Twenty-four-hour heart preservation using continuous cold perfusion and copper (II) complexes

Spinocerebellar ataxia 7 (SCA7) is a neurodegenerative disorder characterized by degeneration of the cerebellum, brainstem and retina. The gene responsible for SCA7, located on chromosome 3p, recently was cloned and shown to contain a CAG repeat in the coding region of the gene, that is expanded in SCA7 patients of French origin. We examined the SCA7 repeat region in four Swedish SCA7 families as well as in 57 healthy controls. All Swedish SCA7 patients exhibited expanded CAG repeats with a strong negative correlation between repeat size and age of onset. The repeat length in SCA7 patients ranged from 40 to >200 repeats. The largest expansion was observed in a juvenile case with an age of onset of 3 months, and represents the longest polyglutamine stretch ever reported. In patients with 59 repeats or more, visual impairment was the most common initial symptom observed, while ataxia predominates in patients with <59 repeats. Two of the Swedish SCA7 families analysed in this study were shown to be related genealogically. The other two SCA7 families could not be traced back to a common ancestor. All four families shared the same allele on the disease chromosome at a locus closely linked to SCA7, suggesting the possibility of a founder effect in the Swedish population.     

Comparison of PVT and NaI(Tl) scintillators for vehicle portal monitor applications

The demand for radiation portal monitor (RPM) systems has increased, and their capabilities are being further scrutinized as they are being applied to the task of detecting nuclear weapons, special nuclear material, and radiation dispersal device materials that could appear at borders. The requirements and constraints on RPM systems deployed at high-volume border crossings are significantly different from those at weapons facilities or steel recycling plants, where RPMs have been historically employed. In this new homeland security application, RPM systems must rapidly detect localized sources of radiation with a very high detection probability and low false-alarm rate, while screening all of the traffic without impeding the flow of commerce. In light of this new Department of Homeland Security application, the capabilities of two popular gamma-ray-detector materials as applied to these needs are re-examined. Both experimental data and computer simulations, together with practical deployment experience, are used to assess currently available polyvinyltoluene and NaI(Tl) gamma-ray detectors for border applications.     

The Control of Colour by Using Measurement and Feedback

Colour simulation on CAD computer screens is a potentially important aid to rapid response in product development. Control of screen colour in high-resolution CRT monitors can be achieved on the basis of the principles of additive colour-mixing. The use of trichromatic-unit colour specifications is extended to include RGB drive values and provide a measured feedback signal for correcting colour. Measurement and feedback control are shown to be sucessful and are employed in the Shademaster CAD system for colour-range development.     

Identification of aroma‐active compounds in fresh and stored ‘Mor’ mandarins

In this study, gas chromatography–olfactometry (GC‐O) (sniffing) combined with gas chromatography–mass spectrometry (GC‐MS) analysis was applied to identify volatile aroma‐active compounds in homogenised segments of fresh and stored ‘Mor’ mandarins. The GC‐O nasal impact frequency method was used to identify Twenty‐three aroma‐active compounds, of which seventeen odorants were identified by GC‐MS. The aroma of fresh ‘Mor’ mandarins derived from a mixture of eleven odorants that contribute ‘green’ [(E)‐3‐hexenol and hexanal], ‘fresh’ [(E)‐carveol], ‘fruity’ (ethyl 2‐methylbutanoate), ‘citrus’ (limonene), ‘floral’ (linalool), ‘musty’ (β‐myrecene and γ‐terpinene), ‘potato’ (α‐terpinene), ‘mushroom’ (unknown 2) and ‘cabbage’ (α‐cubebene) odours. During postharvest, storage losses were observed in ‘green’ [(E)‐3‐hexenol] and ‘fresh’ [(E)‐carveol] odours, accompanied by increases in ‘fruity’ (ethyl propanoate) and several unpleasant aromas, such as ‘alcohol’ (ethanol), ‘musty’ [α‐pinene, (E)‐2‐nonenal and 1‐terpinen‐4‐ol] and ‘fatty’ (octyl acetate and δ‐cadinene) odours, all of which possibly account for the observed decrease in sensory acceptability after harvest.     

Malpractice claims against family physicians are the best doctors sued more?

There is strong evidence to show that diabetes is associated with increased oxidative stress. However, the source of this oxidative stress remains unclear. Using transgenic mice that overexpress aldose reductase (AR) in their lenses, we found that the flux of glucose through the polyol pathway is the major cause of hyperglycemic oxidative stress in this tissue. The substantial decrease in the level of reduced glutathione (GSH) with concomitant rise in the level of lipid peroxidation product malondialdehyde (MDA) in the lens of transgenic mice, but not in the nontransgenic mice, suggests that glucose autoxidation and nonenzymatic glycation do not contribute significantly to oxidative stress in diabetic lenses. AR reduction of glucose to sorbitol probably contributes to oxidative stress by depleting its cofactor NADPH, which is also required for the regeneration of GSH. Sorbitol dehydrogenase, the second enzyme in the polyol pathway that converts sorbitol to fructose, also contributes to oxidative stress, most likely because depletion of its cofactor NAD+ leads to more glucose being channeled through the polyol pathway. Despite a more than 100% increase of MDA, oxidative stress plays only a minor role in the development of cataract in this acute diabetic cataract model. However, chronic oxidative stress generated by the polyol pathway is likely to be an important contributing factor in the slow-developing diabetic cataract as well as in the development of other diabetic complications.--Lee, A. Y. W., Chung, S. S. M. Contributions of polyol pathway to oxidative stress in diabetic cataract. FASEB J. 13, 23-30 (1999)     

Dynamics of artificial satellite orbits with tesseral resonances including the effects of luni- solar perturbations

Eccentric and inclined resonant orbits exhibit complex motions that have the potential to become chaotic. Furthermore, these complex motions may also destabilize classical control strategies. Understanding the mechanisms that cause such motions to occur is critical. Previous research has determined that the interaction between resonant tesseral harmonics can produce chaotic responses in the semi-major axis and stroboscope mean node (primary variables of interest for groundtrack control) of an orbit. However, the previous work did not include the effects of potentially significant luni-solar perturbations; the present effort does so. Utilizing a variety of analytical and numerical techniques from nonlinear Hamiltonian systems theory, resonance overlap is found between interacting lunar harmonics. This overlap result can produce significant excur- sions in eccentricity. Furthermore, the potential for diffusion between the eccentricity (or inclination) and semi-major axis exists because of the coupling introduced by the tesseral harmonics. However, it is found that the interaction between these two modes (motion in eccentricity and motion in semi-major axis) is slight for orbits with periods of 12 hours or lower. It is concluded that the qualitative motion of the semi-major axis and the node, on time-scales of interest for mission planning, evolves primarily from tesseral harmonic effects. Also presented is an investigation of the local chaotic behavior near the separatrix of the primary tesseral term as inclination decreases from the critical value. Using techniques similar in form to Melnikov methods, a sufficient condition for the width of the local chaotic layer is obtained, and is compared to numerical simulations.