1,173 research outputs found
Derivation of the Classical Lagrangian for the Relativistic Spinning Particle
The `classical' model for a massive spinning particle, which was recently
proposed, is derived from the isotropic rotator model. Through this derivation,
we note that the spin can be understood as the relativistic extension of the
isotropic rotator. Furthermore, the variables t_\m corresponding to the
\p^* of the `pseudo-classical' model, are necessary for the covariant
formulation. The dynamical term for these extra variables is naturally obtained
and the meaning of the constraint term p^\s\L_{\s\n}+mt_\n =0, which was
recently shown to give `quasi-supersymmetry', is clarified.Comment: 8 pages, LaTe
Genome-wide expression profiles of endogenous retroviruses in lymphoid tissues and their biological properties
AbstractEndogenous retroviruses (ERVs) constitute approximately 8–10% of the human and mouse genome. Some autoimmune diseases are attributed to the altered expression of ERVs. In this study, we examined the ERV expression profiles in lymphoid tissues and analyzed their biological properties. Tissues (spleen, thymus, and lymph nodes [axillary, inguinal, and mesenteric]) from C57BL/6J mice were analyzed for differential murine ERV (MuERV) expression by RT-PCR examination of polymorphic U3 sequences. Each tissue had a unique profile of MuERV expression. A genomic map identifying 60 putative MuERVs was established using 22 unique U3s as probes and their biological properties (primer binding site, coding potential, transcription regulatory element, tropism, recombination event, and integration age) were characterized. Interestingly, 12 putative MuERVs retained intact coding potentials for all three polypeptides essential for virus assembly and replication. We suggest that MuERV expression is differentially regulated in conjunction with the transcriptional environment of individual lymphoid tissues
Synthesis of Eu-doped (Gd,Y) 2 O 3 transparent optical ceramic scintillator
A novel process for transparent oxide ceramic scintillator with a composition of Gd 1.94-x Y x Eu 0.06 O 3 was developed. The process consists of a glycine-nitrate combustion synthesis of nano-sized starting powder and subsequent controlled sintering and annealing steps. The organic molecules remaining in the as-combusted powder were efficiently removed by the combined heat-treatment at vacuum and air atmospheres. Hot-pressed ceramic scintillators show transparent optical state and high light output. Transparent optical ceramic scintillator with a high content of Gd (up to 80 mol%) was fabricated by the process. The measured light output of Gd 1.54 Y 0.4 Eu 0.06 O 3 ceramic scintillator was about two times higher that that of CdWO 4 single crystal. In a typical radiation detection system, the scintillator plays the key role of converting the incident energy of ionizing radiation into scintillation light photons, then the emitted lights are collected by the under-laid photosensor. This specific application requires an ideal scintillator that has high light output, fast decay property, low afterglow, and so forth. Recently, a large number of new scintillator systems has been reviewed, 1 resulting, in part, with the development of a new class of scintillator: the polycrystalline ceramic scintillator
Micro multi-nozzle jet coating of organic thin film for organic light-emitting diode lighting devices
Abstract
Uniform deposition across large areas of an organic layer is one of the challenges for the industrial application of solution-based organic light‐emitting diode (OLED). In this paper, we propose an organic thin film deposition method for OLED using a micro multi-nozzle jet coating process. The developed micro multi-nozzle jet head consists of eighteen nozzles (100μm diameter), a side suction line, inlets, and a nozzle protection outer hole. To demonstrate organic thin film deposition for OLED lighting device fabrication, a poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) solution was used as a hole injection layer (HIL). Thickness uniformity of the PEDOT:PSS thin film was analyzed by regulating the jetting pressure. Through single-path coating of twelve successive stable column-jet flows, PEDOT:PSS organic film of 26mm width was coated on an ITO substrate at 1m/s head speed. The PEDOT:PSS thin film of 24.25 ± 1.55nm (CV = 6.39%) thickness was obtained by the proposed coating method. For the feasibility test, OLED lighting devices with emission areas of 20mm × 20mm and 70mm × 70mm were successfully fabricated using PEDOT:PSS films deposited by a micro multi-nozzle jet coating method
Isolated Weakness of Middle, Ring, and Little Fingers due to a Small Cortical Infarction in the Medial Precentral Gyrus
Small cortical strokes can produce predominant isolated weakness in a particular group of fingers: radial or ulnar. The traditional views are of point-to-point representations of each finger to neurons located in the precentral gyrus of the motor cortex such that the neurons of the radial fingers are located laterally and those of the ulnar fingers are located medially. We present a case of isolated weakness of middle, ring, and little fingers due to a small cortical infarction in the medial precentral gyrus
Elucidation of Akkermansia muciniphila Probiotic Traits Driven by Mucin Depletion
Akkermansia muciniphila is widely considered a next-generation beneficial microbe. This bacterium resides in the mucus layer of its host and regulates intestinal homeostasis and intestinal barrier integrity by affecting host signaling pathways. However, it remains unknown how the expression of genes encoding extracellular proteins is regulated in response to dynamic mucosal environments. In this study, we elucidated the effect of mucin on the gene expression and probiotic traits of A. muciniphila. Transcriptome analysis showed that the genes encoding most mucin-degrading enzymes were significantly upregulated in the presence of mucin. By contrast, most genes involved in glycolysis and energy metabolic pathways were upregulated under mucin-depleted conditions. Interestingly, the absence of mucin resulted in the upregulation of 79 genes encoding secreted protein candidates, including Amuc-1100 as well as members of major protein secretion systems. These transcript level changes were consistent with the fact that administration of A. muciniphila grown under mucin-depleted conditions to high-fat diet-induced diabetic mice reduced obesity and improved intestinal barrier integrity more efficiently than administration of A. muciniphila grown under mucin-containing conditions. In conclusion, mucin content in the growth medium plays a critical role in the improvement by A. muciniphila of high-fat diet-induced obesity, intestinal inflammation, and compromised intestinal barrier integrity related to a decrease in goblet cell density. Our findings suggest the depletion of animal-derived mucin in growth medium as a novel principle for the development of A. muciniphila for human therapeutics
Magnetic Resonance Imaging Compatibility of the Polymer-based Cochlear Implant
ObjectivesIn this study, we compared the magnetic resonance (MR) image artifacts caused by a conventional metal-based cochlear implant and a newly developed liquid crystal polymer (LCP)-based device.MethodsThe metal-based cochlear implant system (Nurobiosys Co.) was attached to side of the head of a subject and the LCP-based device was attached to opposite side. In both devices, alignment magnets were removed for safety. Magnetic resonance imaging (MRI) was performed on a widely used 3.0 T and an ultra-high 7.0 T MRI machine. 3.0 and 7.0 T MR images were acquired using T1- and T2*-weighted gradient echo sequences, respectively.ResultsIn the 3.0 T images, the metal-based device on the left side generated the significant amount of artifacts. The MR images in the proximity of the metal package were obscured by the artifacts in both axial and sagittal views. On the other hand, the MR images near the LCP-based device were relatively free from the artifacts and clearly showed the brain structures. 7.0 T MR images showed the more severe distortion in the both sides but the metal-based cochlear implant system caused a much larger obscure area than the LCP-based system.ConclusionThe novel LCP-based cochlear implant provides a good MRI compatibility beyond present-day cochlear implants. Thus, MR images can be obtained from the subjects even with the implanted LCP-based neural prosthetic systems providing useful diagnostic information. Furthermore, it will be also useful for functional MRI studies of the auditory perception mechanism after cochlear implantations as well as for positron emission tomography-MRI hybrid imaging
- …