Hole-transporting interlayers based on pyrazine-containing conjugated polymers for perovskite solar cells.

Hybrid organic-inorganic perovskite solar cells (PSCs) have drawn great attention in the past decade due to the rapid growth of their power conversion efficiency (PCE) and the advantage of their low-cost fabrication. The hole-transport materials (HTMs) play a crucial role in achieving high efficiency and operational stability of PSCs. In this work, we report the synthesis of two novel conjugated polymers by coupling of the alkylsilyl-substituted benzo[1,2-b:4,5-b']dithiophene unit with the thiophene-bridged pyrazine block and their investigation as dopant-free HTMs in n-i-p PSCs. The devices with polymer PBPyT-ex (poly[(4,8-bis(5-(triisopropylsilyl)thiophen-2-yl)-2,6-benzo[1,2-b:4,5-b']dithiophene)-alt-5,5'-(2,5-bis(4-(2-ethylhexyl)thiophen-2-yl)pyrazine)]) demonstrate PCEs up to 17.5%, outperforming the 14.9% efficiency of PSCs with PBPyT-in (poly[(4,8-bis(5-(triisopropylsilyl)thiophen-2-yl)-2,6-benzo[1,2-b:4,5-b']dithiophene)-alt-5,5'-(2,5-bis(3-(2-ethylhexyl)thiophen-2-yl)pyrazine)]), which is attributed to the difference in the quality of HTM films. The results obtained feature the combination of pyrazine, thiophene and benzodithiophene units as a successful example of polymeric HTM backbone design for PSCs with encouraging efficiency and high operational stability over 1500 h under continuous illumination.

[Preclinical study of safety of the new pharmacological substance AV0012 to treat hepatitis C].

Pharmacological safety of a new type of HCV inhibitor, AV0012, was studied including acute, subchronic and chronic toxicity in mice, rats and monkeys. Genotoxicity was assessed using the Ames test and the chromosomal aberrations assay in the bone marrow cells of mice. It is established that AV0012 has low toxicity in SHK line mice, Wistar line rats, and monkey of Rhesus macaques species. Results obtained in the study of genetic toxicity showed that AV0012 exhibits no mutagenic activity. Data on general toxicity and mutagenicity discussed in this paper, together with data on 1 the pharmacological activity, pharmacokinetics, and metabolism published previously, allow us to consider AV0012 as a candidate drug for clinical research phase I.

Integration of thermal and osmotic afferent signals in the preoptic/anterior hypothalamic neurons.

Our in vivo experiments were aimed at studying afferent links of the preoptic/anterior hypothalamus system, which integrates thermal and osmotic homeostasis. Special attention was paid to using stimulation intensities within the normal physiological range. The experiments were carried out on adult cats anesthetized with ketamine (25mg/kg) and inhalation of nitrous oxide (75 vol.%). Short-term shifts in the osmotic pressure within the cerebral vasculature were induced by infusions of 200-500 microl 3.0% or 0.2% NaCl solutions into the homolateral a. carotis (hyper- and hypoosmotic stimulations, respectively). Thermal stimulation was provided by local heating or cooling of the contralateral forelimb pad skin (+/-7.0 degrees C range). Reactions of preoptic/anterior hypothalamus neurons were classified into four types: monophasic activation, monophasic inhibition, and biphasic responses including excitation followed by inhibition or primary inhibition followed by activation. Monophasic activation was a very common occurrence among preoptic/anterior hypothalamus neuronal reactions. The responsiveness of thermosensitive preoptic/anterior hypothalamus neurons to hyperosmotic stimulation turned to be noticeably higher than that to hypoosmotic stimulation. Practically equal proportions of warm- and cold-sensitive neurons demonstrated changes in the firing activity resulting from intracarotid infusions of 3.0% NaCl solution. Infusions of 0.2% NaCl solution induced firing rate modifications in 26% (12/46) of warm-sensitive and in 32% (18/39) of cold-sensitive neurons. Cold-sensitive neurons displayed a higher sensitivity to a short-term osmotic pressure elevation in the cerebral vasculature (63%, 33/52) than warm-sensitive neurons did (43%, 22/52, P<0.05). In our study, a maximum similarity in the response types was observed when hyperosmotic infusion and skin cooling were applied, while a maximum disagreement was found when hyperosmotic stimulations were combined with skin heating. There is no doubt that preoptic/anterior hypothalamus neurons play a crucial role in the maintenance of body temperature. Several studies have also shown that osmoregulation can be affected by shifts in peripheral and hypthalmic temperatures. Information on the neurol mechanisms of interactions between the thermo- and osmoregulatory circuits in the hypothalamus remains limited. We discuss the obtained data considering the "set-point theory" of thermal hameostasis maintenance.

[The characteristics of the background neuronal activity of the rostral hypothalamus and an analysis of its alteration under the influence of the stimulation of phylogenetically heterogeneous sections of the cerebral cortex]. / Kharakterystyka fonovoï aktyvnosti neironiv rostral'noho hipotalamusa ta analiz ïï zminy pid vplyvom podraznen' filohenetychno heterohennykh viddiliv kory holovnoho mozku.

In acute experiments on cats under mixed narcosis (ketamine + N2O) we have investigated background firing activity of the rostral hypothalamic neurons and analyzed it modifications due to serial stimulation (100 imp/s, during 5 s) of the prefrontal, cingulate, pyriform cortices and hippocampus. Analysis of the ongoing mean frequency histograms allowed to single out three types of background firing activity with different rhythmical properties. Three types of interspike intervals distribution i.e. asymmetrical (A), symmetrical (S) and polymodal (P) have been distinguished as well. Cortical stimulation was found to transform types of interspike intervals distribution in 15% of hypothalamic neurons. S-type changed into P-type and A-type--into P-type. Author discussed correlation between the character of background firing activity, types of interspike intervals distribution and functional properties of hypothalamic neurons.

[Sanitary protection zones in major gas chemical enterprises]. / K voprosu o sanitarno-zashchitnykh zonakh dlia krupnykh gazokhimicheskikh kompleksov.

Results of clinical and hygienic research in the area neighboring to Orenbourg and Astrakhan gas chemical enterprises proved that sanitary protection zones planned during construction of the enterprises are inadequate. The results helped to base individual zones of sanitary protection for Orenbourg and Astrakhan gas enterprises, to form clinical and hygienic recommendations for practical management.

Influences from different areas of the cerebral cortex on preoptic neurons: morphological and electrophysiological data.

Spatial organization of neurons in the prefrontal and cingulate cortex, cortex of the piriform lobe and the hippocampus which project axons to the preoptic region, has been studied in cats using horseradish peroxidase tracing. Cortical areas were selected taking into consideration their phylogenetical distinctions. The prefrontal cortex was found to send a major portion of fibres to the preoptic region, while the density of units forming such connections was maximal in the cingulate cortex. Field potentials and neuronal reactions of the medial and lateral divisions of the preoptic region and the adjacent hypothalamic zones were studied in ketamine-anaesthetized cats. The most pronounced field potentials were recorded in the preoptic region upon stimulation of the cortex of the piriform lobe and cingulate cortex. There was a close correlation between the responses of single neurons and components of the field potentials. The majority of neurons responding to cortical stimuli were located mainly in the lateral preoptic region, where the larger amount of primary excitatory reactions were recorded. The medial preoptic region contained a smaller number of responsive neurons prevailingly generating the primary inhibitory reactions. For the lateral preoptic region the inhibition/excitation ratio was 0.6:1 at all cortical stimulations, but for the medial region it was 5.8:1. In the preoptic division adjoining the bed nucleus of the stria terminalis, the primary inhibitory reactions considerably prevailed over the primary excitatory; on the other hand, in the supraoptic nucleus the primary excitatory reactions prevailed weakly (ratios of 4.9:1 and 0.7:1, respectively). The preoptic region was found to be a zone of wide convergence of cortical inputs to single cells, where three-quarters of neurons responded to the stimulation of two, three or even four cortical areas.

[An assessment of the manifestation of the functional connections between brain structures]. / Otsenka vyrazhennosti funktsional'nykh sviazei mezhdu strukturami golovnogo mozga.

Responses of hypothalamic neurons to single (1/s, 20 impulses) stimulation of the prefrontal (area 8), cingulum (area 24), periamygdaloideus (RPA) cortex and hippocampus (field CA3) were studied on experimental cats anesthetized with ketamine. The routine elaborated for IBM PC/AT 386 provided: 1) selection of such neurone reaction with the latent period variation less than its length per the set value (5-20%); 2) selection of repeated neurone reactions with the same variability of latent periods from 20 cortical stimuli; 3) ranging of neurone reactions according to these indices. Quantitative estimation of the priority ranges made it possible to determine the profundity of the functional relations between the cerebral structures.

[Electrophysiological analysis of corticofugal influences on neurons of the preoptic area]. / Elektrofiziologicheskii analiz kortikofugal'nykh vliianii na neirony preopticheskoi oblasti.

Evoked potentials (EPs) and neuronal responses of the medial (MPO) and lateral (LPO) preoptic region (RPO) and adjacent areas of the hypothalamus to stimulation of the prefrontal (area 8), cingulum (area 24), periamigdaloideus (RPA) cortex and hippocampus (area CA3) have been studied on cats anesthetized with ketamine. Cortical areas were selected according to their evolutionary status. It is determined that the most pronounced EPs are generated in the RPO to stimulation of the periamigdaloideus and cingulum cortex. A close correlation between responses of single units and EPs waveforms is shown. The majority of neurons responsible for cortical stimuli are located mainly in the basal part of the LPO. It is this area of the RPO where the prevalence of initial excitatory reactions is observed. The MPO contains much less neurons responding to cortical stimulation. In this area of the RPO mainly initial inhibitory reactions are registered. For the LPO a ratio between the inhibitory and excitatory reactions is 0.6:1, for the MPO the same ratio is 5.8:1. In the area of the RPO adjoining the bed nucleus stria terminalis (BST) the initial inhibitory reactions prevail over the initial excitatory ones too (ratio 4.9:1). In the area of the RPO immediately adjoining the nucleus supraopticus the initial excitatory reactions are registered and the ratio between the initial inhibitory reactions and initial excitatory ones is 0.7:1. In the RPO a pronounced convergence of the stimuli from the different cortical areas to the definite cells is found as well. In the RPO which is a zone of wide convergence 3/4 of neurons responded to stimulation of two and more cortical inputs. The combinations of inputs from the prefrontal and cingulum cortex as well as from prefrontal and periamigdaloideus cortex are the most frequent types of convergence of different cortical stimuli to the preoptic neurons.