Dielectric Response of Sr Doped CaCu₃Ti₄O₁₂ Ceramics

Ca1−xSrxCu3Ti4O12 (x=0, 0.1, and 0.2) ceramics were fabricated and their dielectric properties were investigated. It was found that the dielectric constant significantly decreased with the increase of Sr content at low temperature region (\u3c250 K) and remained almost unchanged at high temperature region (\u3e250 K). Three sets of relaxation peaks were observed in electric modulus plots, which were considered to be associated with grains, domain boundaries, and grain boundaries, respectively. Through the analysis of the heights and calculated activation energies of the relaxation peaks, it is strongly believed that the suppressed dielectric constant is related to the change of domain boundaries with Sr doping. ©2007 American Institute of Physic

Antiperovskite Li3OCl Superionic Conductor Films for Solid-State Li-Ion Batteries.

Antiperovskite Li3OCl superionic conductor films are prepared via pulsed laser deposition using a composite target. A significantly enhanced ionic conductivity of 2.0 × 10-4 S cm-1 at room temperature is achieved, and this value is more than two orders of magnitude higher than that of its bulk counterpart. The applicability of Li3OCl as a solid electrolyte for Li-ion batteries is demonstrated

Combined effect of celecoxib and glucosamine sulfate on inflammatory factors and oxidative stress indicators in patients with knee osteoarthritis

Purpose: To investigate the combined effect of celecoxib and glucosamine sulfate on inflammatory factors and oxidative stress indicators in patients with knee osteoarthritis (KOA).Methods: Patients were randomly assigned to two groups of 60 patients each: control group and study group. The control group received celecoxib at a dose of 200 mg/kg/day, while the study group received glucosamine sulfate (500 mg/kg) in addition to celecoxib, thrice a day. Treatment in both groups lasted 8 weeks. The serum levels of tumor necrosis factor α (TNF-α), interleukin-1 (IL-1), prostaglandin-2 (PGE2), malondialdehyde (MDA), and activity of superoxide dismutase (SOD) were assayed before and after treatment. Visual analogue scale (VAS), osteoarthritis index, Lysholm knee score scale (LKSS), and adverse reactions were also evaluated.Results: After treatment, total effectiveness was significantly higher in the study group (91.33 %) than in control group (71.67 %, p < 0.05). Serum TNF-α, IL-1 and PGE2 were significantly lesser in the glucosamine sulfate-treated patients than in control group (p < 0.05). The activity of SOD was significantly higher in glucosamine sulfate-exposed patients than control patients (p < 0.05). On the other hand, VAS and WOMAC scores were markedly lower in patients given glucosamine sulfate than in control patients (p < 0.05).Conclusion: The combination of celecoxib with glucosamine sulfate effectively reduces immune inflammatory response, oxidative stress damage, and joint pain associated with KOA.Keywords: Celecoxib, Glucosamine sulfate, Osteoarthritis, Inflammatory factors, Oxidative stres

Selection of functional mutations in the U5-IR stem and loop regions of the Rous sarcoma virus genome

BACKGROUND: The 5' end of the Rous sarcoma virus (RSV) RNA around the primer-binding site forms a series of RNA secondary stem/loop structures (U5-IR stem, TψC interaction region, U5-leader stem) that are required for efficient initiation of reverse transcription. The U5-IR stem and loop also encode the U5 integrase (IN) recognition sequence at the level of DNA such that this region has overlapping biological functions in reverse transcription and integration. RESULTS: We have investigated the ability of RSV to tolerate mutations in and around the U5 IR stem and loop. Through the use of viral libraries with blocks of random sequence, we have screened for functional mutants in vivo, growing the virus libraries in turkey embryo fibroblasts. The library representing the U5-IR stem rapidly selects for clones that maintain the structure of the stem, and is subsequently overtaken by wild type sequence. In contrast, in the library representing the U5-IR loop, wild type sequence is found after five rounds of infection but it does not dominate the virus pool, indicating that the mutant sequences identified are able to replicate at or near wild type levels. CONCLUSION: These results indicate that the region of the RNA genome in U5 adjacent to the PBS tolerates much sequence variation even though it is required for multiple biological functions in replication. The in vivo selection method utilized in this study was capable of detecting complex patterns of selection as well as identifying biologically relevant viral mutants

Bonding and high-temperature reliability of NiFeMo alloy/n-type PbTe joints for thermoelectric module applications

PbTe is an extremely important thermoelectric (TE) material, due to its high TE conversion efficiency. Consequently, our effort focuses on developing PbTe-based TE modules, which requires developing novel approaches for bonding metallic contacts to PbTe. In this study, Fe, Mo, and NiFeMo alloy foils were directly bonded to n-type PbTe using a rapid hot press at 600, 700, or 800 °C under a pressure of 40 MPa and for various holding times. We find that in the case of Fe and Mo, it is difficult to form a metallurgically bonded high strength joint with PbTe. However, we find that NiFeMo alloy does effectively bond to PbTe at 700 °C, but not at 600 °C. Significant liquid Pb, which might be due to the reaction of PbTe with Ni, is found that penetrates along the NiFeMo grain boundaries near NiFeMo/PbTe joints during bonding at 700 °C where the extent of liquid Pb penetration can be controlled with the time of bonding. Furthermore, the Seebeck coefficient of bulk PbTe with NiFeMo contacts is similar to that without NiFeMo contacts. Finally, the accelerated thermal aging of NiFeMo/PbTe elements at 600 °C for 240 h shows that the failure mechanism of NiFeMo/PbTe joints under operating conditions is the continued formation and penetration of eutectic liquid NiFeMo–PbTe and liquid Pb along the NiFeMo grain boundaries

Generative Adversarial Mapping Networks

Generative Adversarial Networks (GANs) have shown impressive performance in generating photo-realistic images. They fit generative models by minimizing certain distance measure between the real image distribution and the generated data distribution. Several distance measures have been used, such as Jensen-Shannon divergence, $f$-divergence, and Wasserstein distance, and choosing an appropriate distance measure is very important for training the generative network. In this paper, we choose to use the maximum mean discrepancy (MMD) as the distance metric, which has several nice theoretical guarantees. In fact, generative moment matching network (GMMN) (Li, Swersky, and Zemel 2015) is such a generative model which contains only one generator network $G$ trained by directly minimizing MMD between the real and generated distributions. However, it fails to generate meaningful samples on challenging benchmark datasets, such as CIFAR-10 and LSUN. To improve on GMMN, we propose to add an extra network $F$, called mapper. $F$ maps both real data distribution and generated data distribution from the original data space to a feature representation space $\mathcal{R}$, and it is trained to maximize MMD between the two mapped distributions in $\mathcal{R}$, while the generator $G$ tries to minimize the MMD. We call the new model generative adversarial mapping networks (GAMNs). We demonstrate that the adversarial mapper $F$ can help $G$ to better capture the underlying data distribution. We also show that GAMN significantly outperforms GMMN, and is also superior to or comparable with other state-of-the-art GAN based methods on MNIST, CIFAR-10 and LSUN-Bedrooms datasets.Comment: 9 pages, 7 figure