Functional significance of central D1 receptors in cognition: beyond working memory

The role of dopamine D1 receptors in prefrontal cortex function, including working memory, is well acknowledged. However, relatively little is known about their role in other cognitive or emotional functions. We measured both D1 and D2 receptors in the brain using positron emission tomography in healthy subjects, with the aim of elucidating how regional D1 and D2 receptors are differentially involved in cognitive and emotional functions beyond working memory. We found an inverted U-shaped relation between prefrontal D1 receptor availability and Wisconsin Card Sorting Test performance, indicating that too little or too much D1 receptor stimulation impairs working memory or set shifting. In addition, variability of D1 receptor availability in the amygdala and striatum was related to individual differences in emotional responses and decision-making processes, respectively. These observations suggest that the variability of available D1 receptors might be associated with individual differences in brain functions that require phasic dopamine release. An interdisciplinary approach combining molecular imaging of dopamine neurotransmission with cognitive neuroscience and clinical psychiatry will provide new perspectives for understanding the neurobiology of neuropsychiatric disorders such as schizophrenia, addiction and Parkinson's disease, as well as novel therapeutics for cognitive impairments observed in them

Effect of Extremely Low-Frequency(ELF) Magnetic Field on Anticancer Drugs Potency

There are some reports about combined effects of electromagnetic fields with known carcinogens, toxic physical or chemical agents. In previous study, we observed that magnetic fields (60 Hz, 50 mT) enhance cytotoxicity of mitomycin C on E.coli bacterium. However, it has not been clear about the effective condition of magnetic fields (magnetic flux density, frequency, exposure time etc.) on the potency of chemical agents. In this study, we investigated the effective density and the action mechanisms of magnetic fields on the enhancement of drugs potency. The result suggested that the enhancing effect of mitomycin C potency by exposure to magnetic fields depended on the magnetic flux density. The potency of cisplatin, widely used in clinical cancer chemotherapy, was also enhanced by exposure to 60 Hz, 50 mT magnetic fields. The analysis of the potency of supernatant remaining drugs in the culture medium indicated that the intracellular drug potency was increased and extracellular drug potency was decreased by exposure to magnetic fields. The values of drug potency revealed a significant inverse correlation between intracellular and extracellular cells. These results suggested that magnetic fields (60 Hz, 50 mT) change the permeability of cell membrane and influence the drug intake

Finite Element Analysis of Nonlinear Magnetic Devices Combined with Circuit Equations by Tableau Approach

When simulating electric machines, the magnetic field analysis and the circuit calculation are coupled closely. We present a method in which the combination of Maxwell\u27s equations and circuit equations is solved simultaneously. The tableau approach as nodal formulation is applied to the circuit model. This paper describes a new generalized approach for considering the external networks in the harmonic balance finite element method we proposed. The approach is applied to the analysis of a magnetic frequency tripler with circuit elements

Low-Invasive Detection of Magnetic Particles inside Human Body

[研究報告

Oil-in-water emulsion lotion providing controlled release using 2-methacryloyloxyethyl phosphorylcholine n-butyl methacrylate copolymer as emulsifier

AbstractLotion is a useful vehicle for active ingredients used to treat skin disease because it can be applied to the scalp, can cover large areas of skin, and it is easy to spread due to low viscosity. An emulsion lotion (EL) containing 2-methacryloyloxyethyl phosphorylcholine n-butyl methacrylate copolymer (PMB) as an emulsifier that provides controlled-release was developed. Diphenhydramine (DPH) was used as a model drug. Formulation with 5% DPH, 5% soybean oil, and 4% PMB in water was emulsified using a high-pressure homogenizer. Polysorbate 80 (TO) was used instead of PMB for comparison. They were applied in vitro to Yucatan micropig intact or stripped skin at a practical dose (2μL/cm2). For stripped skin, penetration of DPH from 4% PMB EL was slower than that from 1% TO EL; results for intact skin were similar. The same phenomenon was observed with application to rabbit skin in vivo. When 4% PMB EL dried on the skin, it made a thin film matrix incorporating the oil phase, which controlled the release of DPH. The release rate could be controlled by the ratio of oil phase to PMB. The EL with PMB shows promise as a vehicle for long-acting treatment of skin diseases

Micron size GMR magnetic sensor with needle structure

The work presents inimitable shaped needle type probe with spin valve giant magnetoresistance (SV-GMR) elements. Sensitive elements with 75 μm width are connected in the Wheatstone bridge structure. The length of the needle is 20-30 mm and its cross section is square. The magnetic sensor probe has the advantage of micron order spatial resolution. The needle type probe works as a gradient meter which concurrently suppresses the influence of externally applied field and detects magnetic fields emanating from nano or micro order size sources. Sensing elements present high sensitivity 260 μV/μT and are capable of detecting the magnetic fields in order of few nT. SV-GMR elements present flat amplitude and phase characteristics in wide frequency range. The novel characteristicsof the probe allow it to be utilized in detection of the in-phase and out of phase signal components. An additional merit of this design is extremely small liftoff height between sensing element and the source of magnetic field. The SV-GMR elements are isolated only by very thin protection layer (a few μm), that gives opportunity to apply the probe in biological (in vivo) experiments, and in non destructive evaluation of current detection. The needle shape allows the sensing element toapproach the examined materials in a distance of few ten μm. © 2012 American Institute of Physics

Genome structure of the Lactobacillus temperate phage Φg1e: the whole genome sequence and the putative promoter/repressor system

The complete genome sequence of a Lactobacillus temperate phage Φg1e was established. The double-stranded DNA is composed of 42 259 bp, and encodes for sixty-two possible open reading frames (ORF) as well as several potential regulatory sequences. Based on comparative analysis with other related proteins of the Lactobacillus and Lactococcus phages as well as the Escherichia coli phages (such as lambda), functions were putatively assigned to several Φg1e ORFs: cng and cpg (encoding for repressors), hel (helicase), ntp (NTPase), and several ORFs (e.g., minor capsid proteins). An about 1000-bp DNA region of Φg1e containing cpg and cng was inferred to function as a promoter/repressor system for the Φg1e lysogenic and lytic pathway

Monitoring Minute chances of Magnetic Maekers\u27 Susveptability by SV-GMR Needle-Type Probe

The aim of this study is to present the novel methodology for magnetic markers immunoassay measurements by spin valve giant magnetoresistive (SV-GMR) needle probe. Extremely small size and specific construction of this probe type allow detecting the changes of complex susceptibility directly from the sample. The needle-type probe consists of four SV-GMR elements connected in a Wheatstone bridge and it has sensitivity of 11 V/ T. The SV-GMR sensing element has dimensions of 40 m 75 m. This paper presents a setup feasible to perform spectroscopic magnetic markers measurement. It includes data related to signal changes caused by the magnetic markers dilution. It shows the influence of particle size changes (120 nm, 1 m, 3.5 m, 6.5 m) on real and imaginary parts of the complex susceptibility of the specimen. While performing measurements, probe sensing elements were placed inside the sample. Monitoring changes of samples susceptibility allows performing homogenous immunoassay measurements in a liquid phase by SV-GMR probe. Based on the measurement results, analytical model of changes of complex susceptibility is derived and described

Fluctuation of Resonance Frequency of Applicator Having Wireless Power Transmission for Hyperthermia Therapy

One of the hyperthermia therapies is hgh-frequency induction heating type by using nano-mgnetic materials and magnetic implants. A tumor with injected magnetic materials is heated by hysteresis loss and eddy-current loss under high frequency magnetic fields with a few handred kHz. To generate magnetic fields at the deep position of a body, we proposed a double pancake type exciting system with wireless power transmission. Since this system is constituted by two tuned resonant circuits, the characteristic is sensitive to the change of parameters. This paper discusses the fluctuations of resonance frequency depending on the change of a distance between the exciting and induced coils and resonance capacitor. As a result, we recognized the fluctuation range of the resonance frequency for a tuned exciting power source