Hot Fingers: Individually Addressable Graphene-Heater Actuated Liquid Crystal Grippers.

Liquid crystal-based actuators are receiving increased attention for their applications in wearables and biomedical or surgical devices, with selective actuation of individual parts/fingers still being in its infancy. This work presents the design and realization of two gripper devices with four individually addressable liquid-crystal network (LCN) actuators thermally driven via printed graphene-based heating elements. The resistive heat causes the all-organic actuator to bend due to anisotropic volume expansions of the splay-aligned sample. A heat transfer model that includes all relevant interfaces is presented and verified via thermal imaging, which provides good estimates of dimensions, power production, and resistance required to reach the desired temperature for actuation while maintaining safe electrical potentials. The LCN films displace up to 11 mm with a bending force of 1.10 mN upon application of 0-15 V potentials. The robustness of the LCN finger is confirmed by repetitive on/off switching for 500 cycles. Actuators are assembled into two prototypes able to grip and lift objects of small weights (70-100 mg) and perform complex actions by individually controlling one of the device's fingers to grip an additional object. Selective actuation of parts in soft robotic devices will enable more complex motions and actions to be performed.

[Peculiarities of CI processor fitting in children with auditory neuropathy spectrum disorders]. / Osobennosti nastroiki protsessora kokhlearnogo implantata u detei so slukhovoi (auditornoi) neiropatiei.

The peculiarities of cochlear implant (CI) processor fitting in children with auditory neuropathy spectrum disorders (ANSD) were investigated. At the 1-st fitting of the CI processor a standard protocol of parameters was used in all patients, including patients with cochlear nerve hypoplasia. After the initial fitting session, the behavioral tonal thresholds with CI in 55% of patients were 30-35 dB, in 32.% of patients - 40-50 dB. After 3-6 months, 65% of children with ANSD showed significant progress in auditory-speech development, which made it possible to use the standard protocol of tuning parameters for them with the most comfortable and threshold levels of electrical stimulation adjusted according to the child's reactions. The best dynamics was observed in 2 children with presynaptic ANSD with a confirmed DFNB9 (OTOF) gene mutation. In 35% of children, there was no progress in distinguishing speech signals and instability of reactions to sounds persisted after 6 months using of CI and speech therapy training, despite the low tonal thresholds of hearing. In these children the coding strategy was changed, the stimulation frequency was reduced, and the pulse width was increased. This helped to improve the discrimination of sounds with CI and progress in the child's speech development. The results demonstrate that children with ANSD require more frequent correction of CI processor settings: 1st year - every 3 months, then at least 2 times a year until the optimal coding strategy and settings are achieved. To predict the effectiveness of CI and determine the optimal tactics for setting up the CI processor in patients with ANSD, the preoperative examination should include MRI of the cerebellopontine angle to detect anomalies of the cochlear nerve and genetic examination to identify mutations that cause hearing impairment in patients with ANSD.

Depletion of COPI in cancer cells: the role of reactive oxygen species in the induction of lipid accumulation, noncanonical lipophagy and apoptosis.

The coatomer protein complex 1 (COPI) is a multisubunit complex that coats intracellular vesicles and is involved in intracellular protein trafficking. Recently we and others found that depletion of COPI complex subunits zeta (COPZ1) and delta (ARCN1) preferentially kills tumor cells relative to normal cells. Here we delineate the specific cellular effects and sequence of events of COPI complex depletion in tumor cells. We find that this depletion leads to the inhibition of mitochondrial oxidative phosphorylation and the elevation of reactive oxygen species (ROS) production, followed by accumulation of lipid droplets (LDs) and autophagy-associated proteins LC3-II and SQSTM1/p62 and, finally, apoptosis of the tumor cells. Inactivation of ROS in COPI-depleted cells with the mitochondrial-specific quencher, mitoquinone mesylate, attenuated apoptosis and markedly decreased both the size and the number of LDs. COPI depletion caused ROS-dependent accumulation of LC3-II and SQSTM1 which colocalizes with LDs. Lack of double-membrane autophagosomes and insensitivity to Atg5 deletion suggested an accumulation of a microlipophagy complex on the surface of LDs induced by depletion of the COPI complex. Our findings suggest a sequence of cellular events triggered by COPI depletion, starting with inhibition of oxidative phosphorylation, followed by ROS activation and accumulation of LDs and apoptosis.

Contactless Control of Local Surface Buckling in Photoaligned Gold/Liquid Crystal Polymer Bilayers.

Wrinkling is a powerful technique for the preparation of surface structures over large areas, but it is difficult to simultaneously control the direction, period, and amplitude of the wrinkles without resorting to complicated procedures. In this work, we demonstrate a wrinkling system consisting of a liquid crystal polymer network and a thin layer of gold, in which the direction of the wrinkles is controlled by the alignment of the liquid crystal molecules and the average amplitude and period are controlled by a high-intensity UV irradiation. The UV exposure represses the amplitude and period dictated by the total exposure. Using photoalignment and photomasks, we demonstrate an unprecedented control over the wrinkling parameters and were able to generate some striking optical patterns. The mechanism of the wrinkle suppression was investigated and appears to involve localized photodegradation at the polymer-gold interface, possibly due to the formation of mechanoradicals.

[A role of neuroprotective therapy in the rehabilitation of children with sensorineural hearing loss, IV degrees, after cochlear implanta-tion]. / Rol' neiroprotektivnoi terapii v abilitatsii detei s sensonevral'noi tugoukhost'yu IV stepeni posle provedeniya kokhlearnoi implantatsii.

OBJECTIVE: To study clinical/psychological characteristics in children with sensorineural hearing loss, IV degrees, before and after the cochlear implantation (CI) and to assess the dynamics of speech development during the rehabilitation using the neuroprotective drug cerebrolysin. MATERIAL AND METHODS: Authors examined 93 patients, aged from 5 to 8 years. The main group (n=46) received cerebrolysin, the control group was not treated with this drug. A diagnostic study included patient's history, neurological and neuropsychological examinations, auditory perception and sound reproduction. RESULTS AND CONCLUSION: According to the Meaningful Use of Speech Scale, 23% of children of the main group demonstrated the best results due to the better speech communication strategies. No significant between-group differences were found in the level of auditory perception 6 months after CI. The level of articulation was higher in the main group. Cognitive functioning was improved in children treated with cerebrolysin.

[Steroidal compounds from the Pacific starfish Mithrodia clavigera and their toxic properties against human melanoma cells].

The new sulfated polyhydroxysteroid has been isolated from the Pacific starfish Mithrodia clavigera, collected from Maldives Islands and named as mitrotriol (I, Na-salt of (20S)-3beta,6alpha,20-trihydroxy-5alpha-cholest-9(11)-ene 3-O-sulfate). In addition six previously known compounds, including glycosides: echinasteroside B, granulatoside A, linckoside K, forbeside L and thornasterol sulfate A and cholesterol sulfate were isolated and identified. The structure of mitrotriol was elucidated by spectroscopic methods (mainly 2D NMR: 1H, 13C, DEPT, COSY-45, NOESY, HSQC and HMBC) and mass-spectrometry. For selected compounds, concentrations that showed cytotoxic activity against melanoma cells SK-MEL-28, SK-MEL-5 and RPMI-7951 were determined.

[Polar steroids from Solaster endeca starfish and the physiological activity of polar steroids from three starfish species].

Four polyhydroxylated steroids, new (20R)-5alpha-cholestan-3beta,6alpha,8,15alpha,24,26-hexaol (I) and known (20R,25S)-5alpha-cholestan-3beta6alpha,8,15beta,16beta,26-hexaol, (20R,25S)-5alpha-cholestan-3beta,6alpha,15beta,16beta,26-pentaol, and marthasterone sulfate were isolated from the Solaster endeca starfish inhabiting the Sea of Okhotsk and characterized. Steroid (I) contains a 24,26-dihydroxylated side chain, which is uncommon for starfish polyols. The isolated steroids and related metabolites from two starfish species of the Evasterias genus (in total, 15 compounds) were weakly cytotoxic in a human HeLa cell culture and some of them were inhibitors of nonspecific esterase from mouse Ehrlich carcinoma. The effects of these compounds on the p53 protein activity were studied in a yeast two-hybrid test system and both inhibitors and stimulators of this activity were found among them.

[Steroid compounds from two pacific starfish of the genus Evasterias].

Three new steroid glycosides (evasteriosides C, D, and E), along with six known compounds, were isolated from two Pacific starfish of the genus Evasterias. Evasterioside C from E. retifera collected from the Sea of Japan was identified as (20R,22E)-3-O-(beta-D-xylopyranosyl)-24-nor-5alpha-cholest-22-ene-3beta,6beta,8,15alpha,26-pentaol 26-sulfate sodium salt. The structures of evasterioside D and E from E. echinosoma (collected from the Gulf of Shelichov, the Sea of Okhotsk) were established as (20R,24S)-24-O-(beta-D-glucopyranosyl)-5alpha-cholestane-3beta,6alpha,8,15beta,24-pentaol and (20R,24S)-3,24-di-O-(beta-D-xylopyranosyl)-cholest-4-ene-3beta,6beta,8,15alpha,24-pentaol, respectively. In addition, the known compounds pycnopodiosides A and C, luridoside A, 5alpha-cholestane-3beta,6alpha,8,15beta,16beta,26-hexaol, 5alpha-cholestane-3beta,6alpha,8,15beta,24-pentaol 24-sulfate sodium salt, and marthasterone sulfate sodium salt were identified in E. echinosoma. The structures of the isolated compounds were established on the basis of spectroscopic analyses using 1D and 2D NMR techniques, mass spectrometry, and some chemical transformations.

[Genetic variability and differentiation in the larch populations within the range of Larix olgensis A. Henry in Primor'e region].

The level of within- and among-population variation of larch inhabiting the range of Larix olgensis A. Henry in Primorye was estimated on the basis of 440 RAPD loci identified by means of 12 random primers. In ten population examined, the proportion of polymorphic loci was 35-60%, the average expected heterozygosity varied from 0.1340 to 2169, and the average gene flow estimate was 1.38. According to Fisher's test for heterogeneity, the pairwise differences of the fragment frequencies between the populations were statistically significant. The subdivision index G(ST) = 0.2663 indicated that the interpopulation variation component accounted for approximately 27% of the total variation. Coefficients of Nei's genetic distance between the populations varied from 0.0137 to 0.0934. Most of the samples with high support clustered according to the geographic positions relative to one another within the range. These results suggest that the populations examined are characterized by high genetic variation, like the larch populations of Siberia and the Russian Far East studied earlier, but, in contrast to the latter, exhibit higher among-population variability.

[Trofosides A and B and other cytostatic steroid-derived compounds from the Far East starfish Trofodiscus über].

Three new polar steroids identified as trofoside A, (20R,24S)-24-O-(3-O-methyl-beta-D-xylopyranosyl)-3beta,6alpha,8,15beta,24-pentahydroxy-5alpha-cholestane, its 22(23)-dehydro derivative (trofoside B), and 15-sulfoxy-(20R,24S)-5alpha-cholestane-3beta,6beta,8,15alpha,24-pentaol sodium salt, were isolated from Trofodiscus uber starfish extracts collected in the Sea of Okhotsk. Two known compounds, trofoside A aglycone, (20R,24S)-3beta,6alpha,8,15beta,24-pentahydroxy-5alpha-cholestane, and triseramide, (20R,24R,25S,22E)-24-methyl-3beta,6alpha,8,15beta-tetrahydroxy-5alpha-cholest-22-en-27-oic acid (2-sulfoethyl)amide sodium salt, were also found. The structures of the isolated polyoxysteroids were established from their spectra. Minimal concentrations causing degradation of unfertilized egg-cells of the sea-urchin Strongylocentrotus intermedius (C(min)) and terminating the cell division at the stage of the first division (C(min) embr.), as well as the concentrations causing 50% immobilization of sperm cells (ImC50) and inhibiting their ability to fertilize egg-cells by 50% (IC50) were determined for the isolated compounds. Of three compounds highly toxic in embryos and sea-urchin sperm cells, the polyol with a sulfo group in the steroid core was the most active; two glycosides with monosaccharide chains located at C3 and C24 atoms were less toxic. Note that all the compounds with the spermiotoxic activities differently affected the embryo development. The positions of monosaccharide residues in the core considerably influence the compound activity. For example, both mono- and double chained glycosides with the monosaccharide fragment at C3 and C24 atoms are active against sea-urchin sperm cells and embryos, whereas the C24 glycosylated trofoside A does not affect embryos and displays a poor spermiotoxicity.

[Steroid compounds from the Far East starfish Pteraster obscurus and the ophiura Asteronyx loveni].

Seven sulfated polyhydroxysteroids were isolated from the Far East starfish Pteraster obscurus and the ophiura (snake star) Asteronyx loveni (collected in the Sea of Okhotsk) and characterized: disodium and sodium salts of (20R)-24-methyl-2beta-hydroxycholesta-5,24(28)-diene-3alpha,21-diyl disulfate, (20R)-5alpha-cholestane-3beta,21-diyl disulfate, (20R)-3beta-hydroxy-5alpha-cholestan-21-yl sulfate, (20R)-cholest-5-ene-3beta,21-diyl disulfate, (20R)-2beta-hydroxycholest-5-ene-3alpha,21-diyl disulfate, (20R)-cholest-5-en-3beta-yl sulfate, and (20R)-5alpha-cholestan-3beta-yl sulfate. The first four compounds turned out to be new, whereas the others were identical to the known compounds. Structures of the isolated steroids were identified by two-dimensional NMR spectroscopy and other physicochemical methods. The compounds isolated from starfish are structurally similar to typical ophiuroid metabolites, which support the opinion of some taxonomists that starfish and ophiuroids are phylogenetically related classes.

[New steroid glycosides from the starfish Fromia milleporella].

Two new steroid glycosides from the starfish Fromia milleporella collected in the Seychelles were isolated and characterized: milleporoside A, (20R, 24R)-29-O-[3-O-methyl-beta-D-xylopyranosyl-(1-->4)-3-O-methyl-beta-D-xylopyranosyl]-24-ethyl-5alpha-cholestane-3beta,4beta,6alpha,8,15beta,16beta,29-heptaol, and milleporoside B, (20R, 24R)-(22E)-28-O-[3-O-methyl-beta-D-xylopyranosyl-(1-->4)-3-O-methyl-beta-D-xylopyranosyl]-24-methyl-5alpha-cholest-22-ene-3beta,4beta,6alpha,8,15beta,16beta,28-heptaol. The structures of the glycosides were determined from their spectra and a comparison with spectral characteristics of known compounds. These compounds exhibit a moderate cytostatic activity toward the embryos of the sea urchin Strongylocentrotus intermedius.

[Steroid compounds from far Eastern starfishes Henricia aspera and H. tumida].

Six new natural compounds were isolated from two Far Eastern starfish species, Henricia aspera and H. tumida, collected in the Sea of Okhotsk. Two new glycosylated steroid polyols were obtained from H. aspera: asperoside A and asperoside B, which were shown to be (20R,24R,25S)-3-O-(2,3-di-O-methyl-beta-D-xylopyranosyl)-24-methyl-5alpha-cholest-4-ene-3beta,6beta,8,15a,16beta,26-hexaol and (20R,24R,25S,22E)-3-O-(2,4-di-O-methyl-beta-D-xylopyranosyl)-24-methyl-5alpha-cholest-22-ene-3beta,4beta,6beta,8,15alpha,26-hexaol, respectively. Two other glycosylated polyols, tumidoside A, with the structure elucidated as (20R,22E)-3-O-(2,4-di-O-methyl-beta-D-xylopyranosyl)-26,27-di-nor-24-methyl-5alpha-cholest-22-ene-3beta,4beta,6beta,8,15alpha,25-hexaol, and tumidoside B, whose structure was elucidated as (20R,24S)-3-O-(2,3-di-O-methyl-beta-D-xylopyranosyl)-5alpha-cholestan-3beta,4beta,6beta,8,15alpha,24-hexaol, were isolated from the two starfish species. (20R,24S)-Salpha-Cholestan-3beta,6beta,15alpha,24-tetraol and (20R,24S)-5alpha-cholestan-3beta,6beta,8,15alpha,24-pentaol were identified only in H. tumida. The known monoglycosides henricioside H1 and laeviuscolosides H and G were also identified in both species.

[Genetic variability and interrelationship of Siberian and Far Eastern larches from RAPD-analysis data]. / Geneticheskaia izmenchivost' i vzaimootnosheniia listvennits Sibiri i dal'nego vostoka po dannym RAPD-analiza.

Genetic diversity of larches from six geographically isolated regions, Tomsk, Irkutsk, Ulan-Ude (Siberia), and Blagoveshchensk, Khabarovsk, Yuzhno-Sakhalinsk (Far East) was examined by means of RAPD analysis. Tree DNA samples were compared using 457 RAPD loci (97% of which were polymorphic), identified with 17 primers of random sequences. In the samples examined, 32 to 49% of the genes were in heterozygous state, mean expected heterozygosity (Hexp) varied from 0.1373 to 0.1891, and the genetic distances (DN) for different sample pairs varied from 0.0361 to 0.1802. The main population parameters were determined for Larix sibirica Ledeb., L. gmelinni (Rupr.) Rupr., and L. kamtschatica (Rupr.) Carr. Analysis of the genetic relationships showed that L. kamtschatica was characterized by highest genetic differentiation from the other larches examined, while larches from Primorskii krai were genetically close to L. sibirica.

[Morphologic changes due to hyperthermia (experimental study)]. / Morfologicheskie izmeneniia pri peregrevanii (éksperimental'noe issledovanie).

Acute and chronic overheating appeared to induce similar shock reaction in all organs, with systemic disorders of microcirculation. The organs demonstrated irreversible hemodynamic disturbances with secondary hypoxic injury. Structural disorders in organs result in their functional deficiency and subsequent pathologic conditions.

[Steroidal polyols from Far Eastern starfish Henricia sanguinolenta and H. leviuscula leviuscula]. / Steroidnye polioly iz dal'nevostochnykh morskikh zvezd Henricia sanguinolenta i H. leviuscula leviuscula.

Two new asterosaponins, (20R)-3-O-beta-D-(2-O-methylxylopyranosyl)-24-propylcholest-4-ene-3 beta,6 beta, 8, 15 alpha, 16 beta, 29-hexaol (sanguinoside A) and (20R,24S)-3-O-beta-D-(2,3,4-tri-O-methylxylopyranosyl)-5 alpha-cholestane-3 beta, 4 beta, 6 beta, 8, 15 alpha, 24-hexaol (sanguinoside B), were isolated from two species of Pacific Far Eastern Starfish Henricia sanguinolenta and H. leviuscula leviuscula, collected in the Sea of Okhotsk. Both glycosides contain aglycones with pentahy-droxysteroid nuclei of similar structures, which are substituted at the 3-hydroxy group with differently methylated beta-D-xylosyl residues. Sanguinoside A has an unusual structure of its aglycone side chain, whereas sanguinoside B has a unique permethylated carbohydrate chain. In addition, laevisculoside G, a known glycoside, was identified in the H. leviuscula starfish. The structures of the isolated glycosides were established by interpreting their spectral data and by comparing their spectral characteristics with those of known compounds. The English version of the paper. Russian Journal of Bioorganic Chemistry, 2004, vol. 30, no. 2; see also http://www.maik.ru.

[Steroid compounds from the Far Eastern starfish Diplopteraster multipes]. / Steroidnye soedineniia iz dal'nevostochnoi morskoi zvezdy Diplopteraster multipes.

Sodium salt of (20R)-3 alpha,4 beta-dihydroxycholest-5-ene-21-yl sulfate and disodium salts of (20R)-4 beta-hydoxycholest-5-ene-3 alpha,21-diyl disulfate, (20R)-24-methylcholest-5,24(28)-diene-3 alpha,21-diyl disulfate, (20R)-24-methyl-5 alpha-cholest-24(28)-ene-3 alpha,21-diyl disulfate, (20R)-cholest-5-ene-3 alpha, 21-diyl disulfate, (20R)-5 alpha-cholestane-3 alpha,21-diyl disulfate, and (20R)-3 alpha-hydroxycholest-5-ene-2 beta,21-diyl disulfate were isolated from the far eastern starfish Diplopteraster multipes and characterized. These compounds differ structurally from sulfated polyhydroxysteroids in other starfish species. At the same time, they are typical secondary metabolites of Ophiuroidea and have some structural features characteristic of the ophiuroid-isolated steroids, namely the 3 alpha-hydroxy (or 3 alpha-sulfoxy) and 21-sulfoxy groups. These data support the opinion of some taxonomists that starfishes and ophiuroids are phylogeneteically related classes and are closer to each other than to other classes of the Echinodermata phylum.

Cytoskeletal control of fibroblast length: experiments with linear strips of substrate.

In order to understand the factors determining the length of fibroblasts, three cell lines (mouse embryonic fibroblasts plus human fibroblast lines AGO 1523 and M19) were cultivated on the usual planar substrate (glass) and on specially prepared narrow linear strips of the same substrate, where the cells could spread only linearly. Morphometric measurements showed that the average length of cells of each type on the 'unidimensional' strips was no different from that on the usual 'bidimensional' substrate. The addition of colcemid significantly decreased cell length on both substrates, whereas cytochalasin D increased the length. We concluded that fibroblasts have an intracellular mechanism maintaining a relatively constant average cell length. This mechanism may involve the dynamic balance of centripetal and centrifugal forces developed by two cytoskeletal systems: the microtubules and the actin-myosin cortex. Three epitheliocyte cell lines (rat IAR2, canine MDCK and bovine FBT) were tested but, in contrast to fibroblasts, they did not maintain similar cell lengths on the usual substrate and on the linear strips, suggesting that control of length is cell-type-specific.