Search

Thermoelectric (TE) metal oxides overcome crucial disadvantages of traditional heavy-metal-alloy-based TE materials, such as toxicity, scarcity, and instability at high temperatures. Here, we report the TE properties of metal oxide superlattices, composed from alternating layers of 5% Pr3+-doped SrTiO3−δ (SPTO) and 20% Nb5+-doped SrTiO3−δ (STNO) fabricated using pulsed laser deposition (PLD). Excellent stability is established for these superlattices by maintaining the crystal structure and reproducing the TE properties after long-time (20 h) annealing at high temperature (1000 K). The introduction of oxygen vacancies as well as extrinsic dopants (Pr3+ and Nb5+), with different masses and ionic radii, at different lattice sites in SPTO and STNO layers, respectively, results in a substantial reduction of thermal conductivity via scattering a wider range of phonon spectrum without limiting the electrical transport and thermopower, leading to an enhancement in the figure-of-merit (ZT). The superlattice composed of 20 SPTO/STNO pairs, 8 unit cells of each layer, exhibits a ZT value of 0.46 at 1000 K, which is the highest among SrTiO3-based thermoelectrics. [ABSTRACT FROM AUTHOR]

A new degradant of Nafcillin Sodium was found at a level of 1.8% w/w during the gradient reversed-phase HPLC analysis in stability storage samples. This impurity was identified by LC-MS and was characterized by 1H-NMR, 13C-NMR, LC/MS/MS, elemental analysis, and IR techniques. Based on the structural elucidation data, this impurity was named as N-[(2S)-2-carboxy-2-{[(2-ethoxynaphthalen- 1-yl)carbonyl]amino}ethylidene]-3-({N-[(2-ethoxynaphthalen-1-yl)- carbonyl]glycyl}sulfanyl)-D-valine. This impurity was prepared by isolation and was co-injected into the HPLC system to confirm the retention time. To the best of our knowledge, this impurity has not been reported elsewhere. The identification and structural elucidation of this degradant impurity has been discussed in detail. [ABSTRACT FROM AUTHOR]

In- and Yb-doped CoSb3 thin films were prepared by pulsed laser deposition. Process optimization studies revealed that a very narrow process window exists for the growth of single-phase skutterudite films. The electrical conductivity and Seebeck coefficient measured in the temperature range 300-700 K revealed an irreversible change on the first heating cycle in argon ambient, which is attributed to the enhanced surface roughness of the films or trace secondary phases. A power factor of 0.68Wm-1 K-1 was obtained at ~700 K, which is nearly six times lower than that of bulk samples. This difference is attributed to grain boundary scattering that causes a drop in film conductivity. [ABSTRACT FROM AUTHOR]

Objectives: Mosquito densonucleosis viruses (DNVs) are known to persistently infect the insect cell line and mosquito population in nature, causing mortality in mosquitoes. Here we report the isolation and characterization of a DNV from Aedes aegypti and its distribution among different Ae. aegypti populations from India. Methods: We screened Ae. aegypti mosquito populations from different states of India by PCR. Virus isolation and purification was performed using a cesium chloride gradient from a positive mosquito colony. Characterization of this isolate was carried out by electron microscopy, Western blot and sequencing. Results: Electron microscopy showed the presence of parvovirus-like particles, and Western blot showed the presence of 2 viral proteins of 40 and 41 kDa. A total of 3,776 bases of genome were sequenced, which included a 3′UTR of 128 bases, a coding region of 3,507 bases and a 5′UTR of 141 bases. Three open reading frames (ORFs) were identified and characterized. The NIVDNV genome showed 95% similarity with Culex pipiens pallens DNV and 93% similarity with Ae. aegypti DNV. Conclusion: Phylogenetic analysis of all 3 ORFs showed that this new isolate falls in the lineage of Brevidensovirus along with other mosquito DNVs. Copyright © 2009 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

We sought to evaluate the biological function of the receptor tyrosine kinase EphB4 in bladder cancer. All of the nine bladder cancer cell lines examined express EphB4 and the receptor could be phosphorylated following stimulation with its cognate ligand, EphrinB2. Out of the 15 fresh bladder cancer specimens examined, 14 expressed EphB4 with a mean sevenfold higher level of expression compared to adjacent normal urothelium. EphB4 expression was regulated by several mechanisms: EPHB4 gene locus was amplified in 27% tumor specimens and 33% cell lines studied; inhibition of EGFR signaling downregulated EphB4 levels; and forced expression of wild-type p53 reduced EphB4 expression. EphB4 knockdown using specific siRNA and antisense oligodeoxynucleotides molecules led to a profound inhibition in cell viability associated with apoptosis via activation of caspase-8 pathway and downregulation of antiapoptotic factor, bcl-xl. Furthermore, EphB4 knockdown significantly inhibited tumor cell migration and invasion. EphB4 knockdown in an in vivo murine tumor xenograft model led to a nearly 80% reduction in tumor volume associated with reduced tumor proliferation, increased apoptosis and reduced tumor microvasculature. EphB4 is thus a potential candidate as a predictor of disease outcome in bladder cancer and as target for novel therapy.Oncogene (2006) 25, 769–780. doi:10.1038/sj.onc.1209108; published online 3 October 2005 [ABSTRACT FROM AUTHOR]

In the present study, comparative analysis of glass ionomer and nanofillers in the performance of dental composite has been reviewed. In dental composite, a number of particulate fillers specifically nanoparticle are being tested and used. A new approach has been tried and investigated to replace expensive nanofillers with the other filler such as glass ionomer. There is a strong need to understand the scientific method, to conduct the clinical trial, and to perform the laboratory test to evaluate role of each parameter, constituent in the performance of dental composite. The present research reviewed the recent finding, possible opportunity and challenges for use of glass ionomer as replacement of nanofiller in dental composite. The existing literature on the favorable and non‐favorable side of glass ionomer is critically evaluated. The major aspect considered in the present review was to evaluate the surface roughness, mechanical properties and wear properties. The present article attempted to provide a state‐ of‐ the‐art analysis of fabrication method, surface treatment method and comparative analysis on role of particulate filler versus glass ionomer on the performance based on mechanical and wear testing mechanism. [ABSTRACT FROM AUTHOR]

Murine leukemia virus (MuLV)-derived retroviral vectors have had limited application in vascular gene therapy because of low transduction efficiency of vascular tissues, both in vitro and in vivo. In this study, we compared the gene transfer efficiency of two retroviral vectors: amphotropic MuLV and a MuLV vector pseudotyped with the vesicular stomatitis virus G glycoprotein (VSV-G) envelope. Target vascular tissues included human endothelial cells (EC), smooth muscle cells (SMC) and saphenous veins (SV). Transduction efficiency of human EC and SMC was significantly higher for VSV-G pseudotyped MuLV vector (90%) than for Amphotropic MuLV (20%). Luminal surface en face analysis of transduced cultured SV showed a six- to 10-fold greater transduction efficiency with VSV-G pseudotyped MuLV. The tissue plasminogen activator (tPA) gene was transduced into EC using each vector. Four days following transduction, a 12-fold higher tPA antigen concentration and a 38-fold higher tPA enzymatic activity was measured from cells transduced with the VSV-G pseudotyped vectors as compared with the amphotropic MuLV. There was no detectable pseudotransduction (protein transfer) associated with the VSV-G MuLV vector. Both AZT inhibition of reverse transcriptase and cell division arrest by gamma irradiation inhibited transduction, indicating that viral transduction correlated with RNA reverse transcription and cell proliferation. MuLV pseudotyped with the VSV-G envelope glycoprotein is an effective retroviral vector for vascular gene therapy. [ABSTRACT FROM AUTHOR]

In this paper we investigate the problem of computing the maximum number of entries which can be added to a partially filled latin square. The decision version of this question is known to be NP-complete. We present two approximation algorithms for the optimization version of this question. We first prove that the greedy algorithm achieves a factor of 1/3. We then use insights derived from the linear relaxation of an integer program to obtain an algorithm based on matchings that achieves a better performance guarantee of 1/2. These are the first known polynomial-time approximation algorithms for the latin square completion problem that achieve nontrivial worst-case performance guarantees. Our study is motivated by applications to lightpath assignment and switch configuration in wavelength routed multihop optical networks. [ABSTRACT FROM AUTHOR]

Iron alloy based amorphous coating materials have enormous potential in wide range of applications such as petrochemical, aerospace, ocean, and electronic communications due to their better mechanical properties, chemical properties, magnetic properties and tribological properties. The industrial applications of coating are increasing rapidly due to many advancements in the material development and coating deposition techniques. The present paper reviewed the recent progresses in deposition technologies, development of new high order alloys and composite based coating materials. In this regard, change in microstructure, elemental composition, mechanical and tribological properties on performance of iron alloy based coating properties were presented. It can be concluded that the tribological properties of coating is dependent on pre‐coating and post‐coating factors. Pre‐coating factors include coating deposition techniques, coating layer thickness and coating parameters such as spray distance, oxygen flow rate etc. Post‐coating factors include microstructure, hardness, fracture toughness and adhesion strength. Therefore, multi‐criteria decision making techniques can be the best approach to find the optimum formulation of coating materials to achieve desired set of objectives under the conflicting criteria. [ABSTRACT FROM AUTHOR]

The results of field experiment conducted during 2003-04 and 2004-05 revealed that green and dry fodder yield of sorghum were highest when the crop received recommended dose of fertilizer (RDF) at 60 kg N+30 kg P2O5 ha-1, but the crop yielded comparable green and dry fodder when it received half RDF (30 kg N+15 kg P2O5 ha-1) +biofertilizers (Azotobacter+phosphate solubilizing bacteria). Further, RDF and half RDF+biofertilizers enhanced the dry fodder yield by 45.8 and 41.2%, respectively over control. The highest agronomic efficiency (57 kg dry fodder kg-1 N applied), net return (INR 5190 ha-1) and benefit-cost ratio (1.45) were also obtained with half RDF+biofertilizers. On the contrary, the crop removed significantly greater amount of N and P when supplied with RDF, while RDF and half RDF+biofertilizers were at par and significantly superior to half RDF and control in respect of K uptake. RDF (80 kg N+40 kg P2O5 ha-1) applied to preceding mustard significantly out yielded all other treatments in respect of green fodder yield of sorghum barring residual half RDF+biofertilizers. Residual RDF and half RDF+biofertilizers enhanced dry fodder yield by 31.6 and 27.0%, respectively. [ABSTRACT FROM AUTHOR]

Cadmium Zinc Telluride (CdZnTe) is a ternary Ⅱ- Ⅵ undeviating band gap semiconductor with cubic Zinc blende formation and it is a propitious material for ambient temperature xray as well as gamma ray sensor detectors. Cadmium Zinc Telluride (CdZnTe) thin layer coating were developed on nickel substrate by chemical bath deposition in non-aqueous approach. The as grown films were inspected by X-ray diffraction (XRD), Field emission scanning electron microscope (FESEM), Scanning electron microscope, Fourier transform infrared spectroscopy (FTIR), PL spectra, UV spectra, Raman spectroscopy and Four- Probe analysis. Studies tell that as grown films are poly-crystalline in nature along with cubic zinc blende formation. The structural properties like crystallite size, lattice constant, micro strain as well as dislocation density were evaluated. FESEM and SEM analysis reveals that the as developed films are smooth and equal sized uniform spherical grains distributed in single state as well as in cluster form. The average size of grain film is observed to be 12.33 nm. Optical study reveals the broad transmittance escorted by the band gap energy of 2.2eV. Electrical study reveals that resistivity of as grown film is 5.1×105 Ω-cm at room temperature. [ABSTRACT FROM AUTHOR]

Zinc Cadmium Sulphide (ZnCdS) is a ternary direct band gap semiconducting material having potential applications in different opto-electronic devices. The deposition temperature can be effectively used to enhance the structure and optical properties of the films. In this paper, we have investigated the effect of air annealing on the various properties of ZnCdS films. A nanocrystalline ZnCdS thin film was successfully deposited on molybdenum substrate and the effect of annealing on structural, morphological, and optical properties were studied. The main impact was found to be slightly increase in crystallite size which effectively reduced the defects. It is observed that deposited film annealed at higher temperature provide a smooth and flat texture suited for optoelectronic applications. SEM photographs reveals the deposited grains are well connected and uniformly distributed over the surface. The experimental results show that the energy gap of the films is not much affected by the annealing temperature and varies from 2.6 eV to 2.7 eV. However, the oxygen annealing improves crystalline structure. [ABSTRACT FROM AUTHOR]

The present work focuses on the effect of annealing heat treatment on the microstructure, mechanical and erosion properties of iron alloy based coatings with varying chromium content. High velocity oxygen fuel coating method was used to deposit the coating over the substrate material 316 L stainless steel. The study was done in terms of microstructural analysis using x-ray diffractometer, surface and cross-sectional morphology using field emission scanning electron microscope, mechanical and erosion wear analysis. It was found that x-ray diffractometer indicated presence of less amount of titanium dioxide (TiO2) and silicon dioxide (SiO2) after heat treatment. However, the peaks of hardened phase of diironylidenetitanium (Fe2Ti) and iron-chromium (Fe-Cr) was increased. Addition of chromium up to 10 wt. % improved the hardness and adhesion pull of strength by 16 % and 62 % respectively. On the other side heat treatment of iron alloy based coating having 10 wt. % chromium increased the hardness and adhesion pull off strength by 17.3 % and 35 % respectively. The erosion wear rate was also decreased with the annealing process. The study shows that the annealing process increases hardness and adhesion pull off strength but decreases porosity and erosion wear rate. [ABSTRACT FROM AUTHOR]

A late preterm male infant was admitted to the neonatal intensive care unit with an asymmetric chest wall and a herniating mass through the left second intercostal space on crying. On auscultation, the heart sounds were audible on the right side of the chest. Systemic examination was otherwise unremarkable. A roentgenogram of the chest revealed dextro position of heart and hyperlucent left lung fields. Echocardiogram showed heart on the right with a structurally normal heart. A clinical diagnosis of Poland's syndrome was made based on the hypoplasia of the left pectoral muscles, ribs and nipple, dextroposition of heart and lung herniation. His clinical course was uneventful and doing remarkably well on follow up. [ABSTRACT FROM AUTHOR]

The field of 4D printing has emerged as a promising technology in the realm of implantable medical devices. Unlike traditional 3D printing, 4D printing allows for the fabrication of materials that can change shape or function over time in response to external stimuli. This review paper provides an overview of the application of 4D printing in implantable medical devices, highlighting its potential benefits, challenges, and future directions. This paper provide an overview of 4D printing, exploring the application of 4D printing in implantable medical devices and discuss the advantages and challenges of 4D‐printed implants. These advantages may include patient‐specific customization, enhanced functionality and performance, and minimally invasive procedures. Additionally, the paper addresses the challenges and future prospective associated with material selection, fabrication techniques, scalability, and regulatory and ethical considerations in the context of 4D printing. By addressing these topics, this review paper aims to provide a comprehensive understanding of the application of 4D printing in implantable medical devices. It seeks to contribute to the existing body of knowledge in the field and inspire further research and innovation in this promising area of healthcare technology. [ABSTRACT FROM AUTHOR]

Energy systems that rely on non-renewable sources like fossil fuels are contributing to climate change by emitting more carbon dioxide. It is crucial to shift towards renewable energy sources such as solar, wind, biomass, and geo-thermal to meet our energy needs. Organic Rankine Cycle (ORC) is a thermodynamic cycle which utilizes an organic fluid with higher molecular mass and lower vaporization temperature than water-like organic fluids such as refrigerants. ORC technology powered by solar energy and waste heat plays an essential role in reducing carbon emission impact. It is becoming one of the most promising approaches to recovering waste heat using regenerative cycles. In this work, ORC driven by solar energy was performed in CYCLE tempo. The heat from solar panels was given as an input to run the ORC power system in the primary circuit. The system involves an evaporator, steam turbines (high pressure and low pressure), a condenser, a feed pump, a waste heat source and R134a as the working fluid for the primary ORC. In the secondary circuit, R245fa was used to produce additional power. Hence, the total power produced by the integration of these two circuits was 5.114 MW and a share of total electricity was utilized for hydrogen production by reversible fuel cells (i) Solid Oxide Electrolysis Fuel Cell (SOEFC) and (ii) Proton Exchange Membrane Fuel Cell (PEMFC). They also compared the results of these fuel cells. The net power of 3.114 MW was available to meet local energy demands as well. [ABSTRACT FROM AUTHOR]