DNA base pairing has been used for many years to direct the arrangement of inorganic nanocrystals into small groupings and arrays with tailored optical electrical properties. The control DNA-mediated assembly depends crucially on a better understanding three-dimensional structure DNA-nanocrystal-hybridized building blocks. Existing techniques do not allow structural determination these flexible heterogeneous samples. Here we report cryo-electron microscopy negative-staining electron...

Cerenkov luminescence imaging (CLI) is a cost-effective molecular tool for biomedical applications of radiotracers. The introduction tomography (CLT) relative to planar CLI can be compared the development X-ray CT based on radiography. With CLT, quantitative and localized analysis radiopharmaceutical distribution becomes feasible. In this contribution, feasibility study in vivo heterogeneous medium presented. Coupled with multimodal system, CLT reconstruction method allows precise anatomical...

Bioluminescence tomography (BLT) poses a typical ill-posed inverse problem with large number of unknowns and relatively limited boundary measurements. It is indispensable to incorporate priori information into the formulation in order obtain viable solutions. In paper, Bayesian approach has been firstly suggested multiple types for BLT reconstruction. Meanwhile, generalized adaptive Gaussian Markov random field (GAGMRF) prior model unknown source density estimation developed further reduce...

Cholesteryl ester transfer protein (CETP) mediates cholesteryl (CE) from the atheroprotective high density lipoprotein (HDL) cholesterol to atherogenic low cholesterol. In past decade, this property has driven development of CETP inhibitors, which have been evaluated in large scale clinical trials for treating cardiovascular diseases. Despite pharmacological interest, little is known about fundamental mechanism CE transfer. Recent electron microscopy (EM) experiments suggested a tunnel...

Abstract Cholesteryl ester transfer protein (CETP) mediates the net of cholesteryl esters (CEs) from atheroprotective high‐density lipoproteins (HDLs) to atherogenic low‐density (LDLs) or very‐low‐density (VLDLs). Inhibition CETP raises HDL cholesterol (good cholesterol) levels and reduces LDL (bad levels, making it a promising drug target for prevention treatment coronary heart disease. Although crystal structure has been determined, molecular mechanism mediating CEs is still unknown, even...

Apolipoprotein A-I (apo A-I), the major protein component of high-density lipoprotein, has been proven inversely correlated to cardiovascular risk in past decades. The lipid-free state apo is initial stage which binds lipids forming lipoprotein. Molecular models have reported by methods like X-ray crystallography and chemical cross-linking/mass spectrometry (CCL/MS). Through structural analysis we found that those current had limited consistency with other experimental results, such as from...

Corona discharge, an inevitable phenomenon, may lead to insulation degradation, threatening the safe and reliable operation of gas-insulated power equipment. The pulse stage is a complex but usual discharge process in corona discharge. In this paper, we investigate characteristics negative needle-to-plane electrode configuration SF6/N2 gas mixtures under DC voltages. With increase mean current, transition phenomenon from Townsend through breakdown observed. variation amplitude time at...

Corona discharge will affect the performance of insulating gas, threatening safe and reliable operation gas-insulated power equipment. In this paper, we investigate negative corona characteristics in SF6/N2 gas mixtures with trace SF6 [φ(SF6) ≤ 1%] under DC voltages. With decreasing content, two types discharge–stage transition process as a function mean current are observed. One is from Townsend stage, through pulse to breakdown stage; other one presents normal-glow stage between stage. The...

Negative corona discharge can deflect in transverse airflow pin-to-plane electrodes at atmospheric pressure. In this paper, we investigate the mechanism of Trichel pulse deflection and give a further understanding dynamic process through experiments simulations. experiments, quantitatively record angle by processing images, they show that larger speed will lead to angle. simulations, is calculated 2D fluid model. Besides, periodic fluctuation with pulses revealed, phenomenon be explained...

The pulsed mode of negative DC corona discharge in nitrogen at atmosphere pressure is investigated needle–plate electrodes and compared with Trichel pulses air. Current/voltage waveforms time-resolved pictures are recorded experimentally. It found that the only appears presence a large ballast resistor. slope time-averaged voltage–current curve negative, contrast to pulses. A transition from positive tracked by increasing oxygen fraction. development pulse can be divided into three stages:...

Dielectric response is closely related to the aging status of XLPE cables, and isothermal relaxation current (IRC) has been applied find out change trend cable insulation as a non-destructive method. In this paper, 4 groups samples (16 cables in total) are artificially acceleratedly aged with different time interval at 120, 140 160°C, respectively, their IRC curves measured by micro-current device. The results show that increasing time, decrease slower absolute values steady become larger....

Cross-linked polyethylene (XLPE) insulation cable is the main type of in use now. Its aging with increasing service years. Two methods are used to diagnose condition insulation-polarization/depolarization current (PDC) and frequency domain spectroscopy (FDS). The PDC a time method, while FDS domain. In this paper, we put forward method get dissipation factor curve under low by carrying out experiment. This based on three R-C series branches extended Debye model. model each branch stands for...

Positive streamers can be affected significantly by preceding discharges such as earlier or a corona discharge. In this paper, we primarily discuss the effect of discharge on subsequent positive with different intervals between them (0/500/990 ms) in air and pure nitrogen at 80 mbar repetition frequency 1 Hz. We found that air, when interval time is 500 990 ms, leads to shorter weaker even prevents streamer inception altogether. This likely due negative ions which have converted species are...

Cross-linked polyethylene (XLPE) insulation cable is widely used in distribution power system, so it important to reasonably estimate status. Cable mainly affected by high temperature and water tree. Therefore, this paper, we use PDC method evaluate insulation, which non-destructive due its low voltage. In order find out the relationship between curve aging status, put 5 single-core samples oven set as 140C. Then, divide these into different time (new, 10 days, 20 30 40 days) measure curve....

Releasing plasma cloud is an efficient way to manage ionosphere properties. In this paper, we establish a three-dimensional fluid model simulate the spatiotemporal evolution of released Cs plasma. Four types particles are taken into account: neutral Cs, ambient O, Cs+ and electron, among which electron move according classical ambipolar diffusion. Meanwhile, photoionization induced by solar radiation recombination Cs+/electron included in as two chemical reactions. Based on model,...

Powerful lasers hold promise for guiding streamer discharges in air, with applications ranging from plasma etching to lightning control. This paper numerically investigates the guidance of positive streamers by laser-produced pre-ionization (a uniform ionization trail consisting free electron-ion pairs) air a 3D PIC/MCC model. Initially, grows toward laser beam due electrostatic attraction caused charge separation within channel. As electrons drift near streamer, they trigger electron...

The electrical and optical characteristics of DBD are different from those bare electrodes, while the Paschen curve reflects relationship between breakdown voltage gas pressure gap distance. specific in need to be differentiated. closely related discharge mode. mode can divided into filamentous uniform discharge. plasma contains a large number excited particles, which radiate at low energy level. After being recorded by ICCD camera, emission spectrum obtained. By analyzing intensity location...

Among many optical molecular imaging modalities, bioluminescence (BLI) has more and wide application in tumor detection evaluation of pharmacodynamics, toxicity, pharmacokinetics because its noninvasive cellular level ability, high sensitivity low cost comparison with other technologies. However, BLI can not present the accurate location intensity inner sources such as bone, liver or lung etc. Bioluminescent tomography (BLT) shows advantage determining source distribution inside a small...

Pulsed mode as a common phenomenon appears in many kinds of DC corona discharge, whose characteristics can be affected by some specific factors. In this paper, an important research field pulsed mode, pulsed–pulseless transition, is investigated needle–plate electrodes nitrogen at atmospheric pressure, and we discuss the effect external circuit, gas temperature, associative ionization on transition experiment simulation. The circuit coupling with plasma make pulseless achieved when there...

In this work, the influence of varying mixing ratios O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> on positive streamer initiation in supercritical (SC) CO at different applied voltages was investigated using a 3-D particle model. Zener's model included to calculate field ionization rate during formation and propagation. The evolution classified into three main stages namely inception cloud, primary channels, successive branching....