Vadim Kuznetsov. Informal Biography by Eyes of His First Adviser

The paper is dedicated to the memory of prominent theoretical physicist and mathematician Dr. Vadim Kuznetsov who worked, in particular, in the fields of the nonlinear dynamics, separation of variables, integrability theory, special functions. It includes his short research biography, an account of the start of his research career and the list of publications.Comment: This is a contribution to the Vadim Kuznetsov Memorial Issue on Integrable Systems and Related Topics, published in SIGMA (Symmetry, Integrability and Geometry: Methods and Applications) at http://www.emis.de/journals/SIGMA

On Classical r-Matrix for the Kowalevski Gyrostat on so(4)

We present the trigonometric Lax matrix and classical r-matrix for the Kowalevski gyrostat on so(4) algebra by using the auxiliary matrix algebras so(3,2) or sp(4).Comment: Published in SIGMA (Symmetry, Integrability and Geometry: Methods and Applications) at http://www.emis.de/journals/SIGMA

The most reactive amide as a transition-state mimic for cis-trans interconversion.

1-Azatricyclo[3.3.1.1(3,7)]decan-2-one (3), the parent compound of a rare class of 90°-twisted amides, has finally been synthesized, using an unprecedented transformation. These compounds are of special interest as transition-state mimics for the enzyme-catalyzed cis-trans rotamer interconversion of amides involved in peptide and protein folding and function. The stabilization of the amide group in its high energy, perpendicular conformation common to both systems is shown for the rigid tricyclic system to depend, as predicted by calculation, on its methyl group substitution pattern, making 3 by some way the most reactive known "amide".Financial assistance from Enamine Ltd. (www.enamine.net) is gratefully acknowledged. We also thank Dr. V. Stepanenko for valuable advice and encouragement which helped to find the nonstandard solutions to the synthetic problems, and Vitaliy Bilenko for drawing our attention to the instructive EI mass spectrum of compound 8.This is the final published version of the article, originally published in the Journal of the American Chemical Society, 2015, 137 (2), pp 926–93, DOI: 10.1021/ja511460

Surgical treatment of trophoblastic disease. Modern concept and contradictions (literature review)

A review of studies on the comparison of the effectiveness of surgical treatment of malignant trophoblastic tumors before the start of standard chemotherapy and in terms of combination treatment is presented. According to Russian and foreign studies, surgical treatment is relevant for patients with primary or metastatic tumor resistance. The article presents the results of treatment of patients after various types of operations. The most common volume of surgery was a hysterectomy. The article also discusses the results of treatment of benign forms of trophoblastic disease. Surgical treatment of a malignant trophoblastic tumor before the start of standard chemotherapy was performed according to vital indications or in connection with a tumor determined by imaging methods. And the analysis carried out in Blokhin National Medical Research Center of Oncology showed expected prognoses for patients who underwent surgical treatment prior to the start of standard chemotherapy regimens. Such patients were admitted to the clinic with a resistant or disseminated form of the tumor. During their treatment, high-dose chemotherapy or additional surgical interventions were required, which significantly worsened the prognosis of the disease. In the opposite case, when removing a localized resistant primary tumor or its metastasis, in the postoperative period, chemotherapy was not carried out in connection with marker remission

Nature of Fast Relaxation Processes and Spectroscopy of a Membrane-Active Peptide Modified with Fluorescent Amino Acid Exhibiting Excited State Intramolecular Proton Transfer and Efficient Stimulated Emission

A fluorescently labeled peptide that exhibited fast excited state intramolecular proton transfer (ESIPT) was synthesized, and the nature of its electronic properties was comprehensively investigated, including linear photophysical and photochemical characterization, specific relaxation processes in the excited state, and its stimulated emission ability. The steady-state absorption, fluorescence, and excitation anisotropy spectra, along with fluorescence lifetimes and emission quantum yields, were obtained in liquid media and analyzed based on density functional theory quantum-chemical calculations. The nature of ESIPT processes of the peptide’s chromophore moiety was explored using a femtosecond transient absorption pump-probe technique, revealing relatively fast ESIPT velocity (∼10 ps) in protic MeOH at room temperature. Efficient superluminescence properties of the peptide were realized upon femtosecond excitation in the main long-wavelength absorption band with a corresponding threshold of the pump pulse energy of ∼1.5 μJ. Quantum-chemical analysis of the electronic structure of the peptide was performed using the density functional theory/time-dependent density functional theory level of theory, affording good agreement with experimental data

Highly Fluorinated Peptide Probes with Enhanced In Vivo Stability for 19^{19}F‐MRI

A labeling strategy for in vivo $^{19}$F-MRI (magnetic resonance imaging) based on highly fluorinated, short hydrophilic peptide probes, is developed. As dual-purpose probes, they are functionalized further by a fluorophore and an alkyne moiety for bioconjugation. High fluorination is achieved by three perfluoro-tert-butyl groups, introduced into asparagine analogues by chemically stable amide bond linkages. d-amino acids and β-alanine in the sequences endow the peptide probes with low cytotoxicity and high serum stability. This design also yielded unstructured peptides, rendering all 27 $^{19}$F substitutions chemically equivalent, giving rise to a single $^{19}$F-NMR resonance with <10 Hz linewidth. The resulting performance in $^{19}$F-MRI is demonstrated for six different peptide probes. Using fluorescence microscopy, these probes are found to exhibit high stability and long circulation times in living zebrafish embryos. Furthermore, the probes can be conjugated to bovine serum albumin with only amoderate increase in $^{19}$F-NMR linewidth to ≈30 Hz. Overall, these peptide probes are hence suitable for in vivo $^{19}$F-MRI applications