast state, after a long annealing at 725 °C and on the specimens after the high-pressure torsion (HPT). The deformation was carried out at the ambient temperature and the pressure of 5 GPa. The grain size after HPT is in the nanometer range. Long annealing leads to a drastic decrease of the coercivity in comparison with the as-cast alloys. In all alloys the coercivity H _c increases with increasing carbon content. The distance L between pinning points for domain walls decreases with increasing carbon content. Increase of the coercivity and decrease of L are more pronounced below the eutectoid concentration. The coercivity of the nanostructured samples is higher than that of the as-cast alloys. Due to the pinning of domain walls by the cementite particles, the hysteresis loop in the coarse-grained alloys both in as-cast and annealed states has a narrowing near the zero magnetization.     

Physico‐chemical characterization of starches extracted from potatoes of the group Phureja

Starch was extracted from twenty‐four accessions of Group Phureja cultivated diploid potatoes, and from two commercial potato (Solanum tuberosum) varieties. Extracted starch samples were characterized and compared to industrial potato starch. Starch from Phureja generally exhibited smaller granule sizes and lower phosphorus content than starch from commercial potatoes. Amylose content and thermal properties (gelatinization temperature and enthalpy) were however in the same range for both groups. Starches from Phureja displayed very distinct pasting behavior from that of commercial potato. The former exhibited lower initial pasting viscosity but higher shear resistance. This may be related to lower starch granule size, causing lower swelling power and solubility. Iodine complexation results seem to indicate that phureja potatoes have higher proportion of amylopectin long chains. Phureja thus appears to be a promising new source of starch with specific physico‐chemical and functional properties intermediate between industrial potato and cereal starches.