Mechanical and energy examination of different agripellets

As an indirect consequence of climate change, the reduction of carbon dioxide emissions, the energy utilization of agricultural by-products will be increasingly emphasized in the future. Hungary has a large potential of agricultural residues of which is a big part could be used for energy purposes. Common feature of this by-products is that thay are originally difficult to handle and they have a small bulk density. Pellet production is one possible way to utilization, however the high ash content and low ash melting point cause problems in pellet burner equipments. Mixtures of different plant residues (wheat straw, rape seed stem, sunflower husk) and agripellets have different energetic and mechanical properties. Besides high ash content and low ash softening temperature, mechanical properties can also significantly affect the quality of pellets as well as the efficiency of firing. There were also significant differences in diameter, length, bulk density and mechanical durability of pellets

Mechanical and energy examination of different agripellets

As an indirect consequence of climate change, the reduction of carbon dioxide emissions, the energy utilization of agricultural by-products will be increasingly emphasized in the future. Hungary has a large potential of agricultural residues of which is a big part could be used for energy purposes. Common feature of this by-products is that thay are originally difficult to handle and they have a small bulk density. Pellet production is one possible way to utilization, however the high ash content and low ash melting point cause problems in pellet burner equipments. Mixtures of different plant residues (wheat straw, rape seed stem, sunflower husk) and agripellets have different energetic and mechanical properties. Besides high ash content and low ash softening temperature, mechanical properties can also significantly affect the quality of pellets as well as the efficiency of firing. There were also significant differences in diameter, length, bulk density and mechanical durability of pellets

Chemomechanical preparation by hand instrumentation and by Mtwo engine-driven rotary files, an ex vivo study

Objective: To compare the disinfecting efficacy of the sodium hypochlorite irrigation by root canal preparation with stainless steel hand files, taper 0.02 and nickel-titanium Mtwo files with taper 0.04-0.06. Study design: 40 extracted human teeth were sterilized, and then inoculated with Enterococcus faecalis (ATCC 29212). After 6 day incubation time the root canals were prepared by hand with K-files (n=20) and by engine-driven Mtwo files (VDW, Munich, Germany) (n=20). Irrigation was carried out with 2.5% NaOCl in both cases. Samples were taken and determined in colony forming units (CFU) from the root canals before and after the preparation with instruments #25 and #35. Results: Significant reduction in bacterial count was determined after filing at both groups. The number of bacteria kept on decreasing with the extension of apical preparation diameter. There was no significant difference between the preparation sizes in the bacterial counts after hand or engine-driven instrumentation at the same apical size. Statistical analysis was carried out with Mann-Whitney test, paired t-test and independent sample t-test. Conclusions: Significant reduction in CFU was achieved after the root canal preparation completed with 2.5% NaOCl irrigation, both with stainless steel hand or nickel-titanium rotary files. The root canal remained slightly infected after chemo mechanical preparation in both groups

Research in the mechanization of black locust renewal and planting

Nowadays, the black locust (Robinia pseudoacacia) is the most current and the most widely used tree species in Hungary. Due to its penetration and the wide variety of application it’s worth to examine the different mechanization options of the reforestation technologies and their costs. We provided our research in the area of Nyírerdő Nyírségi Erdészeti Zrt. According to the tests it can be said, that the cost of the reforestations with root ripping is the most favourable and the reforestation or  regeneration with planting costs the most. The disadvantage of the regeneration with root ripping is, that after its multiple application it can be observed the significantly degradation of the assortment composition and of the tree utilization income

What have we learned from two-pore potassium channels? Their molecular configuration and function in the human heart

Two-pore domain potassium channels (K2P) control excitability, stabilize the resting membrane potential below firing threshold, and accelerate repolarisation in different cells. Until now, fifteen different genes for the six K2P channel subfamily were cloned. The pore-forming part is translated from two genes and they are built up from a dimer of two two-unit transmembrane domains functioning with a wide spectrum of physiological profiles. K2P ion channels were discovered in the last two decades and gave novel opportunity to recognize the complex molecular mechanism of the potassium ion flux, and may lead to the design of individual drug targeting in the future. In this review, we summarise the structure, function, channelopathies and pharmacological silhouette of the two-pore potassium channels in the human tissues. In addition, we present the computer model of the partially reconstructed wild type K2P1/TWIK1 lacking the intracellular C and N terminal loop

Antagonism between Bacteriostatic and Bactericidal Antibiotics Is Prevalent

Combination therapy is rarely used to counter the evolution of resistance in bacterial infections. Expansion of the use of combination therapy requires knowledge of how drugs interact at inhibitory concentrations. More than 50 years ago, it was noted that, if bactericidal drugs are most potent with actively dividing cells, then the inhibition of growth induced by a bacteriostatic drug should result in an overall reduction of efficacy when the drug is used in combination with a bactericidal drug. Our goal here was to investigate this hypothesis systematically. We first constructed time-kill curves using five different antibiotics at clinically relevant concentrations, and we observed antagonism between bactericidal and bacteriostatic drugs. We extended our investigation by performing a screen of pairwise combinations of 21 different antibiotics at subinhibitory concentrations, and we found that strong antagonistic interactions were enriched significantly among combinations of bacteriostatic and bactericidal drugs. Finally, since our hypothesis relies on phenotypic effects produced by different drug classes, we recreated these experiments in a microfluidic device and performed time-lapse microscopy to directly observe and quantify the growth and division of individual cells with controlled antibiotic concentrations. While our single-cell observations supported the antagonism between bacteriostatic and bactericidal drugs, they revealed an unexpected variety of cellular responses to antagonistic drug combinations, suggesting that multiple mechanisms underlie the interactions