Inhibitory effects of flavonoids on human immunodeficiency virus type-I integrase

One hundred and eighty-three flavonoids were screened for their inhibitory effects on HIV-l integrase (IN) using a multiplate integration assay (MIA). Of the tested flavonoids, 6-hydroxyluteolin, scutellarein, pedalitin, scutellarin, baicalein dimer, hypolaetin, 7-O-benzyl-6-hydroxyluteolin and baicalein showed appreciable inhibition with IC_ values of 0.4, 0.6, 1.3, 1.7, 2.0, 2.1, 3.0 and 3.6 μM, respectively. The potent inhibition was observed with flavonoids having at least one pair of vicinal hydroxyl groups and the activity was highly dependent on the number of vicinal hydroxyl groups. On the other hand, the inhibitory activity tended to be decreased by replacing a hydroxyl group with one of methoxyl, acetoxyl, isopropoxyl, isopentenyl, benzyloxyl, glucuronyl and glycosyl groups. No flavanones, flavanonols and chalcones examined in this experiment showed any significant inhibitory activity. マルチプレートインテグレーション法を用いて183種のフラボノイド類のHIV-1インテグラーゼ阻害効果を検討した。これらのうち6-hydroxyluteolin, scutellarein, pedalitin, scutellarin, baicalein二量体,hypolaetin,7-O-benzyl-6-hydroxyluteolinおよびbaicaleinは強い阻害を示し,それらの50%阻害濃度はそれぞれ0.4, 0.6, 1.3, 1.7, 2.0 ,2.1 ,3.0および3.6μMであった。フラボノイド類による阻害には少なくとも一対の隣接したヒドロキシル基が必要であった。また,隣接したヒドロキシル基の数が増加するに従い,HIV-1インテダラーゼ阻害活性も上昇した。他方,ヒドロキシル基がmethoxyl基, acetoxyl基, isopropoxyl基, isopentenyl基, benzyloxyl基, glucuronyl基 及びglycosyl基に置換されると阻害活性は減少あるいは消失した。試験したフラバノン,フラバノール,カルコン類には顕著な阻害活性は認められなかった

Optics Design for Microwave Imaging Reflectometry in LHD

An optics system for microwave imaging reflectometry (MIR) in the Large Helical Device (LHD) was newly developed to optimize the performance of the two-dimensional microwave receiver array. Reflected microwaves from the plasma and the first local oscillator (LO) wave are transmitted to the receiver array via the optics from the front. Finite-difference time-domain (FDTD) calculation was used to design the ellipsoidal or hyperboloidal shapes of the quasi-optical mirrors. It is confirmed that the LO beam in the constructed system covers the receiver antenna aperture area as intended. The S/N ratios of the signals are improved with this optimized optics system from those in the previous system

Study of Electron Orbits for Formation of Toroidal Closed Flux Surface by ECH

Electron orbits under the external vertical field (BV) and the self poloidal field of the toroidal plasma current in a toroidal geometry are investigated by using analytic model fields in order to search for the conditions of occurence of appropriate confinement asymmetry of fast electrons along the field lines. This asymmetry efficiently and quickly generates a toroidal current, which may close the field lines in ECH-started plasmas. It is analytically shown that the characteristics of confinement asymmetry depend on the product of the major radius and the strength of the external vertical field. The results suggest that in large devices BV should be lowered and also some artificial means to speed up the pitch angle scattering for the fast electrons at a higher energy range are beneficial to generate the toroidal current in order to close the filed lines

Spontaneous Formation of Spherical Tokamak by ECH on LATE

Spontaneous formation of spherical tokamak is observed during a microwave discharge at the electron cyclotron resonance (ECR) under a steady vertical magnetic field. In the course of slow plasma current increase, a fast rise of current (usually within several ms) occurs and the magnetic field topology changes drastically from open field type to closed one. After this current jump, a steady plasma current is maintained. The plasma current in the steady stage is proportional to the strength of the vertical field which balances the outward hoop force of the plasma current and maintains the MHD equilibrium. When a 5GHz, 130kW, 60ms microwave power is injected at 85G vertical field, plasma current of 6.8kA is obtained

Development of a Multi-Channel Horn Mixer Array for Microwave Imaging Plasma Diagnostics

Microwave to millimeter-wave diagnostics techniques, such as interferometry, reflectometry, scattering, and radiometry, have been powerful tools for diagnosing magnetically confined plasmas. The resultant measurements have clarified several physics issues, including instability, wave phenomena, and fluctuation-induced transport. Electron cyclotron emission imaging has been an important tool in the investigation of temperature fluctuations, while reflectometry has been employed to measure plasma density profiles and their fluctuations. We have developed a horn-antenna mixer array (HMA), a 50 - 110 GHz 1D antenna array, which can be easily stacked as a 2D array. This article describes an upgrade to the horn mixer array that combines well-characterized mixers, waveguide-to-microstrip line transitions, intermediate frequency amplifiers, and internal local oscillator modules using a monolithic microwave integrated circuit technology to improve system performance. We also report on the use of a multi-channel HMA system