Влияние нейроаксиального блока на изменения гемодинамики у рожениц

The results of the multicentric study on «The safety of the spinal anesthesia during the caesarean section» describing the analysis of the hemodynamic changes due to neuroaxial block in parturients were presented. Thirteen clinics participated in the study. The volume of the sampling includes 2228 spinal anesthesia protocols. The study results confirm the consistency of some well-known regulations and standards of the safe performance of spinal anesthesia. Moreover, the following facts were revealed: the preinfusion during the spinal anesthesia does not have a preventive effect on arterial hypotension; the increase of the infusion volume results in elevating of the arterial hypotension frequency during spinal anesthesia; the bandaging of the lower extremities is a serious measure to prevent the hemodynamic complications; the application of 6% pentastarch solution for the postin-fusion is an effective method to prevent the arterial hypotension during spinal anesthesia for the cesarean section.Представлены результаты мультицентрового исследования «Безопасность спинномозговой анестезии во время операции кесарева сечения», относящиеся к изучению изменений гемодинамики у рожениц под влиянием нейроаксиального блока. В исследовании приняло участие 13 клиник. Объем изучаемой выборки составил 2228 протоколов спинномозговой анестезии. Результаты исследования подтвердили состоятельность ряда общеизвестных положений и стандартов безопасности проведения спинномозговой анестезии. Кроме того, было выявлено, что преинфузия при спинномозговой анестезии в акушерстве не оказывает профилактического действия в отношении артериальной гипотонии; увеличение объема преинфузии способствует повышению частоты случаев артериальной гипотонии во время спинномозговой анестезии; бинтование нижних конечностей является серьезной мерой профилактики гемодинамических осложнений; применение 6% раствора пентакрахмала в качестве постинфузии является эффективным методом профилактики артериальной гипотонии при спинномозговой анестезии операций кесарева сечения

Storylines: an alternative approach to representing uncertainty in physical aspects of climate change

As climate change research becomes increasingly applied, the need for actionable information is growing rapidly. A key aspect of this requirement is the representation of uncertainties. The conventional approach to representing uncertainty in physical aspects of climate change is probabilistic, based on ensembles of climate model simulations. In the face of deep uncertainties, the known limitations of this approach are becoming increasingly apparent. An alternative is thus emerging which may be called a ‘storyline’ approach. We define a storyline as a physically self-consistent unfolding of past events, or of plausible future events or pathways. No a priori probability of the storyline is assessed; emphasis is placed instead on understanding the driving factors involved, and the plausibility of those factors. We introduce a typology of four reasons for using storylines to represent uncertainty in physical aspects of climate change: (i) improving risk awareness by framing risk in an event-oriented rather than a probabilistic manner, which corresponds more directly to how people perceive and respond to risk; (ii) strengthening decision-making by allowing one to work backward from a particular vulnerability or decision point, combining climate change information with other relevant factors to address compound risk and develop appropriate stress tests; (iii) providing a physical basis for partitioning uncertainty, thereby allowing the use of more credible regional models in a conditioned manner and (iv) exploring the boundaries of plausibility, thereby guarding against false precision and surprise. Storylines also offer a powerful way of linking physical with human aspects of climate change

Studying the Shielding of an Electromagnetic Field by a Textile Material Containing Ferromagnetic Nanostructures

The technology has been proposed for manufacturing a textile material that contains ferromagnetic nanoparticles for shielding electromagnetic fields. It has been shown that the most effective method of sticking together between nano-particles and the fibers of the textile material is the application of magnetic liquid with nanoparticles on the material and its exposure in a heterogeneous permanent magnetic field. Under the condition of a magnetic field intensity of 450 A/m and the exposure to it for 12 hours, the implantation of the nanoparticles into the linen fabric becomes almost irreversible. The protective properties of the developed material have been investigated. When impregnated with a magnetic liquid in the amount of 45–50 g/m2 (a ferromagnetic particle content of 9 % by weight), the material's shielding coefficients for 1–3 layers amount to: for the electric field of industrial frequency 1.4÷4.8; for a magnetic field, 1.9÷8.1. Following the magnetic treatment, these indicators are 2.9÷8.6 and 2.3÷8.9, respectively. In order to remove technological components such as vacuum oil and oleic acid from the magnetic fluid, it would suffice to apply a synthetic detergent, which has been confirmed by experimentally.We have investigated the efficiency of the obtained result under actual industrial conditions. It was established that the decrease in the magnetic field intensity of industrial frequency and its inter-harmonics by a single layer of the impregnated material without magnetic treatment is 1.4, with a magnetic treatment ‒ 2. In this case, there is no significant decrease in the level of the natural geomagnetic field. We have modeled the distribution of a magnetic field in the human body for the case of manufacturing a protective suit from the developed material. Under the conditions of a warranted reduction in the magnetic field intensity by 2 times in critical places, an increase in the field level is observed in the cervical region due to the increase in the magnetic resistance in this region. This should be considered when designing the protective suit configuratio

Abrupt Schottky Junctions in Al/Ge Nanowire Heterostructures

International audienceIn this Letter we report on the exploration of axial metal/semiconductor (Al/Ge) nanowire heterostructures with abrupt interfaces. The formation process is enabled by a thermal induced exchange reaction between the vapor-liquid-solid grown Ge nanowire and Al contact pads due to the substantially different diffusion behavior of Ge in Al and vice versa. Temperature-dependent I-V measurements revealed the metallic properties of the crystalline Al nanowire segments with a maximum current carrying capacity of about 0.8 MA/cm(2). Transmission electron microscopy (TEM) characterization has confirmed both the composition and crystalline nature of the pure Al nanowire segments. A very sharp interface between the (111) oriented Ge nanowire and the reacted Al part was observed with a Schottky barrier height of 361 meV. To demonstrate the potential of this approach, a monolithic Al/Ge/Al heterostructure Was used to fabricate a novel impact ionization device