17 research outputs found
Тне intranatal causes of grave condition at premature newborns
In this article we present statistic analysis of delivery tactic in premature labors. The newborns of those mothers who took the tocolitical therapy and prevention of RDS were needed in artificial pulmonary ventilation accordingly in 3,3-5,0 and twice times rarer
A Dyad as Photocatalyst for Light-Driven Sulfide Oxygenation with Water As the Unique Oxygen Atom Source
International audienceWith the objective to convert light energy into chemical oxidation energy, a ruthenium-based dyad constituted of the assembly of a photosensitizer and a catalytic fragment was synthesized. Upon irradiation with blue LEDs, and in the presence of an electron acceptor, the complex is able to catalyze selective sulfide oxygenation involving an oxygen atom transfer from water to the substrate. Electrochemical and photophysical studies highlighted a proton-coupled electron transfer (PCET) to access to a high valent oxidant Ru(IV) oxo species
Long-term forest composition and its drivers in taiga forests in NW Russia
Understanding the processes behind long-term
boreal forest dynamics can provide information that assists
in predicting future boreal vegetation under changing
environmental conditions. Here, we examine Holocene
stand-scale vegetation dynamics and its drivers at the
western boundary of the Russian taiga forest in NW Russia.
Fossil pollen and conifer stomata records from four small
hollow sites and two lake sites are used to reconstruct local
vegetation dynamics during the Holocene. Variation partitioning
is used to assess the relative importance of the
potential drivers (temperature, forest fires and growing site
wetness) to the long-term stand-scale dynamics in taiga
forest. All the main tree taxa, including the boreal keystone
species Picea abies (Norway spruce) and Larix sibirica
(Siberian larch), have been locally present since 10,000 cal
yr BP. The constant Holocene presence of L. sibirica at
three small hollow sites suggests a fast postglacial immigration
of the species in northern Europe. Picea was present
but not dominant at all study sites until its expansion
between 8,000 and 7,000 cal yr BP markedly changed the
forest structure through the suppression of Betula (birch),
Pinus (pine) and Larix. Our results demonstrate that in
general, the Holocene forest dynamics in our study region
have been driven by temperature, but during short intervals
the role of local factors, especially forest fires, has been
prominent. The comparison between sites reveals the
importance of local factors in stand-scale dynamics in taiga
forests. Therefore, the future responses of taiga forest to
climate change will be predominantly modulated by the
local characteristics at the site