323 research outputs found

    Far-red emitting fluorescent dyes for optical nanoscopy: Fluorinated silicon–rhodamines (SiRF dyes) and phosphorylated oxazines.

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    Far-red emitting fluorescent dyes for optical microscopy, stimulated emission depletion (STED), and ground-state depletion (GSDIM) super-resolution microscopy are presented. Fluorinated silicon–rhodamines (SiRF dyes) and phosphorylated oxazines have absorption and emission maxima at about λ≈660 and 680 nm, respectively, possess high photostability, and large fluorescence quantum yields in water. A high-yielding synthetic path to introduce three aromatic fluorine atoms and unconventional conjugation/solubilization spacers into the scaffold of a silicon–rhodamine is described. The bathochromic shift in SiRF dyes is achieved without additional fused rings or double bonds. As a result, the molecular size and molecular mass stay quite small (<600 Da). The use of the λ=800 nm STED beam instead of the commonly used one at λ=750–775 nm provides excellent imaging performance and suppresses re-excitation of SiRF and the oxazine dyes. The photophysical properties and immunofluorescence imaging performance of these new far-red emitting dyes (photobleaching, optical resolution, and switch-off behavior) are discussed in detail and compared with those of some well-established fluorophores with similar spectral properties

    Hydroxylated fluorescent dyes for live-cell labeling: Synthesis, spectra and super-resolution STED.

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    Hydroxylated rhodamines, carbopyronines, silico- and germanorhodamines with absorption maxima in the range of 530-640 nm were prepared and applied in specific labeling of living cells. The direct and high-yielding entry to germa- and silaxanthones tolerates the presence of protected heteroatoms and may be considered for the syntheses of various sila- and germafluoresceins, as well as -rhodols. Application in stimulated emission depletion (STED) fluorescence microscopy revealed a resolution of 50-75 nm in one- and two-color imaging of vimentin-HaloTag fused protein and native tubulin. The established structure-property relationships allow prediction of the spectral properties and the positions of spirolactone/zwitterion equilibria for the new analogs of rhodamines, carbo-, silico- and germanorhodamines using simple additive schemes

    THE RESULTS OF TREATMENT OF PATIENTS WITH POSTOPERATIVE VENTRAL HERNIAS

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    The article describes the experience of surgical treatment of 391 patient with postoperative ventral hernias with use of different variants of elimination of hernial defects. It is shown that the search of optimum, variant of plastic operation in each case is necessary for elimination, of hernial defects

    Parametric generation of second sound in superfluid helium: linear stability and nonlinear dynamics

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    We report the experimental studies of a parametric excitation of a second sound (SS) by a first sound (FS) in a superfluid helium in a resonance cavity. The results on several topics in this system are presented: (i) The linear properties of the instability, namely, the threshold, its temperature and geometrical dependencies, and the spectra of SS just above the onset were measured. They were found to be in a good quantitative agreement with the theory. (ii) It was shown that the mechanism of SS amplitude saturation is due to the nonlinear attenuation of SS via three wave interactions between the SS waves. Strong low frequency amplitude fluctuations of SS above the threshold were observed. The spectra of these fluctuations had a universal shape with exponentially decaying tails. Furthermore, the spectral width grew continuously with the FS amplitude. The role of three and four wave interactions are discussed with respect to the nonlinear SS behavior. The first evidence of Gaussian statistics of the wave amplitudes for the parametrically generated wave ensemble was obtained. (iii) The experiments on simultaneous pumping of the FS and independent SS waves revealed new effects. Below the instability threshold, the SS phase conjugation as a result of three-wave interactions between the FS and SS waves was observed. Above the threshold two new effects were found: a giant amplification of the SS wave intensity and strong resonance oscillations of the SS wave amplitude as a function of the FS amplitude. Qualitative explanations of these effects are suggested.Comment: 73 pages, 23 figures. to appear in Phys. Rev. B, July 1 st (2001

    Effect of acute copper sulfate exposure on olfactory responses to amino acids and pheromones in goldfish (Carassius auratus)

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    Exposure of olfactory epithelium to environmentally relevant concentrations of copper disrupts olfaction in fish. To examine the dynamics of recovery at both functional and morphological levels after acute copper exposure, unilateral exposure of goldfish olfactory epithelia to 100 μM CuSO4 (10 min) was followed by electro-olfactogram (EOG) recording and scanning electron microscopy. Sensitivity to amino acids (L-arginine and L-serine), generally considered food-related odorants, recovered most rapidly (three days), followed by that to catecholamines(3-O-methoxytyramine),bileacids(taurolithocholic acid) and the steroid pheromone, 17,20 -dihydroxy-4-pregnen- 3-one 20-sulfate, which took 28 days to reach full recovery. Sensitivity to the postovulatory pheromone prostaglandin F2R had not fully recovered even at 28 days. These changes in sensitivity were correlated with changes in the recovery of ciliated and microvillous receptor cell types. Microvillous cells appeared largely unaffected by CuSO4 treatment. Cilia in ciliated receptor neurones, however, appeared damaged one day post-treatment and were virtually absent after three days but had begun to recover after 14 days. Together, these results support the hypothesis that microvillous receptor neurones detect amino acids whereas ciliated receptor neurones were not functional and are responsible for detection of social stimuli (bile acidsandpheromones).Furthermore, differences in sensitivity to copper may be due to different transduction pathways in the different cell types

    Comparative assessment of endovideosurgical accesses in treatment of congenital hydronefrosis in children

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    Purpose. Recently published dates has confirmed that the most widespread methods of treatment primary hydronephrosis in children are endovideosurgical. But there are no significant objective criteria for choosing the optimal access: transperitoneal or retroperitoneal. We have evaluated an outcome of laparoscopic treatment hydronephrosis utilizing different access. Material and methods. Since 2008 to 2017 331 children (95 girls, 236 boys) with congenital hydronephrosis were underwent 342 endovideoscopic operations. Mean age 3.56 years (range 3m – 18 years). In 305 children was used transperitoneal access (TPA) and in 26 – retroperitoneal (RPA). We used the technique of dismembered pyeloplasty by Anderson-Hynes. Drainage was performed by an antegrade or retrograde JJ stent. Follow-up ultrasound was performed on 2 and 5 days after the operation. The ureteral stent was removed at 6-8 weeks after the operation. The continuance of hospitalization was 5-7 day. Results. 296 patients : 297 with TPA (mean age 4,8 years) and 25 with RPA(mean age 1,9 years) undergoing pyeloplasty were examined after 1-3-6-12 months. The duration of the operation with TPA was 80 ± 40 minutes, and with RPA - 110 ± 40 minutes (p <0,05). No UTI were seen. There was no difference in renal pelvis diameter (% improvement) between the two groups (TPA- 66% and 62% in RPA; p=0,6). 3 patients (1,1%) with TPA required re-intervention (2 ps -stent replacement and 1p - re-operation ), no patients with RPA required re-operation. Conclussion. Dispite of the good clinical outcome of treatment with difference accesses and statistical significance the results, the absence peritoneal injury and probability urinary extravasation make RPA in congenital hydronephrosis optimal in young children

    Effect of Lithium Borate Coating on the Electrochemical Properties of LiCoO2 Electrode for Lithium-Ion Batteries

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    Received: 13.10.2020. Revised: 18.11.2020. Accepted: 26.11.2020. Available online: 21.12.2020.This article belongs to the regular issue.The effect of a protective coating of fused lithium borate, Li3BO3, on the physicochemical and electrochemical characteristics of LiCoO2 has been studied. A cathode material produced by the SCS method using binary organic fuel, glycine and citric acid. The influence of the experiment conditions on the morphology, crystal structure and specific surface of lithium cobaltite was studied. Electrochemical testing of LiCoO2∙nLi3BO3 samples, n = 5 and 7 mass %, has been performed in the cathode Li|Li+-electrolyte|LiCoO2∙nLi3BO3 half-cell using 1M LiPF6 in EC/DMC mixture (1:1) as electrolyte in the 2.7-4.3 V range at normalized discharge current С/10, С/5, С/2. The maximal initial discharge capacity of 185 mAh/g was detected for the samples with 5 mass % Li3BO3. The coulomb efficiency of optimal materials in the 40th cycle was 99.1%.The work was performed in accordance with the state as-signments of the Institute of Chemistry of Solids of the Ural Branch of the RAS, No. AAAA-A19-119031890026-6 and No. АААА-А19-119102990044-6, the state assignment of the Institute of Problems of Chemical Physics of the RAS, No. АААА-А19-119061890019-5, and Thematic map No. 0089-2019-0007 «Functional materials for chemical power sources»
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