Domain wall propagation in Permalloy nanowires with a thickness gradient

The domain wall nucleation and motion processes in Permalloy nanowires with a thickness gradient along the nanowire axis have been studied. Nanowires with widths, w = 250 nm to 3 um and a base thickness of t = 10 nm were fabricated by electron-beam lithography. The magnetization hysteresis loops measured on individual nanowires are compared to corresponding nanowires without a thickness gradient. The Hc vs. t/w curves of wires with and without a thickness gradient are discussed and compared to micromagnetic simulations. We find a metastability regime at values of w, where a transformation from transverse to vortex domain wall type is expected

Systemic inhibition of tumour angiogenesis by endothelial cell-based gene therapy

Angiogenesis and post-natal vasculogenesis are two processes involved in the formation of new vessels, and both are essential for tumour growth and metastases. We isolated endothelial cells from human blood mononuclear cells by selective culture. These blood outgrowth cells expressed endothelial cell markers and responded correctly to functional assays. To evaluate the potential of blood outgrowth endothelial cells (BOECs) to construct functional vessels in vivo, NOD-SCID mice were implanted with Lewis lung carcinoma cells subcutaneously (s.c.). Blood outgrowth endothelial cells were then injected through the tail vein. Initial distribution of these cells occurred throughout the lung, liver, spleen, and tumour vessels, but they were only found in the spleen, liver, and tumour tissue 48 h after injection. By day 24, they were mainly found in the tumour vasculature. Tumour vessel counts were also increased in mice receiving BOEC injections as compared to saline injections. We engineered BOECs to deliver an angiogenic inhibitor directly to tumour endothelium by transducing them with the gene for human endostatin. These cells maintained an endothelial phenotype and decreased tumour vascularisation and tumour volume in mice. We conclude that BOECs have the potential for tumour-specific delivery of cancer gene therapy

The MeerKAT telescope as a pulsar facility: System verification and early science results from MeerTime

We describe system verification tests and early science results from the pulsar processor (PTUSE) developed for the newly commissioned 64-dish SARAO MeerKAT radio telescope in South Africa. MeerKAT is a high-gain ( ) low-system temperature ( ) radio array that currently operates at 580–1 670 MHz and can produce tied-array beams suitable for pulsar observations. This paper presents results from the MeerTime Large Survey Project and commissioning tests with PTUSE. Highlights include observations of the double pulsar , pulse profiles from 34 millisecond pulsars (MSPs) from a single 2.5-h observation of the Globular cluster Terzan 5, the rotation measure of Ter5O, a 420-sigma giant pulse from the Large Magellanic Cloud pulsar PSR , and nulling identified in the slow pulsar PSR J0633–2015. One of the key design specifications for MeerKAT was absolute timing errors of less than 5 ns using their novel precise time system. Our timing of two bright MSPs confirm that MeerKAT delivers exceptional timing. PSR exhibits a jitter limit of whilst timing of PSR over almost 11 months yields an rms residual of 66 ns with only 4 min integrations. Our results confirm that the MeerKAT is an exceptional pulsar telescope. The array can be split into four separate sub-arrays to time over 1 000 pulsars per day and the future deployment of S-band (1 750–3 500 MHz) receivers will further enhance its capabilities

Polyunsaturated fatty acids as human health improvers

Tłuszcze są podstawowym, wysokoenergetycznym składnikiem żywności. Uważa się, że wysoki poziom spożycia tłuszczu, jak i niewłaściwy jego skład mogą powodować zagrożenia chorobami cywilizacyjnymi jak: otyłość, zaburzenia układu krążenia, nowotwory jelita grubego i piersi, a także osłabienie układu odpornościowego. Szczególne znaczenie ma skład kwasów tłuszczowych diety, a zwłaszcza proporcja kwasów nasyconych do jedno- i wielonienasyconych. Tłuszcze są również ważnym składnikiem strukturalnym błon komórkowych (fosfolipidy, cholesterol). Wielonienasycone niezbędne kwasy tłuszczowe (WNNKT) szeregu n-3 i n-6 nie mogą być syntetyzowane przez człowieka i muszą być dostarczane w diecie. Podstawowe z nich to kwas α-linolenowy (C 18:3) z rodziny n-3, będący prekursorem kwasu eikozapentaenowego (EPA) i dokozaheksaenowego (DHA) oraz kwas linolowy (C 18:2) n-6, prekursor kwasu arachidonowego (AA). Błony komórkowe ośrodkowego układu nerwowego i siatkówki oka funkcjonują prawidłowo dzięki podwójnej warstwie fosfolipidowej zbudowanej głównie z wielonienasyconych kwasów tłuszczowych. Dostarczenie tych kwasów, a zwłaszcza niesyntetyzowanych endogennie, decyduje o rozwoju umysłowym dzieci i prawidłowym funkcjonowaniu dorosłych. W ostatnich latach wzrosło zainteresowanie izomerami trans i cis nienasyconych kwasów tłuszczowych oraz sprzężonymi kwasami tłuszczowymi (CLA). Dąży się do wyjaśnienia mechanizmów działania na poziomie molekularnym i genetycznym oraz określenia roli tych kwasów w stymulowaniu stanu zdrowia ludzi. Badania prowadzone ze zwierzętami (zwłaszcza gryzoniami) wykazały, że CLA, a zwłaszcza izomer trans-10 i cis-12 redukowały lub zapobiegały otłuszczeniu, poprawiały oporność insulinową, inhibowały rozwój komórek rakowych i redukowały stany zapalne. Konieczne są dalsze badania, zwłaszcza dotyczące przydatności CLA dla ludzi, jako nutraceutyku, w prewencji i leczeniu chorób cywilizacyjnych.Fats are a basic, highly energetic component of food. Generally, it is believed that a high consumption level of fats alongside the improper composition of fats in a diet may cause risks of many typical civilization diseases such as: obesity, functional disorders of cardiovascular system, colorectal carcinoma, mammary cancer//breast carcinoma, as well as decreased power of the immune system. The composition of fatty acids in a daily diet is of special importance, in particular the rate between the saturated and single- and poly-unsaturated fatty acids. Lipids are also an important structural constituent of cell membrane (phospholipids, cholesterol). The n-3 and n-6 m poly-unsaturated fatty acids (EFA) are impossible to be manufactured (synthetized), thus, they must be supplied in a diet. The two basic EFAs are: an α-linolenic acid (C18:3) from the n-3 family, a precursor to eicosapentaenoic acid (EPA) and to docosahexaenoic acid (DHA), and a linoleic acid (C18:2) from the n-6 family, a precursor to arachidonic acid (AA). Cell membranes of the central neural system and of the retina function properly owing to a double layer of phospholipid molecules, and this layer consists mainly of EFAs. Therefore, human organisms must be supplied with EFAs, especially with EFAs that are not synthetised endogenicly, as they determine both the mental development of children and the proper functioning of the organisms of adults. Recently, there is a growing interest in trans- and cis-isomers of fatty acids, and in their conjugated forms (CLA). It is also attempted to explain mechanisms of their action at the molecular and genetic level, and to determine their role in stimulating the health condition of people. Experiments and research on animals (in particular with rodents) proved that CLA, especially the trans-10 & cis-12 isomers, could reduce or prevent fat deposition, improve the insulin response, inhibit the growth of cancerous cells, and reduce inflammatory processes. It is indispensable to conduct further investigation, especially for the purpose of checking the usefulness of CLA as a nutraceutic in preventing and treating contemporary civilization diseases

Evaluation of technology and technological capabilities of the company from the metal industry

W artykule przedstawiono wyniki w zakresie oceny konkurencyjności technologii i możliwości technologicznych w wybranym przedsiębiorstwie z branży metalowej. Do oceny konkurencyjności technologii wykorzystano matrycę STO, z kolei w celu oceny możliwości technologicznych zastosowano macierz 3x3. W ramach oceny konkurencyjności technologii dokonano porównania czynników wpływających na technologie w badanej firmie oraz w dwóch firmach konkurencyjnych. Analiza wykazała przewagę badanej firmy w badanym zakresie nad firmami konkurencyjnymi. Ocena możliwości technologicznych i czynników je determinujących wykazała z kolei, że przedsiębiorstwo powinno „szukać okazji”, bazując na swoim potencjale technologicznym i pozycji na rynku. Koniecznym działaniem wymagającym poprawy ze strony kadry zarządzającej przedsiębiorstwem jest system motywacyjny, który skutkuje dużą rotacją pracowników, częstym napływem nowych pracowników, co oddziałuje w efekcie na małe doświadczenie pracowników z zastaną technologią.The article presents the results in the field of assessment of technology competitiveness and technological capabilities in a selected company from the metal industry. The STO matrix was used to assess the competitiveness of the technology, while the 3x3 matrix was used to assess the technological capabilities. In order to assess the competitiveness of technology, a comparison was made between factors affecting technologies in the company under study and two competing companies. The analysis showed the studied company's advantage in this respect over competing companies. The assessment of technological capabilities and factors determining them has shown that the company should "look for opportunities" based on its technological potential and market position. Necessary action requiring improvement on the part of the company's management staff is the incentive system, which results in high employee turnover, frequent inflow of new employees, which in effect results in low experience of employees with existing technology

Analysis of elements contents in fuels and biofuels

W artykule przedstawiono znormalizowane metody oznaczania zawartości pierwiastków w paliwach i biopali-wach metodą spektrometrii emisyjnej z plazmą indukcyjnie sprzężoną (ICP-OES). Przywołane metody różnią się zakresem oznaczanych pierwiastków i zakresem oznaczanych stężeń. Omówiono podstawy metod spektroskopowych, metody przygotowania próbek do pomiaru oraz zasady spektrometrii emisyjnej. Metodę ICP-OES wykorzystano do badania zawartości pierwiastków w oleju napędowym, oleju napędowym z dodatkiem estrów metylowych wyższych kwasów tłuszczowych (FAME) oraz czystym FAME. Próbki paliw podawano bezpośrednio do analizy, natomiast próbki FAME analizowano po rozcieńczeniu w rozpuszczalniku organicznym. Przedstawiono elementy walidacji metody badawczej oraz typowe zawartości 18 pierwiastków (Al, B, Ba, Ca, Cr, Cu, Fe, K, Mg, Mo, Na, Ni, P, Si, Sn, Ti, V i Zn) w paliwach i biopaliwach.In the present paper normalised test methods for determination of elements in fuels and biofuels by means of inductively coupled plasma emission spectrometry (ICP-OES) are presented. The mentioned test methods differs in the range of elements determined and the range of their concentrations. Some basics of spectroscopic methods, sample preparation and principles of emission spectrometry are discussed. The ICP-OES method was used to investigation on elements contents in Diesel oil, Diesel oil with addition of fatty acid methyl esters (FAME) and pure FAME. Fuel samples were analysed directly, whereas FAME samples were analysed after dilution in organic solvent. Some ele-ments of method validation and a typical contents of 18 elements (Al, B, Ba, Ca, Cr, Cu, Fe, K, Mg, Mo, Na, Ni, P, Si, Sn, Ti, V and Zn) in fuels and biofuels are presented

Visual Motion Perception using Critical Branching Neural Computation

Motion processing in visual systems is supported by various subcortical and cortical microcircuits. However, all motion processing requires a basic capacity to integrate and combine information over time, as may be true for all microcircuits that support perceptual and cognitive functions. In the present study, a generic microcircuit model is presented that selftunes its recurrent spiking dynamics to its critical branching point. The model is shown to have generic memory capacity that can be tapped for the purpose of visual motion processing. These results suggest that critical branching neural networks may provide general bases for spiking models of motion processing and other perceptual and cognitive functions

Practical aspects related to application of chitin and its derivatives in wound management

Chityna jest polisacharydem o unikatowych właściwościach. W pracy zostały omówione właściwości biologiczne chityny, ograniczenia jej stosowania w przemyśle oraz kierunki modyfikacji chemicznej. Ze względu na rosnące zapotrzebowanie na nowoczesne materiały opatrunkowe, przedstawiono możliwości wykorzystania chityny i jej dwóch najbardziej popularnych pochodnych: chitozanu i dibutyrylochityny, w praktyce klinicznej oraz scharakteryzowano komercyjnie dostępne opatrunki na bazie chityny i chitozanu.Chitin is a polysaccharide with unique properties. In this paper, we reviewed biological properties of chitin, limitations of its industrial applications and directions of its further chemical modifications. In view of growing demand for the modern wound dressing materials, we discussed potential clinical applications of chitin and its two most popular derivatives: chitosan and dibutyryl chitin. In addition, we characterized commercially available chitin- and chitosan- based wound dressings