Identification and Properties of New Flavins in Electron-Transferring Flavoprotein from Peptostreptococcus elsdenii and Pig-Liver Glycolate Oxidase

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65168/1/j.1432-1033.1974.tb03515.x.pd

One life ends, another begins: Management of a brain-dead pregnant mother - A systematic review -

Background: An accident or a catastrophic disease may occasionally lead to brain death (BD) during pregnancy. Management of brain-dead pregnant patients needs to follow special strategies to support the mother in a way that she can deliver a viable and healthy child and, whenever possible, also be an organ donor. This review discusses the management of brain-dead mothers and gives an overview of recommendations concerning the organ supporting therapy. Methods: To obtain information on brain-dead pregnant women, we performed a systematic review of Medline, EMBASE and the Cochrane Central Register of Controlled Trials (CENTRAL). The collected data included the age of the mother, the cause of brain death, maternal medical complications, gestational age at BD, duration of extended life support, gestational age at delivery, indication of delivery, neonatal outcome, organ donation of the mothers and patient and graft outcome. Results: In our search of the literature, we found 30 cases reported between1982 and 2010. A nontraumatic brain injury was the cause of BD in 26 of 30 mothers. The maternal mean age at the time of BD was 26.5 years. The mean gestational age at the time of BD and the mean gestational age at delivery were 22 and 29.5 weeks, respectively. Twelve viable infants were born and survived the neonatal period. Conclusion: The management of a brain-dead pregnant woman requires a multidisciplinary team which should follow available standards, guidelines and recommendations both for a nontraumatic therapy of the fetus and for an organ-preserving treatment of the potential donor

The role of water in the conductivity of vanadium pentoxide xerogel films

The measurement of DC conductivity of thin films deposited from vanadium pentoxide gels between 200 and 600 K in air, oxygen and a vacuum of 5 x 10 -7 torr has revealed that reversible changes in conductivity are determined by hydration/dehydration phenomena. The removal of weakly bonded water results in a conductivity decrease from ≃ 2 S/m to ≃ 0.3 S/m at room temperature. Heat treatment between 430 and 550 K in oxygen leads to the maximally dehydrated phase in which σ ≃ 9 × 10-3 S/m at 300 K. The essentially unchanged activation energies in all of the phases suggest that hydration affects the charge carrier concentration only.Nous avons mesuré entre 200 et 600 K la conductivité à l'air libre ou sous un vide de 5 x 10-7 torr, de couches minces obtenues à partir de gels de pentoxydes de vanadium. Ces mesures ont montré que les changements réversibles de la conductivité sont liés à des phénomènes d'hydratation et de déshydratation. Le départ de l'eau faiblement absorbée entraîne, à température ambiante, une diminution de la conductivité de ≃ 2 S/m à 0,3 S/m. Un traitement thermique entre 430 et 550 K dans une atmosphère d'oxygène conduit à une phase de déshydratation maximum avec σ ≃ 9 x 10-3 S/m à 300 K. Le fait que les énergies d'activation sont similaires dans les différentes phases suggère que le processus d'hydratation entraîne seulement une modification de la concentration des porteurs de charge

Use of chromatographic models for computerized optimization of coupling-point pressure in dual-column gas chromatography

A novel computer-assisted procedure is presented for optimization of the coupling-point pressure (pm) of a column for the gas chromatographic separation of multi-component samples on two capillary columns of fixed dimensions and stationary phase polarities operated at constant temperature with constant inlet (pi) and outlet (po) pressures. The retention of all solutes in the system is monitored by the chromatographic model ks,i = ka,i + xb (kb,i - ka,i) where k is the capacity factor obtained on the polar column (A), the non-polar column (B) and on the columns coupled in series (S) and xB is the weight factor determined from column characteristics and carrier gas pressures (pi, pm and po). The optimization procedure is monitored by a dependence of the optimization criterion (Cp) against the column coupling-point pressure (pm): Cp = f(pm) for both column series AB and BA. The optimization criterion is based on a number of peaks resolved equal to or better than the required resolution factor (primary part) in the shortest analysis time (secondary part). Comparison of the novel optimization procedure with those based on window diagrams shows that the new model is superior as it gives unambiguously the maximum number of peaks that can be resolved under the given conditions equal to or better than the required resolution in the shortest analysis time

AMORPHOUS VANADIUM OXIDES BY CVD : PREPARATION, ELECTRICAL AND MAGNETIC PROPERTIES

Chemical vapour deposition of VOCl3 with H2O in controlled atmosphere is a unique method in producing amorphous vanadium oxides that contain only V5+ and V4+ ions with continuously varying valence ratio /c/ between <0.02 and ≈ 1.0. The room temperature d.c. conductivity of as prepared V2O5 films ranges between 10-5 and 10-3 ohm-1m-1 and is strongly dependent on preparation conditions. Increasing the valence ratio the conductivity first increases to ≈ 10-2 ohm-lm-1, then declines to 10-4 ohm-lm-1. EPR spectra indicate that the environment of V4+ ions is not identical in films of different compositions