Rietveld analysis of CaCu<Subscript>3</Subscript>Ti<Subscript>4</Subscript>O<Subscript>12</Subscript> thin films obtained by RF-sputtering

Calcium copper titanate, CaCu₃Ti₄O₁₂, CCTO, thin films with polycrystalline nature have been deposited by RF sputtering on Pt/Ti/SiO₂/Si (100) substrates at a room temperature followed by annealing at 600 °C for 2 h in a conventional furnace. The crystalline structure and the surface morphology of the films were markedly affected by the growth conditions. Rietveld analysis reveal a CCTO film with 100 % pure perovskite belonging to a space group Im3 and pseudo-cubic structure. The XPS spectroscopy reveal that the in a reducing N₂ atmosphere a lower Cu/Ca and Ti/Ca ratio were detected, while the O₂ treatment led to an excess of Cu, due to Cu segregation of the surface forming copper oxide crystals. The film present frequency -independent dielectric properties in the temperature range evaluated, which is similar to those properties obtained in single-crystal or epitaxial thin films. The room temperature dielectric constant of the 600-nm-thick CCTO films annealed at 600 °C at 1 kHz was found to be 70. The leakage current of the MFS capacitor structure was governed by the Schottky barrier conduction mechanism and the leakage current density was lower than 10^?7 A/cm² at a 1.0 V. The current–voltage measurements on MFS capacitors established good switching characteristics.     

Optimized contrast enhancement for real-time image and video dehazing

A fast and optimized dehazing algorithm for hazy images and videos is proposed in this work. Based on the observation that a hazy image exhibits low contrast in general, we restore the hazy image by enhancing its contrast. However, the overcompensation of the degraded contrast may truncate pixel values and cause information loss. Therefore, we formulate a cost function that consists of the contrast term and the information loss term. By minimizing the cost function, the proposed algorithm enhances the contrast and preserves the information optimally. Moreover, we extend the static image dehazing algorithm to real-time video dehazing. We reduce flickering artifacts in a dehazed video sequence by making transmission values temporally coherent. Experimental results show that the proposed algorithm effectively removes haze and is sufficiently fast for real-time dehazing applications.     

The ITU-T Software Tool Library

The advancement of speech coding technology has led to new and improved standards. The Telecommunication Standardization Sector of the International Telecommunication Union (ITU-T) has been a leader in developing speech coding standards for telecommunications applications. To increase the efficiency of the coding standard selection process, a group called User's Group on Software Tools (UGST) was established in 1990 to produce a framework of speech coding-related software tools that would allow a common ground for activities across different organizations. Over the years, this group produced a high-quality software tool library (STL), which has been used in the definition of ITU and non-ITU standards, such as G.723.1, G.729, half-rate and enhanced full-rate GSM, among others. However, despite its usefulness, the ITU-T STL is largely unknown outside the telecommunications standards community. This paper introduces the ITU-T STL concepts and functionalities to the wider communications community.     

Cloning and characterization of arylamine N-acetyltransferase genes from Mycobacterium smegmatis and Mycobacterium tuberculosis: increased expression results in isoniazid resistance

Arylamine N-acetyltransferases (NATs) are found in many eukaryotic organisms, including humans, and have previously been identified in the prokaryote Salmonella typhimurium. NATs from many sources acetylate the antitubercular drug isoniazid and so inactivate it. nat genes were cloned from Mycobacterium smegmatis and Mycobacterium tuberculosis, and expressed in Escherichia coli and M. smegmatis. The induced M. smegmatis NAT catalyzes the acetylation of isoniazid. A monospecific antiserum raised against pure NAT from S. typhimurium recognizes NAT from M. smegmatis and cross-reacts with recombinant NAT from M. tuberculosis. Overexpression of mycobacterial nat genes in E. coli results in predominantly insoluble recombinant protein; however, with M. smegmatis as the host using the vector pACE-1, NAT proteins from M. tuberculosis and M. smegmatis are soluble. M. smegmatis transformants induced to express the M. tuberculosis nat gene in culture demonstrated a threefold higher resistance to isoniazid. We propose that NAT in mycobacteria could have a role in acetylating, and hence inactivating, isoniazid.     

Bone tumors of the coracoid process of the scapula

Bone tumors of the coracoid process of the scapula are rare, and diagnosis and treatment often are delayed. The records of 18 patients with bone tumors of the coracoid process were reviewed. Histologic types included eight cases of ordinary chondrosarcoma, three cases of dedifferentiated chondrosarcoma, two cases of osteoid osteoma, and one case each of osteosarcoma, plasmacytoma, lymphoma, giant cell tumor, and aneurysmal bone cyst. All 18 patients had shoulder pain, and eight of them had been treated with steroid injections for nonneoplastic conditions. Radiologically, chondrosarcoma did not always show clear cortical destruction, and one giant cell tumor had features mimicking those of chondrosarcoma. Five patients (three with dedifferentiated chondrosarcoma, one with chondrosarcoma, one with plasmacytoma) died of disease. The coracoid process was the site with a markedly high proportion of chondrosarcomas. Bone tumors of the coracoid process may be difficult to detect on plain radiographs. In the patient with persistent shoulder pain unresponsive to the selected treatment, additional imaging studies should be considered to eliminate the possibility of a bone lesion.     

Analysis and prevention of DRAM latch-up during power-on

The occasional power-on latch-up phenomenon of DRAM modules with a data bus shared by multiple DRAM chips on different modules was investigated and the circuit techniques for latch-up prevention were presented. Through HSPICE simulations and measurements, the latch-up triggering source was identified-to be the excessive voltage drop at the n-well pick-up of the CMOS transmission gate of read data latch circuit due to the short-circuit current which flows when the bus contention occurs during power-on. By extracting the HSPICE Gummel-Poon model parameters of the parasitic bipolar transistors of DRAM chips from the measured I-V and C-V data, HSPICE simulations were performed for the power-on latch-up phenomenon of DRAM chips. Good agreements were achieved between measured and simulated voltage waveforms. In order to prevent the power-on latch-up even when the control signals (RAS, GAS) do not track with the power supply, two circuit techniques were presented to solve the problem. One is to replace the CMOS transmission gate by a CMOS tristate inverter in the DRAM chip design and the other is to start the CAS-BEPORE-RAS (CBR) refresh cycle during power-on and thus disable all the Dout buffers of DRAM chips during the initial power-on period     

The production of macrophage inflammatory protein-1 alpha by human basophils

Macrophage inflammatory protein-1alpha (MIP-1alpha) has previously been shown to be produced by mononuclear cells, eosinophils, and neutrophils. Its production by basophils has not been investigated. The objective of this study was to investigate the production of MIP-1alpha by basophils. Peripheral blood basophils were separated by Percoll gradient centrifugation, cultured overnight, and processed for double immunocytochemistry using Abs against MIP-1alpha and FcepsilonRIalpha (alpha subunit of IgE receptor type 1). We demonstrated that basophils expressed immunoreactive MIP-1alpha upon stimulation with anti-IgE. Less than 5% of the basophils stained for MIP-1alpha without stimulation. The secretion of MIP-1alpha by basophils was studied by ELISA. In these experiments, basophils were further enriched to 65 to 99% (median, 86%) by a negative selection method. Basophils released MIP-1alpha when stimulated by Abs against IgE and FCepsilonRIalpha as well as IL-3 and the calcium ionophore, A23187. In parallel experiments, PBMC, eosinophils, and neutrophils did not produce MIP-1alpha in response to anti-IgE, but they did so in response to A23187. No MIP-1alpha release was detected in platelet preparations. Preincubation with IL-3 (15 min or 18 h) augmented anti-IgE-included basophil MIP-1alpha production. The secretion of MIP-1alpha by basophils was detectable shortly after stimulation and gradually increased over 24 h. Since MIP-1alpha has potent inflammatory and histamine-releasing activities, its production by basophils may indicate a positive feedback mechanism for allergic inflammation.     

Shelf-life of prepeeled potato cultivated, stored, and processed by various methods

The present study was aimed to investigate the effects of indigestible dextrin and polydextrose, soluble dietary fibers with low molecular weight, on lipid metabolism and disaccharidase activities of intestinal mucosa in rats fed a high sucrose diet. Their effects were compared with those of well-known soluble fibers, pectin, and guar gum, and also with an insoluble fiber, cellulose. Dietary fibers added to diets at the 5% (w/w) level were alpha-cellulose, pectin, guar gum, indigestible dextrin, and polydextrose. Male Sprague-Dawley rats were given free access to test diets for 6 weeks. Body weight gain was the lowest in rats fed guar gum, the highest in rats fed cellulose, and in-between in rats fed other diets. Although guar gum, pectin, and indigestible feeding dextrin had lower plasma lipid values than cellulose feeding did, the differences were statistically insignificant. Liver triglyceride of the guar gum-fed group was about a third that of the cellulose-fed group, but although those of rats fed polydextrose, indigestible dextrin, and pectin were lower than that of cellulose, the differences were insignificant. Liver cholesterol and phospholipid concentrations were similar among groups. Daily fecal excretion of total lipid, cholesterol, and bile acids were highest in rats fed guar gum, followed by pectin-fed and cellulose-fed rats, and the lowest in rats fed indigestible dextrin and polydextrose. Jejunal sucrase activity was low in the order of guar-gum, polydextrose, indigestible dextrin, pectin, and cellulose. The results indicate that the hypolipidemic effect of soluble dietary fibers would be lessened with reduction in molecular weight, but that the lower sucrase activity by soluble fibers with low molecular weight might be beneficial for hypoglycemic effect.