An automated radiopharmaceutical dispenser

Residential proximity to electrical power lines of different voltage in relation to childhood leukemia was investigated through a case-control study undertaken in Greece during 1993-1994. The study comprised 117 incident cases of childhood leukemia and 202 age-, gender- and place-of-residence-matched controls. Four measures of exposure to magnetic fields were developed, using data provided by the Public Power Corporation of Greece: Voltage (V) divided by the distance (d), V/d2, V/d3 and an adaptation of the Wertheimer-Leeper code. Conditional-logistic-regression modeling was used to adjust for potential confounding influences of 18 variables. No significant trends of childhood leukemia risk with increasing exposure levels were noted, nor were there statistically significant elevations of disease risk at the higher exposure levels in each measure of exposure. These results do not support a causal link between residential proximity to electrical high-voltage wires and childhood leukemia risk, but in themselves do not refute a weak empirical association.     

Apolipoprotein B and AI distributions in the United States, 1988-1991: results of the National Health and Nutrition Examination Survey III (NHANES III)

Serum apolipoproteins (apo) B and AI were measured in a probability sample of the noninstitutionalized US civilian population, ages > or = 4 years, which included non-Hispanic whites, non-Hispanic blacks, and Mexican-Americans. Apo B concentrations were the same in males and females, lower in black males than in other males, low in childhood (approximately 0.80 g/L) and increasing to approximately 1.2 g/L in adults, and higher in younger women on hormones. Apo AI was higher in females than males, higher in blacks than in others, remained constant from childhood to adulthood (approximately 1.35 g/L) in males, but increased with age (approximately 1.30 g/L to approximately 1.55 g/L) in females, and was higher in women taking hormones. These are the first national probability estimates of apo B and apo AI in the US and are referable to the WHO-IFCC First International Reference Materials for apo AI and B.     

Dynamics of the N-terminal alpha-helix unfolding in the photoreversion reaction of phytochrome A

Time-resolved circular dichroism spectroscopy in the far-UV spectral region was used to examine the intermediates of the phytochrome photoreversion reaction (Pfr --> Pr). Three intermediates, lumi-F (tau = 320 ns), meta-Fa (tau = 265 micros) and meta-Fb (tau = 5.5 ms), have been identified in a simple sequential kinetic photoreversion mechanism by absorption spectroscopy [Linschitz, H., Kasche, V., Butler, W. L., & Siegelman, H. W. (1966) J. Biol. Chem. 241, 3395-3403; Pratt, L. H., & Butler, W. L. (1968) Photochem. Photobiol. 8, 477-485; Burke, M., Pratt, D. C., & Moscowitz, A. (1972) Biochemistry 11, 4025-4031; Spruit, C. J. P., Kendrick, R. E., & Cooke, R. J. (1975) Planta (Berlin) 127, 121-132; Eilfeld, P., & Rüdiger, W. (1985) Z. Naturforsch. 40c, 109-114; Chen, E., Lapko, V. N., Lewis, J. W., Song, P.-S., & Kliger, D. S. (1996) Biochemistry 35, 843-850]. In order to correlate the unfolding of the N-terminal alpha-helical segment with one or more of the intermediate species, time-resolved methods were coupled with the structurally sensitive probe of CD in the far-UV spectral region. Analysis of the TRCD data associates the decrease in alpha-helical content that occurs upon formation of Pr with decay of the meta-Fa intermediate. This unfolding process occurs with a time constant of 310 +/- 125 micros, which is consistent with the 265-micros lifetime for meta-Fa.     

Enantioselective analysis of praziquantel in plasma samples

In prokaryotes, DnaK-DnaJ chaperon is involved in the protein degradation catalyzed by proteases La and ClpA/B complex as shown in E. coli. To extend this into eukaryotic cells, we examined the effects of hsp70 genes, SSA1 and SSB1, and DnaJ genes, SIS1 and YDJ1, on the growth of proteasome subunit mutants of the yeast S. cerevisiae. The results identified SSB1 and SIS1 as a pair of chaperon genes specifically involved in efficient protein turnover in the yeast, whose overexpression suppressed the growth defects caused by the proteasome mutations. Moreover, a single amino acid substitution in the putative peptide-binding site of SSB1 protein profoundly enhanced the suppression activity, indicating that the activity is mediated by the peptide-binding activity of this chaperon. Thus SSB1, with its partner DnaJ, SIS1, modulates the efficiency of protein turnover through its chaperon activity.     

Effect of dynamic cross-linking on mixing torque behavior and tensile yield behavior of isotactic polypropylene (iPP) / ethylene-propylene diene rubber (EPDM) /nitrile rubber (NBR) elastomeric blends

The mixing torque behavior of ter blends of isotactic-polypropylene (iPP) with ethylene-propylene diene rubber (EPDM)/Nitrile rubber (NBR) was studied with the help of Rheometer using resole type phenolic resin as a cross-linking agents. Systematic changes with varying blend composition were observed in stress-strain behavior in the yield region viz., width of yield peak, work of yield, yield stress and yield strain. Analysis of yield stress data was made on the basis of various mathematical expressions of first power and two-thirds power laws of blend composition dependence and the porosity model. It led to consistent result from the expressions about the variation of stress concentration effect in both uncross-linked and cross-linked blend systems. With the aid of scanning electron microscopy (SEM) shapes and sizes of dispersed elastomer phase (EPDM / NBR) domains at varying blend compositions were studied.     

Cuckoo search algorithm based satellite image contrast and brightness enhancement using DWT–SVD

This paper presents a new contrast enhancement approach which is based on Cuckoo Search (CS) algorithm and DWT-SVD for quality improvement of the low contrast satellite images. The input image is decomposed into the four frequency subbands through Discrete Wavelet Transform (DWT), and CS algorithm used to optimize each subband of DWT and then obtains the singular value matrix of the low-low thresholded subband image and finally, it reconstructs the enhanced image by applying IDWT. The singular value matrix employed intensity information of the particular image, and any modification in the singular values changes the intensity of the given image. The experimental results show superiority of the proposed method performance in terms of PSNR, MSE, Mean and Standard Deviation over conventional and state-of-the-art techniques.     

A Novel Approach to Predict Field Strength in the Shadow of a 3-D Building Scenario

A novel approach to predict field strength in the shadow of a 3-D building scenario is presented. The field strength predicted by the proposed model is compared with available measurements and earlier predicted fields based on Fresnel-Kirchhoff theory. Two different scenarios have been considered to validate our model. The proposed model gives an improvement of 7.7 dB for Scenario 1; and 5.8 dB for Scenario 2. A good agreement between the prediction and the measurement is also observed.     

Riboflavin-mediated delivery of a macromolecule into cultured human cells

The effects of perivascular nerve stimulation and phenylephrine on osmolyte release were studied in the intact perfused rat liver and isolated liver parenchymal cells (PC) and nonparenchymal cells. In the perfused liver, electrical stimulation of perivascular nerves (20 Hz/2 ms/20 V) led to a phentolamine-sensitive increase of cell hydration by 6.5% +/- 1.2% (n = 3) and a transient phentolamine-sensitive stimulation of taurine and inositol, but not betaine, release. These nerve effects were mimicked by phenylephrine, but not prostaglandin F2alpha, and were not affected by sodium nitroprusside (SNP) or ibuprofen. Nerve stimulation-induced taurine, but not inositol, release was inhibited by 4, 4'-di-isothiocyanatostilbene-2,2'-disulphonic acid (DIDS) (50 micromol/L). Single-cell fluorescence studies with isolated liver PC, Kupffer cells (KC), sinusoidal endothelial cells (SEC), and hepatic stellate cells (HSC) revealed that phenylephrine induced an increase in cytosolic free Ca2+ only in PC and HSC, but not in KC and SEC, whereas extracellular uridine triphosphate (UTP) produced Ca2+ transients/oscillations in all liver cell types studied. Phenylephrine had no effect on osmolyte release from isolated KC and SEC, but increased taurine (but not inositol) release from PC and inositol (but not taurine) efflux from HSC. The data suggest that: 1) liver cell hydration and-consecutively-osmolyte content are modulated by hepatic nerves via an alpha-adrenergic mechanism, which does not involve eicosanoids or hemodynamic changes; 2) that PC and HSC are the primary targets for nerve-dependent alpha-adrenergic activation, whereas 3) KC and SEC probably do not express alpha-adrenoceptors coupled to Ca2+ mobilization or osmolyte efflux.