Differential interferometry for measurement of density fluctuations and fluctuation-induced transport (invited)

Differential interferometry employs two parallel laser beams with a small spatial offset (less than beam width) and frequency difference (1-2 MHz) using common optics and a single mixer for a heterodyne detection. The differential approach allows measurement of the electron density gradient, its fluctuations, as well as the equilibrium density distribution. This novel interferometry technique is immune to fringe skip errors and is particularly useful in harsh plasma environments. Accurate calibration of the beam spatial offset, accomplished by use of a rotating dielectric wedge, is required to enable broad application of this approach. Differential interferometry has been successfully used on the Madison Symmetric Torus reversed-field pinch plasma to directly measure fluctuation-induced transport along with equilibrium density profile evolution during pellet injection. In addition, by combining differential and conventional interferometry, both linear and nonlinear terms of the electron density fluctuation energy equation can be determined, thereby allowing quantitative investigation of the origin of the density fluctuations. The concept, calibration, and application of differential interferometry are presented.

Upgrade of far-infrared laser-based Faraday rotation measurement on MST

Recently, the far-infrared (FIR) laser (λ(0)=432 μm) Faraday rotation measurement system on MST has been upgraded. The dc flowing-gas discharge CO(2) pump laser is replaced by a rf-excited, sealed CO(2) laser at 9.27 μm (GEM select 100, Coherent Inc., Santa Clara, CA), which is subdivided equally into three parts to simultaneously pump three FIR cavities. The total infrared pump power is approximately 80 W on the 9R(20) line required to pump the formic acid molecule. Each FIR cavity produces ∼12 mW, sufficient for 11 simultaneous chord interferometry-polarimetry operations. Three key issues [(1) conservation of circularly polarized wave, (2) colinearity of two probe waves, and (3) stability of intermediate frequencies between lasers] affecting the Faraday rotation measurement have been resolved experimentally.

Hepatic electrical stimulation reduces blood glucose in diabetic rats

BACKGROUND

The aim of this study was to investigate the feasibility and mechanisms of controlling blood glucose using hepatic electrical stimulation (HES).

METHODS

The study was performed in regular Sprague-Dawley (SD) rats, streptozotocin-induced type 1 diabetic rats and Zucker diabetic fatty (ZDF) rats chronically implanted with one pair of stimulation electrodes on two lobes of the liver tissues.

KEY RESULTS

(i) Hepatic electrical stimulation was effective in reducing blood glucose by 27%-31% at time points 60, 75 and 90 min after oral glucose in normal rats; (ii) HES reduced blood glucose in both fasting and fed states in both type 1 and type 2 diabetic rats; (iii) Chronic HES decreased the blood glucose level, and, delayed gastric empty and increased plasma glucagon-like peptide-1 (GLP-1) level; and (iv) No adverse events were noted in any rats during HES. Histopathological analyses and liver function tests revealed no electrode dislodgement, tissue damages or liver enzyme changes with HES.

CONCLUSIONS & INFERENCES

Hepatic electrical stimulation is capable of reducing both fasting and fed blood glucose in normal, and type 1 and type 2 diabetic rats and the effect may be partially mediated via an increase in GLP-1 release.

Highly Efficient Near-IR Photoluminescence of Er Immobilized in Mesoporous SBA-15

SiO(2) mesoporous molecular sieve SBA-15 with the incorporation of erbium ions is studied as a novel type of nanoscopic composite photoluminescent material in this paper. To enhance the photoluminescence efficiency, two schemes have been used for the incorporation of Er(3+) where (1) Er(3+) is ligated with bis-(perfluoromethylsulfonyl)-aminate (PMS) forming Er(PMS)(x)-SBA-15 and (2) Yb(3+) is codoped with Er(3+) forming Yb-Er-SBA-15. As high as 11.17 × 10(-21)cm(2) of fluorescent cross section at 1534 nm and 88 nm of "effective bandwidth" have been gained. It is a 29.3% boost in fluorescent cross section compared to what has been obtained in conventional silica. The upconversion coefficient in Yb-Er-SBA-15 is relatively small compared to that in other ordinary glass hosts. The increased fluorescent cross section and lowered upconversion coefficient could benefit for the high-gain optical amplifier. Finally, the Judd-Ofelt theory has also been used for the analyses of the optical spectra of Er(PMS)(x)-SBA-15.

Pregnancies and piglets from large white sow recipients after two transfer methods of cloned and transgenic embryos of different pig breeds

The aim of this study was to report from a larger study with pregnancy and delivery results after transfer of cloned transgenic/non-transgenic Large White or minipig embryos to Large White sow recipients. The effect of both total numbers of transferred embryos as well as site of their deposition (uni- vs. bi-lateral) was studied. Four to five days after natural heat, 85 Large White (LW) sows received Day 5 or 6 handmade cloned embryos. Large White embryos were non-transgenic and were transferred to 36 recipients, while 49 recipients each received Minipig embryos, either non-transgenic or with 1 of 4 types of transgenes. Furthermore, the number of embryos transferred was in two categories, as 46 recipients received 40-60 embryos while 39 received 60-120 embryos. Finally, in 59 of the recipients embryos were transferred to one of the uterine horns (unicornual) while 26 other recipients had embryos transferred to both uterine horns (bicornual). The overall pregnancy rate was 55% with an abortion rate of 26% resulting in 41% deliveries with no difference between LW and Minipig embryos and no difference between transgenic and non-transgenic Minipig embryos. Transfer of 60-120 embryos resulted in more pregnancies and deliveries (62%) than <60 embryos (24%). The mean litter size was 5.1 ± 0.5 and after transfer of 60-120 embryos significantly higher (6.0 ± 0.5) than after transfer of <60 embryos (3.5 ± 0.8). Also, the bicornual transfer resulted in significantly higher delivery rate (74% vs. 44%) and mean litter size (6.1 ± 0.7 vs. 4.2 ± 0.6) than the unicornual. The mean rate of piglets/transferred embryos was 7.3 ± 0.6% while the mean rate of piglets/reconstructed embryos was 179/18,000 = 1% with no difference between breeds or number of embryos transferred. The overall perinatal mortality rate was 49%, and it was significantly lower in LW piglets (20/59 = 34%) than in Minipiglets (67/120 = 56%) (vs. 10-15% in normal piglets at the farm) and the total rate of piglets with one or more malformation was 22%, and lower in LW (12%) than in Minipiglets (28%). This study demonstrate that although the perinatal mortality was rather high, an acceptable birth rate can be achieved after transfer to LW recipients of cloned LW embryos as well as cloned, transgenic/non-transgenic Minipig embryos. Furthermore, the pregnancy rate and litter size were correlated to the number of embryos transferred and to bicornual transfer.

T-lymphocyte subpopulations and B7-H1/PD-1 expression in nasal polyposis

T-lymphocyte subpopulations and B7-H1/programmed death-1 (PD-1) positive lymphocytes infiltrating nasal polyps were evaluated in 17 patients with chronic sinusitis with nasal polyposis. Peripheral blood samples were also obtained from the patients and from 11 healthy controls. The CD4(+), CD8(+), CD3(+), CD19(+), B7-H1(+) and PD-1(+) lymphocyte populations were measured using flow cytometry. Lymphocytes from nasal polyps had significantly fewer CD4(+) but significantly more CD8(+) T-cells compared with lymphocytes from the peripheral blood of patients and controls. The percentages of CD19(+)/B7-H1(+) B-cells and of CD3(+)/PD-1(+) T-cells were significantly higher in the nasal polyp samples than in those from peripheral blood of patients and controls. Changes in the T-lymphocyte subpopulations and in the up-regulation of B7-H1 and PD-1 in lymphocytes infiltrating nasal polyps may be involved in the development of the chronic inflammation associated with nasal polyposis.

The anomalous deuterium isotope effect on the chemical shift of the bridge hydrogen in the enol tautomer of 2,4-pentanedione

The nature of the intramolecular hydrogen bond in the enol tautomer of 2,4-pentanedione has been investigated by high resolution proton and deuteron magnetic resonance spectroscopy. An unusually large deuterium isotope effect on the chemical shift of the bridge hydrogen has been observed. This unexpected result, together with the observation of a pronounced temperature dependence for both the proton and deuteron resonances, suggests that two states with different chemical shifts for the bridge hydrogen are involved in rapid equilibrium and that the anomalous deuterium isotope effect has its origin in the effect of deuterium substitution on the energy separation between these states. It is proposed that these states correspond to the symmetrical and asymmetrical structures of the intramolecular hydrogen bond.