The integrated diagnostic suite of the C-2W experimental field-reversed configuration device and its applications

In the current experimental device of TAE Technologies, C-2W (also called "Norman"), record breaking advanced beam-driven field-reversed configuration (FRC) plasmas are produced and sustained in steady state utilizing variable energy neutral beams (15-40 keV, total power up to 20 MW), advanced divertors, bias electrodes, and an active plasma control system. This fully operational experiment is coupled with a fully operational suite of advanced diagnostic systems. The suite consists of 60+ individual systems spanning 20 categories, including magnetic sensors, Thomson scattering, interferometry/polarimetry, spectroscopy, fast imaging, bolometry, reflectometry, charged and neutral particle analysis, fusion product detection, and electric probes. Recently, measurements of main ion temperatures via a diagnostic neutral beam, axial profiles of energy flux from an array of bolometers, and divertor and edge plasma parameters via an extensive set of electric probes, interferometers, and spectrometers have all been made available. All the diagnostics work together to provide a complete picture of the FRC, fast-ion inventory, and edge plasma details enabling tomographic reconstruction of plasma parameter profiles and real-time plasma control.

Thomson scattering systems on C-2W field-reversed configuration plasma experiment

TAE Technologies' newly constructed C-2W experiment aims to improve the ion and electron temperatures in a sustained field-reversed configuration plasma. A suite of Thomson scattering systems has been designed and constructed for electron temperature and density profile measurements. The systems are designed for electron densities of 1 × 10¹² cm^-3 to 2 × 10¹⁴ cm^-3 and temperature ranges from 10 eV to 2 keV. The central system will provide profile measurements of T_e and n_e at 16 radial locations from r = -9 cm to r = 64 cm with a temporal resolution of 20 kHz for 4 pulses or 1 kHz for 30 pulses. The jet system will provide profile measurements of T_e and n_e at 5 radial locations in the open field region from r = -5 cm to r = 15 cm with a temporal resolution of 100 Hz. The central system and its components have been characterized, calibrated, installed, and commissioned. A maximum-likelihood algorithm has been applied for data processing and analysis.

Characterization and calibration of the Thomson scattering diagnostic suite for the C-2W field-reversed configuration experiment

The new C-2W Thomson scattering (TS) diagnostic consists of two individual subsystems for monitoring electron temperature (T_e) and density (n_e): one system in the central region is currently operational, and the second system is being commissioned to monitor the open field line region. Validating the performance of the TS's custom designed system components and unique calibration of the detection system and diagnostic as a whole is crucial to obtaining high precision T_e and n_e profiles of C-2W's plasma. The major components include a diode-pumped Nd:YAG laser which produces 35 pulses at up to 20 kHz, uniquely designed collection lenses with a fast numerical aperture, and uniquely designed polychromators with filters sets to optimize a T_e ranging from 10 eV to 2 keV. This paper describes the design principles and techniques used to characterize the main components of the TS diagnostic on C-2W, as well as the results of Rayleigh scattering calibrations performed for the whole system response.

A Method to Encapsulate Small Organic Molecules in Calcium Phosphate Nanoparticles Based on the Supramolecular Chemistry of Cyclodextrin

Calcium phosphate nanoparticles (CPNPs) encapsulating small organic molecules, such as imaging agents and drugs, are considered to be ideal devices for cancer diagnosis or therapy. However, it is generally difficult to encapsulate small organic molecules in CPNPs because of the lack of solubility in water or binding affinity to calcium phosphate. To solve these issues, we utilized the carboxymethyl β-cyclodextrin (CM-β-CD) to increase the solubility and binding affinity to small organic molecules for the encapsulation into CPNPs in this work. The results indicated that the model molecules, hydrophilic rhodamine B (RB) and hydrophobic docetaxel (Dtxl), are successfully encapsulated into CPNPs with the assistance of CM-β-CD. We also demonstrated the CPNPs could be remarkably internalized into A549 cells, resulting in the efficient inhibition of tumor cells' growth.

Encapsulation of cisplatin in a pegylated calcium phosphate nanoparticle (CPNP) for enhanced cytotoxicity to cancerous cells

HYPOTHESIS

Exchange of the chloride ion (Cl^-) ligands of cisplatin with carboxylates is widely used in fabricating cisplatin loaded nanoparticles for improved cancer therapy. However, the dynamic exchange may cause premature cisplatin release and even disintegration of the nanoparticles in Cl^--containing medium such as in plasma. Molecules bearing carboxylates are capable of mediating the mineralization process of calcium phosphate; therefore, it is possible to overcome the disadvantage by sequestering cisplatin in a calcium phosphate nanoparticle (CPNP).

EXPERIMENTS

With the hypothesis, precipitation reaction of calcium nitrate and disodium hydrogen phosphate was performed in a solution of poly(ethylene glycol)-poly(acrylic acid) block copolymers with their carboxylates partly conjugated with cisplatin. Then, structure, physicochemical properties, and bioactivity of the product were carefully investigated with multiple characterization methods.

FINDINGS

It was revealed a pegylated, cisplatin encapsulated CPNP was prepared; and with appropriate mole ratio of cisplatin to carboxylates, the nanoparticle encapsulated cisplatin efficiently (>90%), was stable and almost entirely prevented the cisplatin release in Cl^--containing medium at pH 7.4 but released them in an acidic condition, and showed moderately and greatly enhanced cytotoxicities to the lung cancer cell line A549 and its cisplatin resistance form A549R respectively in comparison with the free cisplatin.

The upgrade of the Thomson scattering system for measurement on the C-2/C-2U devices

The C-2/C-2U Thomson scattering system has been substantially upgraded during the latter phase of C-2/C-2U program. A Rayleigh channel has been added to each of the three polychromators of the C-2/C-2U Thomson scattering system. Onsite spectral calibration has been applied to avoid the issue of different channel responses at different spots on the photomultiplier tube surface. With the added Rayleigh channel, the absolute intensity response of the system is calibrated with Rayleigh scattering in argon gas from 0.1 to 4 Torr, where the Rayleigh scattering signal is comparable to the Thomson scattering signal at electron densities from 1 × 10¹³ to 4 × 10¹⁴ cm^-3. A new signal processing algorithm, using a maximum likelihood method and including detailed analysis of different noise contributions within the system, has been developed to obtain electron temperature and density profiles. The system setup, spectral and intensity calibration procedure and its outcome, data analysis, and the results of electron temperature/density profile measurements will be presented.

Genetic characterization of Toxoplasma gondii from domestic animals in central China

Toxoplasma gondii is an obligate intracellular parasite that has a remarkable ability to infect almost all warm-blooded animals, including humans. This study was aimed to determine the genetic characteristics of T. gondii isolates from domestic animals in Henan Province, central China. A total of 363 DNA samples, including 208 from hilar lymph nodes of pigs, 36 from blood samples of cats, 12 from tissues of aborted bovine fetuses and 107 from blood samples of dams with history of abortion in Henan Province, were examined for the presence of T. gondii by nested PCR based on B1 gene. The positive DNA samples were further genotyped by PCR-RFLP at 11 markers, including SAG1, (3'+ 5') SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico. DNA samples from 9 pigs, 5 cats, and 4 dairy cows were T. gondii B1 gene positive. Nine samples were successfully genotyped at all genetic loci, of which 5 samples from pigs, and 2 from cats were identified as ToxoDB genotype #9, and 2 samples from cows belonged to ToxoDB genotype #225. To our knowledge, the present study is the second report of genetic typing of T. gondii isolates from cattle in China, and the first report of T. gondii ToxoDB#225 from cattle.

Alteration of vascular reactivity in heart failure: role of phosphodiesterases 3 and 4

BACKGROUND AND PURPOSE

This study examined the role of the main vascular cAMP-hydrolysing phosphodiesterases (cAMP-PDE) in the regulation of basal vascular tone and relaxation of rat aorta mediated by β-adrenoceptors, following heart failure (HF).

EXPERIMENTAL APPROACH

Twenty-two weeks after proximal aortic stenosis, to induce HF, or SHAM surgery in rats, we evaluated the expression, activity and function of cAMP-PDE in the descending thoracic aorta.

KEY RESULTS

HF rat aortas exhibited signs of endothelial dysfunction, with alterations of the NO pathway, and alteration of PDE3 and PDE4 subtype expression, without changing total aortic cAMP-hydrolytic activity and PDE1, PDE3 and PDE4 activities. Vascular reactivity experiments using PDE inhibitors showed that PDE3 and PDE4 controlled the level of PGF2α -stimulated contraction in SHAM aorta. PDE3 function was partially inhibited by endothelial NO, whereas PDE4 function required a functional endothelium and was under the negative control of PDE3. In HF, PDE3 function was preserved, but its regulation by endothelial NO was altered. PDE4 function was abolished and restored by PDE3 inhibition. In PGF2α -precontracted arteries, β-adrenoceptor stimulation-induced relaxation in SHAM aorta, which was abolished in the absence of functional endothelium, as well as in HF aortas, but restored after PDE3 inhibition in all unresponsive arteries.

CONCLUSIONS AND IMPLICATIONS

Our study underlines the key role of the endothelium in controlling the contribution of smooth muscle PDE to contractile function. In HF, endothelial dysfunction had a major effect on PDE3 function and PDE3 inhibition restored a functional relaxation to β-adrenoceptor stimulation.

Simultaneous HPLC determination of four active compounds in fengshiding capsules, a chinese medicine

A high performance liquid chromatography method was established for simultaneously determining four bioactive components, salicin, liquiritin, paeonolum, and imperatorin in Fengshiding capsule, a widely used traditional Chinese medicine for treating rheumatic disease. The chromatographic separation was performed on a Shimadzu Shim-pack Stable Bond C18 column using gradient elution with methanol and water. The analytical method was validated through precision, repeatability and stability, and the relative standard deviation values were less than 3%, respectively. The recoveries of the four investigated compounds ranged from 95.80 to 101.21% with relative standard deviation values less than 3.2%. Then this proposed method was successfully applied to determine six batches of Fengshiding commercial products of capsule dosage form from two pharmaceutical factories. This study might provide a basis for quality control for this traditional Chinese medicine preparation.

Experimental demonstration of improved neoclassical transport with quasihelical symmetry

Differences in the electron particle and thermal transport are reported between plasmas produced in a quasihelically symmetric (QHS) magnetic field and a configuration with the symmetry broken. The thermal diffusivity is reduced in the QHS configuration, resulting in higher electron temperatures than in the nonsymmetric configuration for a fixed power input. The density profile in QHS plasmas is centrally peaked, and in the nonsymmetric configuration the core density profile is hollow. The hollow profile is due to neoclassical thermodiffusion, which is reduced in the QHS configuration.