550 research outputs found
Current-driven domain wall motion in magnetic wires with asymmetric notches
Current-driven domain wall (DW) motion in magnetic wires with asymmetric
notches was investigated by means of magnetic force microscopy. It was found
that the critical current density necessary for the current-driven DW motion
depended on the propagation direction of the DW. The DW moved more easily in
the direction along which the slope of the asymmetric notch was less inclined.Comment: 11 pages, 2 figure
3D Integrated Micro-solution Plasma for The Treatment of Water - Effects of Discharge Gases -
Methylene blue molecules in aqueous solution have been decomposed by using a novel 3D integratedmicro-solution plasma reactor operated with Ar and He gases. Energy efficiency for methylene-blue decompositionin the case of Ar is relatively higher than that in the case of He. This result suggests thatcheaper Ar gas has brought about superior performance in water purification. In both cases of Ar and He,methylene-blue decomposition efficiency is one order of magnitude higher than that of conventional solutionplasma
Propagation of a magnetic domain wall in magnetic wires with asymmetric notches
The propagation of a magnetic domain wall (DW) in a submicron magnetic wire
consisting of a magnetic/nonmagnetic/magnetic trilayered structure with
asymmetric notches was investigated by utilizing the giant magnetoresistance
effect. The propagation direction of a DW was controlled by a pulsed local
magnetic field, which nucleates the DW at one of the two ends of the wire. It
was found that the depinning field of the DW from the notch depends on the
propagation direction of the DW.Comment: 12 pages, 3 figure
Directed motion of domain walls in biaxial ferromagnets under the influence of periodic external magnetic fields
Directed motion of domain walls (DWs) in a classical biaxial ferromagnet
placed under the influence of periodic unbiased external magnetic fields is
investigated. Using the symmetry approach developed in this article the
necessary conditions for the directed DW motion are found. This motion turns
out to be possible if the magnetic field is applied along the most easy axis.
The symmetry approach prohibits the directed DW motion if the magnetic field is
applied along any of the hard axes. With the help of the soliton perturbation
theory and numerical simulations, the average DW velocity as a function of
different system parameters such as damping constant, amplitude, and frequency
of the external field, is computed.Comment: Added references, corrected typos, extended introductio
Direct Comparison of Manganese Detoxification/Efflux Proteins and Molecular Characterization of ZnT10 as a Manganese Transporter
Manganese (Mn) homeostasis involves coordinated regulation of specific proteins involved in Mn influx and efflux. However, the proteins that are involved in detoxification/efflux have not been completely resolved, nor has the basis by which they select their metal substrate. Here, we compared six proteins, which were reported to be involved in Mn detoxification/efflux, by evaluating their ability to reduce Mn toxicity in chicken DT40 cells, finding that human ZnT10 (hZnT10) was the most significant contributor. A domain swapping and substitution analysis between hZnT10 and a zinc-specific transporter hZnT1 showed that residue N43, which corresponds to the His residue constituting the potential intramembranous zinc coordination site in other ZnT transporters, is necessary to impart hZnT10's unique Mn mobilization activity; residues C52 and L242 in transmembrane domains II and V play a subtler role in controlling the metal specificity of hZnT10. Interestingly, the H->N reversion mutant in hZnT1 conferred Mn transport activity and loss of zinc transport activity. These results provide important information about Mn detoxification/efflux mechanisms in vertebrate cells as well as the molecular characterization of hZnT10 as a Mn transporter
Drugs developed to treat diabetes, liraglutide and lixisenatide, cross the blood brain barrier and enhance neurogenesis
<p>Abstract</p> <p>Background</p> <p>Type 2 diabetes is a risk factor for Alzheimer's disease (AD), most likely linked to an impairment of insulin signalling in the brain. Therefore, drugs that enhance insulin signalling may have therapeutic potential for AD. Liraglutide (Victoza) and exenatide (Byetta) are novel long-lasting analogues of the GLP-1 incretin hormone and are currently available to treat diabetes. They facilitate insulin signalling via the GLP-1 receptor (GLP-1R). Numerous <it>in vitro </it>and <it>in vivo </it>studies have shown that GLP-1 analogues have a range of neuroprotective properties. GLP-1Rs are expressed in the hippocampal area of the brain an important site of adult neurogenesis and maintenance of cognition and memory formation. Therefore, if GLP-1 analogues can cross the blood brain barrier, diffuse through the brain to reach the receptors and most importantly activate them, their neuroprotective effects may be realized.</p> <p>Results</p> <p>In the present study we profiled the GLP-1 receptor agonists liraglutide (Victoza) and lixisenatide (Lyxumia). We measured the kinetics of crossing the blood brain barrier (BBB), activation of the GLP-1R by measuring cAMP levels, and physiological effects in the brain on neuronal stem cell proliferation and neurogenesis. Both drugs were able to cross the BBB. Lixisenatide crossed the BBB at all doses tested (2.5, 25, or 250 nmol/kg bw ip.) when measured 30 min post-injection and at 2.5-25 nmol/kg bw ip. 3 h post-injection. Lixisenatide also enhanced neurogenesis in the brain. Liraglutide crossed the BBB at 25 and 250 nmol/kg ip. but no increase was detectable at 2.5 nmol/kg ip. 30 min post-injection, and at 250 nmol/kg ip. at 3 h post-injection. Liraglutide and lixisenatide enhanced cAMP levels in the brain, with lixisenatide being more effective.</p> <p>Conclusions</p> <p>Our results suggest that these novel incretin analogues cross the BBB and show physiological activity and neurogenesis in the brain, which may be of use as a treatment of neurodegenerative diseases.</p
Change of tRNA identity leads to a divergent orthogonal histidyl-tRNA synthetase/tRNAHis pair
Mature tRNAHis has at its 5′-terminus an extra guanylate, designated as G−1. This is the major recognition element for histidyl-tRNA synthetase (HisRS) to permit acylation of tRNAHis with histidine. However, it was reported that tRNAHis of a subgroup of α-proteobacteria, including Caulobacter crescentus, lacks the critical G−1 residue. Here we show that recombinant C. crescentus HisRS allowed complete histidylation of a C. crescentus tRNAHis transcript (lacking G−1). The addition of G−1 did not improve aminoacylation by C. crescentus HisRS. However, mutations in the tRNAHis anticodon caused a drastic loss of in vitro histidylation, and mutations of bases A73 and U72 also reduced charging. Thus, the major recognition elements in C. crescentus tRNAHis are the anticodon, the discriminator base and U72, which are recognized by the divergent (based on sequence similarity) C. crescentus HisRS. Transplantation of these recognition elements into an Escherichia coli tRNAHis template, together with addition of base U20a, created a competent substrate for C. crescentus HisRS. These results illustrate how a conserved tRNA recognition pattern changed during evolution. The data also uncovered a divergent orthogonal HisRS/tRNAHis pair
Temperature-insensitive UV-induced Bragg gratings in silica-based planar lightwave circuits on Si
A novel technique is proposed to realise temperature-insensitive Bragg gratings in silica-based lightwave circuits on Si using a bimetal plate. A wavelength shift < 0.15nm is successfully demonstrated between -40 and 80°C in the Bragg gratings written in a Mach-Zehnder interferometer
The kinetics of neutrophils in photodynamic theraphy as anti-tumor
Photodynamic therapy (PDT) is known for its antitumor property. PDT uses a photosensitizer combined with light to kill cancer cells. Different to other non-surgical cancer treatments such as chemotherapy and radiotherapy which suppress immune system, it is suggested that PDT promotes an accumulation of neutrophils causing destruction of tumor cells; however, this is not be fully elucidated. Neutrophils is known to be a main player in the innate immunity and is closely related to the inflammation of the tumor site after PDT. Therefore, in this research, we investigated the relationship of neutrophils kinetics and anti-tumor property of PDT
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