Laser sensor for detection of SF6 leaks in high powerinsulated switchgear systems

A novel photoacoustic spectrometer (PA) has been developed for in-situ detection of SF₆ leaks in low concentrations. The developed system is equipped with a sound alarm system and has been tested in the laboratory for very minute SF₆ leaks. This newly developed SF₆ detection device utilizes a high quality factor resonant photoacoustic cell and continuous wave (CW) line tunable CO₂ laser at 10.55 μm wavelength. Whenever SF₆ is detected an acoustic signal is generated and no signal appears from ambient air if there is no leakage of SF₆. An electret microphone is used for the detection of these acoustic signals. The system is capable of detecting leaks of the order of 3.5 ppbv (parts per billion by volume) concentration. This device has been proved to have significant applications to industrial organizations that have electric power gas insulated systems (GIS). It could be also applied for other applications such as monitoring of environmental pollutants with minimal adjustments     

XR-C1, a new CHO cell mutant which is defective in DNA-PKcs, is impaired in both V(D)J coding and signal joint formation

DNA-dependent protein kinase (DNA-PK) plays an important role in DNA double-strand break (DSB) repair and V(D)J recombination. We have isolated a new X-ray-sensitive CHO cell line, XR-C1, which is impaired in DSB repair and which was assigned to complementation group 7, the group that is defective in the XRCC7 / SCID ( Prkdc ) gene encoding the catalytic subunit of DNA-PK (DNA-PKcs). Consistent with this complementation analysis, XR-C1 cells lackeddetectable DNA-PKcs protein, did not display DNA-PK catalytic activity and were complemented by the introduction of a single human chromosome 8 (providing the Prkdc gene). The impact of the XR-C1 mutation on V(D)J recombination was quite different from that found in most rodent cells defective in DNA-PKcs, which are preferentially blocked in coding joint formation, whereas XR-C1 cells were defective in forming both coding and signal joints. These results suggest that DNA-PKcs is required for both coding and signal joint formation during V(D)J recombination and that the XR-C1 mutant cell line may prove to be a useful tool in understanding this pathway.     

The univector plasmid-fusion system, a method for rapid construction of recombinant DNA without restriction enzymes

BACKGROUND:. Modern biological research is highly dependent upon recombinant DNA technology. Conventional cloning methods are time-consuming and lack uniformity. Thus, biological research is in great need of new techniques to rapidly, systematically and uniformly manipulate the large sets of genes currently available from genome projects. RESULTS:. We describe a series of new cloning methods that facilitate the rapid and systematic construction of recombinant DNA molecules. The central cloning method is named the univector plasmid-fusion system (UPS). The UPS uses Cre-lox site-specific recombination to catalyze plasmid fusion between the univector - a plasmid containing the gene of interest - and host vectors containing regulatory information. Fusion events are genetically selected and place the gene under the control of new regulatory elements. A second UPS-related method allows for the precise transfer of coding sequences only from the univector into a host vector. The UPS eliminates the need for restriction enzymes, DNA ligases and many in vitro manipulations required for subcloning, and allows for the rapid construction of multiple constructs for expression in multiple organisms. We demonstrate that UPS can also be used to transfer whole libraries into new vectors. Additional adaptations are described, including directional PCR cloning and the generation of 3' end gene fusions using homologous recombination in Escherichia coli. CONCLUSIONS:. Together, these recombination-based cloning methods constitute a new comprehensive approach for the rapid and efficient generation of recombinant DNA that can be used for parallel processing of large gene sets, a feature that will facilitate future genomic analysis.     

Effects of dietary vegetable oils on behavior and drug responses in mice

Previously, we noted significant differences in the behavioral patterns of mice fed safflower oil with a very low alpha-linolenate/linoleate ratio and perilla oil with a high alpha-linolenate/linoleate ratio from mothers to offsprings. In this report, we compared the behavior and drug responses in mice fed diets containing six different vegetable oils-corn, rapeseed, soybean, safflower, perilla and a mixture of perilla and safflower oils- for a relatively short period: 8 months after weaning. Soybean oil is a component of most conventional diets and was used as a control. The alpha-linolenate/linoleate ratios of the oils appeared to affect the locomotor activities in a wheel cage: the activity decreased in the order of safflower, the mixture (1:1) and the perilla oil groups. However, the rapeseed oil group exhibited much higher locomotor activity than that expected from the alpha-linolenate/linoleate ratio. Additionally, the rapeseed oil group exhibited unusual behavior patterns, including higher ambulation and rearing activities, faster acquisition of the water maze task and slower habituation behavior as compared with the control group. Susceptibility to pentobarbital anesthesia tended to be higher in the rapeseed oil group. The differences in the alpha-linolenate/linoleate ratios of these oils alone do not account for the observed differences in the behavioral patterns among the six dietary groups. Although we cannot exclude the possibility that the observed behavioral anomaly is due to the unique fatty acid composition of rapeseed oil, we speculate that a factor(s) other than fatty acids in rapeseed oil affected nervous system functions.     

Effects of injectio reduqing on plasma IL-8 and nitric oxide levels in rabbits with endotoxin induced disseminated intravascular coagulation

Experiments were performed for investigating the effects of Injectio Reduqing (RDQ) on plasma interleukin-8 (IL-8), NO2-/NO3-, complement 5a(C5a) and polymorphonuclear neutrophilic leukocyte (PMN) Chemotaxis Index (CI) in rabbits with endotoxin-induced disseminated intravascular coagulation (DIC). The results showed that plasma IL-8, NO2-/NO3-, C5a and CI levels of PMN increased markedly in model group, which were confirmed pathologically with obvious damage of tissues or organs. While in RDQ group the abov-mentioned parameters and damage of tissues or organs were reduced significantly (P < 0.01). The results suggested that the IL-8 and NO might be involved in pathogenesis of endotoxin-induced DIC, and RDQ could be used in preventing or treating DIC through mechanism of regulation of cytokines network.     

Line matching of wide baseline images in an affine projection space

ABSTRACT

Line matching plays an important role in vision localization and three-dimensional reconstruction of building structures. The conventional method of line matching is not effective for processing stereo images with wide baselines and large viewing angles. This paper proposes a line matching method in an affine projection space, aiming to solve the problem of change of viewing angles in aerial oblique images. Firstly, monocular image orientation can be performed through geometric structures of buildings. Secondly, according to the pose information of the camera, the affine projection matrix is obtained. The original image can be rectified as a conformal image based on this projection matrix, thereby reducing the difference in the viewing angle between images. Then, line matching is performed on the rectified images to get the matched line pairs. Finally, the inverse affine projection matrix is used to back-project the matched line pairs to the original images. The experimental results of five groups of aerial oblique images show that the matched line segments obtained by the proposed method are basically superior to those of the methods which are directly processed on the original image in terms of quantity, correctness, and efficiency.     

Determination of Acid Number of Biodiesel and Biodiesel Blends

Due to an increase in the commercial use of biodiesel and biodiesel blends, both ASTM D 6751 and EN 14214 include the acid number (AN) as an important quality parameter. It was found that determination of AN of biodiesel and biodiesel blends using the ASTM D 974 results in large values of repeatability (up to 73.41%) and larger percentage error (up to 42.88%). Therefore, ASTM D 974 has been modified using a lower concentration of base (0.02 M KOH instead of 0.1 M KOH) as well as reducing the amount of toxic titration solvent from 100 mL to only 10 mL. This makes the modified ASTM D 974 as a green analytical method which uses a reduced amount of toxic solvent. This modified method significantly reduced the maximum percentage error from 42.88 to 5.92%. The application of this modified ASTM D 974 for the determination of AN of biodiesel and biodiesel blends was studied. The accuracy of this modified ASTM D 974 for biodiesel (B100) was measured to be within 3.51% over the AN range of 0.313–0.525 mg KOH/g and maximum repeatability was decreased from 8.37 to 2.75% within this AN range which is far below the ASTM D 974 stated repeatability specifications. For B20, B10, B5, B2, and B1, the most accurate values were measured at AN values of 0.177, 0.067, 0.072, 0.126, and 0.096 mg KOH/g, respectively. Excellent linearity values of R ² for calculated and experimentally determined AN were obtained. The difference between the experimental and the calculated AN for all biodiesel and biodiesel blend samples was within ± 0.018 mg KOH/g. This extensive study has demonstrated that this modified ASTM D 974 is a reliable method for the determination of AN and could be used for establishing the specifications of AN for biodiesel and biodiesel blends ranging from B1 to B20 in quality standards.     

Evaluation of toxic elements in baby foods commercially available in Pakistan

In present work, the concentrations of toxic elements, aluminium (Al), cadmium (Cd), nickel (Ni) and lead (Pb) were measured in different solid baby foods (BFs), primarily to evaluate whether the intakes comply within permissible levels of these toxic elements (TEs). The BFs were evaluated for total contents of TEs, using a simple and fast ultrasound-assisted extraction (UAE) method. The accuracy of the proposed UAE method was ensured by using certified reference materials and results obtained by conventional wet acid digestion method on same CRM, at 95% confidence level. The range of the investigated TEs in different BFs were 4770–35,200, 25.6–88.3, 124–332 and 52.5–90.6 μg/kg for Al, Cd, Ni and Pb, respectively. The results indicated that BFs including rice cereals have high level of all four TEs. The daily intakes of TEs for children through BFs have also been estimated, and are well below the recommended tolerable levels.     

Clinical manifestations and treatment of intestinal dysbacteriosis in patients with Flexner's dysentery

Flexner's dysentery is often accompanied with intestinal dysbacteriosis. Disbiotic changes in the intestine contribute to specific shigella endotoxins entering blood flow thus prolonging clinical symptoms of the underlying disease. Administration of bacterial biological preparations (bifidumbacterin forte, lactobacterin) relieves specific endotoxemia, reduces the duration of the disease and has an immunomodulating action.     

Experimental studies on the instabilities of viscous fingering in a Hele-Shaw cell

When air is injected into silicone oil contained in a horizontal Hele-Shaw cell, a single air bubble forms and grows showing various interesting phenomena. In this study the effects of the bubble front velocity, air injection velocity at a nozzle, fluid properties and cell depth on the stability of the growing bubble were investigated experimentally. By using the modified capillary number involving the aspect ratio, we obtained the onset conditions of the unstable bubble. Also, the bubble width was analyzed both quantitatively and qualitatively. Before the bubble experiences splitting, the bubble front velocity is almost proportional to the air injection velocity. Therefore the latter velocity may be used in a practical sense.