Synchrotron x-ray topographic and high-resolution diffraction analysis of mask-induced strain in epitaxial laterally overgrown GaAs layers

Synchrotron x-ray back reflection section topographs of epitaxial lateral overgrown (ELO) GaAs samples grown on (001) GaAs substrates show images of the GaAs layers bent due to the interaction between the layer and the SiO2 mask. The topographs are simulated under the assumption of orientational contrast. Using the same data the measured x-ray diffraction curve is simulated. The calculations, which are in good agreement with the measurements, are used to gain information on the tilted (001) lattice planes in each ELO layer. We show that the bending of ELO lattice planes reaches a maximum at the center of the ELO stripes, where misorientation is at a minimum, and decreases towards the edges of the stripes, where misorientation reaches a maximum

Edible films based on milk proteins release effectively active immunoglobulins

Objectives: The goal of this study was to develop novel compositions of edible protein coatings based on immunoglobulin (Ig) fraction from bovine milk. Protein coatings can be used to protect foods against microbial, chemical, and physical damage. We developed novel compositions of edible protein coatings based on immunoglobulin (Ig) fraction from bovine milk. A lot of Ig could be obtained from under-utilized side streams of dairy industry. To the best of our knowledge, such use of the Ig fraction has not been published earlier.Materials and Methods: Bovine colostral Ig's were incorporated in edible films based on various milk proteins and investigated the characteristics of the films including solubility of Ig's and nisin and on technological properties of films. Ig's specific to cariogenic bacteria Streptococcus mutans and Streptococcus sobrinus were produced to colostrums by hyperimmunizing cows before parturition.Results: The milk Ig rich fraction suited well as a component of milk protein films. The Ig's dissolved from the films very rapidly. Nisin, commoly used for food protection, was used as a model of antimicrobial peptide. Nisin was released biologically active from both beta-lactoglobulin (beta-lg) and beta-lg/Ig films. Nisin exerted its bactericidal effect at clearly lower concentrations in the beta-lg/Ig films when compared with beta-lg film. Nisin also retained its activity better in film containing Ig-enriched whey. Incorporating Ig-enriched whey into films enhanced adhesion and tensile strength of the films. The Ig-enriched whey also affected strongly on the appearance of films based on commercial whey protein concentrate in a dose-dependent way by making the films more smooth, transparent, and clear which are all favoured properties in most food and pharmaceutical applications.Conclusions: Biologically active Ig's can be successfully incorporated in and released from milk protein based edible films. The content of Igs in films affected considerably technological properties of these films. Composition of other proteins in films had effect on preservability and release of Igs.</div

Suomen maatalous ja maaseutuelinkeinot 1998

vokMTT Taloustutkimus (MTTL

Suomen maatalous ja maaseutuelinkeinot 1999/2000

vokMTT

Vertical-external-cavity surface-emitting lasers and quantum dot lasers

The use of cavity to manipulate photon emission of quantum dots (QDs) has been opening unprecedented opportunities for realizing quantum functional nanophotonic devices and also quantum information devices. In particular, in the field of semiconductor lasers, QDs were introduced as a superior alternative to quantum wells to suppress the temperature dependence of the threshold current in vertical-external-cavity surface-emitting lasers (VECSELs). In this work, a review of properties and development of semiconductor VECSEL devices and QD laser devices is given. Based on the features of VECSEL devices, the main emphasis is put on the recent development of technological approach on semiconductor QD VECSELs. Then, from the viewpoint of both single QD nanolaser and cavity quantum electrodynamics (QED), a single-QD-cavity system resulting from the strong coupling of QD cavity is presented. A difference of this review from the other existing works on semiconductor VECSEL devices is that we will cover both the fundamental aspects and technological approaches of QD VECSEL devices. And lastly, the presented review here has provided a deep insight into useful guideline for the development of QD VECSEL technology and future quantum functional nanophotonic devices and monolithic photonic integrated circuits (MPhICs).Comment: 21 pages, 4 figures. arXiv admin note: text overlap with arXiv:0904.369

Rapid-acting antidepressants and the regulation of TrkB neurotrophic signalling-Insights from ketamine, nitrous oxide, seizures and anaesthesia

Increased glutamatergic neurotransmission and synaptic plasticity in the prefrontal cortex have been associated with the rapid antidepressant effects of ketamine. Activation of BDNF (brain-derived neurotrophic factor) receptor TrkB is considered a key molecular event for antidepressant-induced functional and structural synaptic plasticity. Several mechanisms have been proposed to underlie ketamine's effects on TrkB, but much remains unclear. Notably, preliminary studies suggest that besides ketamine, nitrous oxide (N2O) can rapidly alleviate depressive symptoms. We have shown nitrous oxide to evoke TrkB signalling preferentially after the acute pharmacological effects have dissipated (ie after receptor disengagement), when slow delta frequency electroencephalogram (EEG) activity is up-regulated. Our findings also demonstrate that various anaesthetics and sedatives activate TrkB signalling, further highlighting the complex mechanisms underlying TrkB activation. We hypothesize that rapid-acting antidepressants share the ability to regulate TrkB signalling during homeostatically evoked slow-wave activity and that this mechanism is important for sustained antidepressant effects. Our observations urge the examination of rapid and sustained antidepressant effects beyond conventional receptor pharmacology by focusing on brain physiology and temporally distributed signalling patterns spanning both wake and sleep. Potential implications of this approach for the improvement of current therapies and discovery of novel antidepressants are discussed.Peer reviewe

Overview of Toroidal and Poloidal Momentum Transport Studies in JET

Abstract. This paper reports on the recent studies of toroidal and poloidal momentum transport in JET. The ratio of the global energy confinement time to the momentum confinement is found to be close to τ E /τ φ =1 except for the low density discharges where the ratio is τ E /τ φ =2-3. On the other hand, local transport analysis of tens of discharges shows that the ratio of the local effective momentum diffusivity to the ion heat diffusivity is χ φ /χ i 0.1-0.4 rather than unity, as expected from the global confinement times and used in ITER predictions. The apparent discrepancy in the global and local momentum versus ion heat transport is explained by the fact that momentum confinement within edge pedestal is worse than that of the ion heat and thus, momentum pedestal is weaker than that of ion temperature. Another observation is that while the T i has a threshold in R/L Ti and profiles are stiff, the gradient in v φ increases with increasing torque and no threshold is found. Predictive transport simulations also confirm that χ φ /χ i 0.1-0.4 reproduce the core toroidal velocity profiles well. Concerning poloidal velocities on JET, the experimental measurements show that the carbon poloidal velocity can be an order of magnitude above the neo-classical estimate within the ITB. This significantly affects the calculated radial electric field and therefore, the E×B flow shear used for example in transport simulations. The Weiland model reproduces the onset, location and strength of the ITB well when the experimental poloidal rotation is used while it does not predict an ITB using the neo-classical poloidal velocity. The most plausible explanation for the generation of the anomalous poloidal velocity is the turbulence driven flow through the Reynold&apos;s stress. Both TRB and CUTIE turbulence codes show the existence of an anomalous poloidal velocity, being significantly larger than the neo-classical values. And similarly to experiments, the poloidal velocity profiles peak in the vicinity of the ITB and is caused by flow due to the Reynold&apos;s stress

Novel transcripts reveal a complex structure of the human TRKA gene and imply the presence of multiple protein isoforms

Publisher Copyright: © 2015 Luberg et al.Background: Tropomyosin-related kinase A (TRKA) is a nerve growth factor (NGF) receptor that belongs to the tyrosine kinase receptor family. It is critical for the correct development of many types of neurons including pain-mediating sensory neurons and also controls proliferation, differentiation and survival of many neuronal and non-neuronal cells. TRKA (also known as NTRK1) gene is a target of alternative splicing which can result in several different protein isoforms. Presently, three human isoforms (TRKAI, TRKAII and TRKAIII) and two rat isoforms (TRKA L0 and TRKA L1) have been described. Results: We show here that human TRKA gene is overlapped by two genes and spans 67 kb-almost three times the size that has been previously described. Numerous transcription initiation sites from eight different 5' exons and a sophisticated splicing pattern among exons encoding the extracellular part of TRKA receptor indicate that there might be a large variety of alternative protein isoforms. TrkA genes in rat and mouse appear to be considerably shorter, are not overlapped by other genes and display more straightforward splicing patterns. We describe the expression profile of alternatively spliced TRKA transcripts in different tissues of human, rat and mouse, as well as analyze putative endogenous TRKA protein isoforms in human SH-SY5Y and rat PC12 cells. We also characterize a selection of novel putative protein isoforms by portraying their phosphorylation, glycosylation and intracellular localization patterns. Our findings show that an isoform comprising mainly of TRKA kinase domain is capable of entering the nucleus. Conclusions: Results obtained in this study refer to the existence of a multitude of TRKA mRNA and protein isoforms, with some putative proteins possessing very distinct properties.publishersversionPeer reviewe