Low conductance injection tubes for storage cell targets

The effect of adding internal fins to the injection tube of a storage cell target filled with a polarized atomic beam source has been studied. The tube conductance and the atomic beam intensity at the exit of the injection tube have been measured, observing an unexpectedly large beam loss. Simulations of the atomic beam reproduce the observed attenuation only when the non-zero azimuthal component of the atom's velocity is taken into account.

Miniaturized tris(2,2 '-bipyridyl)ruthenium(II) electrochemiluminescence detection cell for capillary electrophoresis and flow injection analysis

The design and performance of a miniaturized chip-type tris(2,2'-bipyridyl)ruthenium(II) [Ru(bpy)(3)(2+)] electrochemiluminescence (ECL) detection cell suitable for both capillary electrophoresis (CE) and flow injection (FI) analysis are described. The cell was fabricated from two pieces of glass (20 x 15 x 1.7 mm), and the 0.5-mm-diameter platinum disk was used as working electrode held at +1.15 V (vs silver wire quasi-reference), the stainless steel guide tubing as counter electrode, and the silver wire as quasi-reference electrode. The performance traits of the cell in both CE and FI modes were evaluated using tripropylamine, proline, and oxalate and compared favorably to those reported for CE and FI detection cells. The advantages of versatility, sensitivity, and accuracy make the device attractive for the routine analysis of amine-containing species or oxalate by CE and FI with Ru(bPY)(3)(2divided by) ECL detection.

DIRECT-INJECTION OF URINE AND DETERMINATION OF ACETAMINOPHEN BY MICELLAR LIQUID-CHROMATOGRAPHY WITH A WALL-JET CELL CARBON-FIBER MICROELECTRODE

A wall-jet cell/carbon fibre microelectrode detector was designed and used for the micellar liquid chromatographic assay of acetaminophen. The separations were carried out in an analytical column packed with C-18 stationary phase and the mobile phase was

Electron self-injection and acceleration driven by a tightly focused intense laser beam in an underdense plasma

A scheme for electron self-injection in the laser wakefield acceleration is proposed. In this scheme, the transverse wave breaking of the wakefield and the tightly focused geometry of the laser beam play important roles. A large number of the background electrons are self-injected into the acceleration phase of the wakefield during the defocusing of the tightly focused laser beam as it propagates through an underdense plasma. Particle-in-cell simulations performed using a 2D3V code have shown generation of a collimated electron bunch with a total number of 1.4 x 109 and energies up to 8 MeV. (C) 2005 American Institute of Physics.

Electron injection by a nanowire in the bubble regime

The triggering of wave-breaking in a three-dimensional laser plasma wake (bubble) is investigated. The Coulomb potential from a nanowire is used to disturb the wake field to initialize the wave-breaking. The electron acceleration becomes more stable and the laser power needed for self-trapping is lowered. Three-dimensional particle-in-cell simulations were performed. Electrons with a charge of about 100 pC can be accelerated stably to energy about 170 MeV with a laser energy of 460 mJ. The first step towards tailoring the electron beam properties such as the energy, energy spread, and charge is discussed. (C) 2007 American Institute of Physics.

Intraperitoneal injection of extracted microcystins results in hypovolemia and hypotension in crucian carp (Carassius auratus)

Circulatory responses of crucian carp injected intraperitoneally with extracted micro-cystins (MCs) were studied at sublethal and lethal doses (150 and 600 mu g MC kg(-1) body mass, respectively). Mean arterial blood pressure (MAP), heart rate, hematocrit (Hct), red blood cell (RBC) counts, and circulating blood volume (BV) were assayed at 0, 1, 3, 12, 24, and 48 h post-toxin administration. MAP decreased significantly in a dose-dependent manner over time. Within the 48-h test period, the lethal dose as well as the sublethal dose resulted in a steady decline of MAP without recovery. Heart rate significantly increased within 24 h post-injection as blood pressure significantly dropped, then showed a terminal decline to the control level. The dose-dependent decreases in BV and Hct were directly related to the drop in MAP. Intraperitoneal injection of a lethal dose of MCs led to hepatic and gill hemorrhage. Consequently, crucian carp given MCs suffered from hypovolemic hypotensive shock. (C) 2009 Elsevier Ltd. All rights reserved.

Hematological and plasma biochemical responses of crucian carp (Carassius auratus) to intraperitoneal injection of extracted microcystins with the possible mechanisms of anemia

Alterations in hematological indices such as decreases in blood cell counts (RBC), hematocrit (Ht) and hemoglobin (Hb) concentrations are key symptoms of anemia. However, few experiments were conducted to examine changes in hematological indices of fish exposed to microcystins that are believed to be fatal to circulatory systems of vertebrates. An acute toxicological experiment was designed to study hematological changes of crucian carp injected intraperitoneally (i.p.) with extracted microcystins at two doses, 50 and 200 mu g MC-LReqkg(-1) body weight. After being i.p. injected with microcystins, the fish exhibited behavioral abnormity. There were significant decreases in RBC in the high-dose group, and in Ht and Hb concentrations in both dose groups, while erythrocte sedimentation rate (ESR) significantly increased, indicating the appearance of normocytic anemia. There were no prominent changes in the three red cell indices, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH,), and mean corpuscular hemoglobin concentration (MCHC). Increases in blood urea nitrogen (BUN) and creatinine (CR) in both dose groups suggest the occurrence of kidney impairment. Alteration in blood indices was reversible at the low dose group. Conclusively, anemia induced by kidney impairment was a key factor to cause abnormity of swimming behaviors and high mortality of crucian carp. (c) 2007 Elsevier Ltd. All rights reserved.

A Particle-in-cell scheme of the RFQ in the SSC-Linac

A 52 MHz Radio Frequency Quadrupole (RFQ) linear accelerator (linac) is designed to serve as an initial structure for the SSC-Linac system (injector into Separated Sector Cyclotron). The designed injection and output energy are 3.5 keV/u and 143 keV/u, respectively. The beam dynamics in this RFQ have been studied using a three-dimensional Particle-In-Cell (PIC) code BEAMPATH. Simulation results show that this R,FQ structure is characterized by stable values of beam transmission efficiency (at least 95%) for both zero-current mode and the space charge dominated regime. The beam accelerated in the RFQ has good quality in both transverse and longitudinal directions, and could easily be accepted by Drift Tube Linac (DTL). The effect of the vane error and that of the space charge on the beam parameters have been studied as well to define the engineering tolerance for RFQ vane machining and alignment.

Injection by hydrostatic pressure in conjunction with electrokinetic force on a microfluidic chip

A simple method was developed for injecting a sample on a cross-form microfluidic chip by means of hydrostatic pressure combined with electrokinetic forces. The hydrostatic pressure was generated simply by adjusting the liquid level in different reservoirs without any additional driven equipment such as a pump. Two dispensing strategies using a floating injection and a gated injection, coupled with hydrostatic pressure loading, were tested. The fluorescence observation verified the feasibility of hydrostatic pressure loading in the separation of a mixture of fluorescein sodium salt and fluorescein isothiocyanate. This method was proved to be effective in leading cells to a separation channel for single cell analysis.

Flow injection electrochemical enzyme immunoassay based on the use of an immunoelectrode strip integrate immunosorbent layer and a screen-printed carbon electrode

A flow injection amperometric immunoassay system based on the use of screen-printed carbon electrode for the detection of mouse IgG was developed. An immunoelectrode strip, on which an immunosorbent layer and screen-printed carbon electrode were integrated, and a proposed flow cell have been fabricated. The characterization of the flow immunoassay system and parameters affecting the performance of the immunoassay system were studied and optimized. Amperometric detection at 0.0 V (versus Ag/AgCl) resulted in a linear detection range of 30-700 ng ml(-1), with a detection limit of 3 ng ml(-1). The signal variation among electrode strips prepared from variant batch did not exceed 8.5% (n = 7) by measuring 0.5 mug ml(-1) antigen standard solution.

HIGHLY SENSITIVE AND SELECTIVE DETERMINATION OF RIBOFLAVIN BY FLOW-INJECTION ANALYSIS USING PARALLEL DUAL-CYLINDER MICROELECTRODES

A novel wall-jet cell with parallel dual cylinder (PDC) microelectrodes was constructed and used for flow injection analysis (FLA). The detector takes the advantages of ''redox recycling'' between bipotentiostated microcylinder electrodes (- 0.4 V/SCE an

AMPEROMETRIC DETECTION AT A CARBON-FIBER ARRAY RING GLASSY-CARBON DISK ELECTRODE IN A WALL-JET CELL

A wall-jet cell incorporating a carbon fibre array ring/glassy-carbon disk electrode has been constructed, and characterized by the cyclic voltammetry and flow-injection techniques. The ring (composed of several microdisks) and glassy-carbon disk electrode, can be used separately for different purposes, e.g., detection in solution without a supporting electrolyte, collection/shielding detection with dual-electrode and voltammetric/amperometric detection with series dual-electrode. The electrode shows better collection and shielding effects than usual ring-disk electrode in quiescent solution and the series dual-electrode in a thin-layer flow-through cell. The detection limit at the ring electrode is comparable with that at a conventional-size electrode, and has been used in the mobile phase without a supporting electrolyte, proving to be a promising detector for normal-phase liquid chromatography.