The Instrument Set for Generating Fast Adiabatic Passage

The design and construction of a high-performance, low-cost, and easy to assemble adiabatic extension set for homebuilt and commercial spectrometers is described. Described apparatus set was designed for the fast adiabatic passage generation and is based on direct digital synthesizer DDS. This solution gives generator high signal to noise ratio, phase stability even during frequency change which is only possible in expansive commercial high-end hardware. Critical synchronization and timing issues are considered and solutions are discussed. Different experimental conditions and techniques for the measurements are briefly discussed. The proposed system is very flexible and might be used for the measurement of low-frequency nuclear magnetic resonance

UV cross-linked polyvinylpyrrolidone electrospun fibres as antibacterial surfaces

Many bacteria become progressively more resistant to antibiotics and it remains a challenging task to control their overall levels. Polymers combined with active biomolecules come to the forefront for the design of antibacterial materials that can address this encounter. In this work, we investigated the photo-crosslinking approach of UV-sensitive benzophenone molecule (BP) with polyvinylpyrrolidone (PVP) polymer within electrospun fibres. The BP and PVP solutions allowed fabricating polymer mats that were subsequently functionalised with antibacterial lysozyme. The physical properties of the crosslinked electrospun fibres were investigated by scanning electron microscopy and atomic force microscopy. The average diameter of the obtained fibres decreased from 290 ± 50 nm to 270 ± 70 nm upon the addition of the crosslinking molecules and then to 240 ± 80 nm and 180 ± 90 nm after subsequent crosslinking reaction at an increasing time: 3 and 5 h, respectively. The peak force quantitative nanomechanical mapping (PF-QNM) indicated the increase of DMT modulus of obtained cross-linked fibres from 4.1 ± 0.8 GPa to 7.2 ± 0.5 GPa. Furthermore, the successful crosslinking reaction of PVP and BP solution into hydrogels was investigated in terms of examining photo-crosslinking mechanism and was confirmed by rheology, Raman, Fourier transform infrared and nuclear magnetic resonance. Finally, lysozyme was successfully encapsulated within cross-linked PVP-BP hydrogels and these were successfully electrospun into mats which were found to be as effective antibacterial agents as pure lysozyme molecules. The dissolution rate of photo cross-linked PVP mats was observed to increase in comparison to pure PVP electrospun mats which opened a potential route for their use as antibacterial, on-demand, dissolvable coatings for various biomedical applications

Multilayered vacuum-arc nanocomposite TiN/ZrN coatings before and after annealing: Structure, properties, first-principles calculations

Nanoscale multilayered TiN/ZrN films were deposited using sequential vacuum-arc deposition of Ti and Zr targets in a nitrogen atmosphere. Studies of film's properties were carried out using various modern methods of analysis, such as XRD, STEM, HRTEM, SIMS combined with results of nanoindentation and tribological tests. To interpret the mechanical properties of the deposited multilayer films first-principles calculations of TiN(111), ZrN(111) structures and TiN(111)/ZrN(111) multilayer were carried out. To study the influence of thermal annealing, several samples were annealed in air at the temperature 700 °C. All deposited samples were highly polycrystalline with quite large 20–25 nm crystals. The crystalline planes were very ordinated and demonstrated an excellent coordinated growth. The nanohardness and elastic modulus of non-annealed coatings reached 42 GPa and 348 GPa, respectively. Annealing in air at the temperature 700 °C led to partial oxidation of the multilayered coatings, however hardness of the non-oxidized part of the coatings remained as high, as for initial coatings. All deposited coatings demonstrate good wear resistance

Multilayered vacuum-arc nanocomposite TiN/ZrN coatings before and after annealing: Structure, properties, first-principles calculations

Nanoscale multilayered TiN/ZrN films were deposited using sequential vacuum-arc deposition of Ti and Zr targets in a nitrogen atmosphere. Studies of film's properties were carried out using various modern methods of analysis, such as XRD, STEM, HRTEM, SIMS combined with results of nanoindentation and tribological tests. To interpret the mechanical properties of the deposited multilayer films first-principles calculations of TiN(111), ZrN(111) structures and TiN(111)/ZrN(111) multilayer were carried out. To study the influence of thermal annealing, several samples were annealed in air at the temperature 700 °C. All deposited samples were highly polycrystalline with quite large 20–25 nm crystals. The crystalline planes were very ordinated and demonstrated an excellent coordinated growth. The nanohardness and elastic modulus of non-annealed coatings reached 42 GPa and 348 GPa, respectively. Annealing in air at the temperature 700 °C led to partial oxidation of the multilayered coatings, however hardness of the non-oxidized part of the coatings remained as high, as for initial coatings. All deposited coatings demonstrate good wear resistance

C9orf72 Expansion Disrupts ATM-mediated Chromosomal Break Repair

A hexanucleotide repeat expansion represents the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia, though the mechanisms by which the expansion cause neurodegeneration are poorly understood. We report elevated levels of DNA/RNA hybrids (R-loops) and double-strand breaks (DSBs) in rodent neurons, human cells, and in C9orf72-ALS patient spinal cord tissues. Accumulation of endogenous DNA damage is concomitant with defective ATM-mediated DNA repair signalling and accumulation of protein-linked DNA breaks. We further reveal that defective ATM-mediated DNA repair is a consequence of p62 accumulation, which impairs H2A ubiquitylation and perturbs ATM signalling. Adeno-associated virus- mediated expression of C9orf72-related RNA and dipeptide repeats in the murine central nervous system causes elevated DSBs, ATM defects, and triggers neurodegeneration. These findings identify R-Loops, DSBs, and defective ATM-mediated repair as pathological consequences of C9orf72 expansions, and suggest that C9orf72-linked neurodegeneration is driven, at least in part, by genomic instability

Symulacja prognostyczna chwilowej dawki cieczy aplikowanej przez opryskiwacz polowy z automatyczną regulację ciśnienia

The article presents the results of prognostic simulation which refers to the momentary dose of liquid applied by the field sprayer with an automatic pressure control. The simulation used, registered at frequency of 1 Hz, data regarding speed, the direction of movement and the position coordinates of the sprayer during the process of plant protection on field. Based on the results, it was found that while ride parallel along the straight technological paths about half of the surface of the field is covered with a liquid in an amount different from the intended at least ± 5%; and, furthermore, that should be strictly avoided to twist during working passes, because the momentary liquid dose may even exceed many times the manufacturers' recommendations of pesticides and liquid fertilizers.W artykule przedstawiono wyniki symulacji prognostycznej dotyczącej chwilowej dawki cieczy aplikowanej przez opryskiwacz polowy wyposażony w automatyczny układ regulacji ciśnienia. W symulacji wykorzystano zarejestrowane z częstotliwością 1 Hz dane dotyczące prędkości, kierunku ruchu oraz współrzędnych położenia opryskiwacza podczas procesu ochrony roślin na polu. Na podstawie uzyskanych rezultatów stwierdzono, że podczas przejazdów równoległych wzdłuż prostoliniowych ścieżek technologicznych około połowy powierzchni pola zostaje pokryte cieczą w ilości różniącej się od zamierzonej o co najmniej ±5%, a ponadto, że należy rygorystycznie unikać przejazdów roboczych podczas skrótów, gdyż chwilowe dawki cieczy mogą nawet wielokrotnie przekraczać zalecenia producentów środków ochrony roślin i nawozów płynnych

Symulacja prognostyczna chwilowej dawki cieczy aplikowanej przez opryskiwacz polowy bez układu automatycznej regulacji ciśnienia

The article presents the results of prognostic simulation which refers to the momentary dose of liquid applied by the field sprayer without the automatic pressure control. The data registered at frequency of 1 Hz, related to the speed, the direction of movement and the position coordinates of the sprayer during the process of desiccation of the winter rape were used in the simulation. Based on the results, it was found that during application of chemical protection treatment using a field sprayer without automatic pressure control it is problematic to maintain a constant operating speed and the direction of movement, and as a consequence- entails the coverage of only 25% of the field surface.W artykule przedstawiono wyniki symulacji prognostycznej dotyczącej chwilowej dawki cieczy aplikowanej przez opryskiwacz polowy bez automatycznej regulacji ciśnienia. W symulacji wykorzystano zarejestrowane z częstotliwością 1 Hz dane dotyczące prędkości, kierunku ruchu oraz współrzędnych położenia opryskiwacza podczas desykacji rzepaku ozimego. Na podstawie uzyskanych danych stwierdzono, że podczas wykonywania zabiegu ochrony chemicznej z wykorzystaniem opryskiwacza bez automatycznej regulacji ciśnienia, utrzymanie stałej prędkości roboczej oraz kierunku ruchu jest problematyczne, a rezultatem tego jest pokrycie jedynie 25% powierzchni pola założona ilością cieczy

Comparison of the selected errors of an agricultural aggregate crossings driven manually and automatically

W artykule porównane zostały dwa systemy prowadzenia ciągnika rolniczego. Pierwszy z nich, tradycyjny sposób prowadzenia agregatu ciągnikowego, polegający na aktywnej kontroli toru jazdy przez operatora. System automatyczny wykorzystywał nawigację satelitarną i był wyposażony w układ automatycznego prowadzenia pojazdu po polu. Badania zostały przeprowadzone w gospodarstwie rolnym położonym w województwie zachodniopomorskim w kwietniu i maju 2012 roku. Celem pracy było porównanie manualnego oraz automatycznego systemu prowadzenia ciągnika rolniczego pod względem odchyleń odległości od pożądanego toru jazdy po polu oraz pól powierzchni nakładek i omijaków. Na podstawie przeprowadzonych badań stwierdzono, że system automatycznego prowadzenia ciągnika wykorzystujący nawigację satelitarną był dokładniejszy i pozwolił ograniczyć powierzchnię nieobrobioną do 0,20%, zaś dwukrotnie obrobioną do 0,21% powierzchni pola.Two systems of steering a tractor were compared in the article. The first of them, a traditionalway of driving a tractor, consisting in an active control of the track by an operator. An automatic system used a satellite navigation and was equipped with automatic driving system of a vehicle on a field. The research was carried out in an agricultural farm located in Zachodniopomorksie province in April and May 2012. The objective of the paper was to compare a manual and an automatic system of steering a farm tractor on account of distance deviation from a desired track and surface areas of overlaps and underlaps. On the basis of the research which was carried out, it was determined that the system of automatic steering of a tractor which uses a satellite navigation was more accurate and allowed to limit the undone area to 0.20% and to double the area which was worked twice to 0.21% of the field area