Experimental and Computational NMR Studies of Large Alkaloids Exemplified With Vindoline Trimer: Advantages and Limitations.

The complete H and C NMR assignments of a trimeric vindoline together with its individual components, dimeric vindolicine and monomeric vindoline, are performed based on a thorough analysis of the ROESY, COSY, HSQC, and HMBC spectra in combination with the state-of-the-art quantum-chemical calculations. A spatial structure of vindoline trimer is determined by means of computational conformational analysis in combination with the probability distribution map of its basic conformers. On the example of monoterpene indole alkaloid, the trimer vindoline, the present study reveals the power of modern computational NMR to perform identification and stereochemical studies of large natural compounds with some limitations, which may arise in the quantum chemical computing workflow.

Photo- and X-ray Induced Cytotoxicity of CeF-YF-TbF Nanoparticle-Polyvinylpyrrolidone-"Radachlorin" Composites for Combined Photodynamic Therapy.

The CeYTbF nanoparticles with a CeF hexagonal structure were synthesized using the co-precipitation technique. The average nanoparticle diameter was 14 ± 1 nm. The luminescence decay curves of the CeYTbF nanoparticles (λ = 541 nm, D-F transition of Tb) conjugated with Radachlorin using polyvinylpyrrolidone coating as well as without Radachlorin were detected.

Evaluation of the effectiveness and safety of photodynamic therapy in the treatment of precancerous diseases of the cervix (neoplasia) associated with the human papillomavirus: A systematic review.

This study provides an overview of the effectiveness and safety of PDT for the treatment of HPV-associated precancerous cervical conditions and contains recent findings from relevant research studies. A comprehensive literature search of MEDLINE/PubMed, Cochrane Central Library, and Google Scholar was conducted, including analytic epidemiological studies, and 11 papers were included. The narrative synthesis approach was used to summarize the results of the included studies.

Star algorithm for neural network ensembling.

Neural network ensembling is a common and robust way to increase model efficiency. In this paper, we propose a new neural network ensemble algorithm based on Audibert's empirical star algorithm. We provide optimal theoretical minimax bound on the excess squared risk.

6aH-Benzo[α]fluorene: NMR evidence of the unexpected product of the reaction of butyryl chloride with 1,2-diphenylacetylene.

The reaction of butyryl chloride with ethynylbenzene in the presence of AlCl afforded a mixture of the Z/E-isomers of 1-chloro-2-phenylhex-1-en-3-one. 1,2-Diphenylethyne under these conditions gave a novel polycarbocycle core, 6aH-benzo[a]fluorene. The chemical structure of 11-chloro-5,6-diphenyl-6a-propyl-6aH-benzo[a]fluorene was established by means of IE-MS, H, C NMR, COSY, HSQC, HMBC, and 2D INADEQUATE technique.

Synthesis of 5-(trifluoroacetyl)imidazoles from Bromoenones and Benzimidamides Aza-Michael Initiated Ring Closure Reaction.

Introduction: A simple method for the preparation of 5-(trifluoroacetyl)imidazoles was elaborated.

Methods: The reaction of trifluoromethyl(α-bromoalkenyl)ketones with benzimidamides was employed to afford the target heterocycles in good yields.

Results: The assembly of imidazole core proceeds aza-Michael adduct formation followed by intramolecular nucleophilic substitution and spontaneous aromatization as an oxidation sequence.

Selenium Dihalides Click Chemistry: Highly Efficient Stereoselective Addition to Alkynes and Evaluation of Glutathione Peroxidase-Like Activity of Bis(-2-halovinyl) Selenides.

Highly efficient stereoselective syntheses of novel bis(-2-chlorovinyl) selenides and bis(-2-bromovinyl) selenides in quantitative yields by reactions of selenium dichloride and dibromide with alkynes were developed. The reactions proceeded at room temperature as -addition giving products exclusively with ()-stereochemistry. The glutathione peroxidase-like activity of the obtained products was estimated and compounds with high activity were found.

Pathogenesis, Diagnosis, and Treatment of Hemostatic Disorders in COVID-19 Patients.

The novel coronavirus infection named COVID-19 was first detected in Wuhan, China, in December 2019, and it has been responsible for significant morbidity and mortality in scores of countries. At the time this article was being written, the number of infected and deceased patients continued to grow worldwide. Most patients with severe forms of the disease suffer from pneumonia and pulmonary insufficiency; in many cases, the disease is generalized and causes multiple organ failures and a dysfunction of physiological systems.

A Regioselective Synthesis of Novel Functionalized Organochalcogen Compounds by Chalcogenocyclofunctionalization Reactions Based on Chalcogen Halides and Natural Products.

The regioselective synthesis of novel functionalized condensed organochalcogen compounds by chalcogenocyclofunctionalization reactions based on chalcogen halides and the natural products thymol and carvacrol has been developed. The reactions of selenium dibromide with allyl thymol and allyl carvacrol proceeded in methylene chloride at room temperature in the presence of NaHCO affording bis[(7-isopropyl-4-methyl-2,3-dihydro-1-benzofuran-2-yl)methyl] and bis[(4-isopropyl-7-methyl-2,3-dihydro-1-benzofuran-2-yl)methyl] selenides in 90-92% yield. Similar sulfides were obtained in 70-72% yields by the reaction of sulfur dichloride in chloroform under reflux.

New technique of dissection of internal mammary vessels for breast reconstruction.

Background: Although internal mammary vessels are considered the best recipients for free flap breast reconstruction, they present the notable drawback of limited accessibility. The aim of this study was to develop a minimally invasive surgical technique for the dissection of internal mammary vessels as recipients for breast reconstruction.

Methods: From 2008 to 2018, we performed 32 unilateral microsurgical breast reconstructions (mean patient age: 40.

Natural Compounds and Their Structural Analogs in Regio- and Stereoselective Synthesis of New Families of Water-Soluble 2,3-[1,3]thia- and -Selenazolo[3,2-]pyridin-4-ium Heterocycles by Annulation Reactions.

It has been found that both eugenol and isoeugenol derivatives reacted with 2-pyridinesulfenyl and 2-pyridineselenenyl halides in a regioselective mode affording products with opposite regiochemistry. Synthesis of new families of 2,3-[1,3]thia- and -selenazolo[3,2-]pyridin-4-ium heterocycles has been developed by annulation reactions of 2-pyridinechalcogenyl halides with natural compounds (eugenol, isoeugenol, methyl eugenol, methyl isoeugenol, acetyl eugenol, trans-anethole) and their structural analogs. The influence of the substrate structure and the nature of halogen on the product yields are studied.

HLA class I alterations in breast carcinoma are associated with a high frequency of the loss of heterozygosity at chromosomes 6 and 15.

HLA class I (HLA-I) molecules play a crucial role in the presentation of tumor antigenic peptides to CD8+ T cells. Tumor HLA-I loss provides a route of immune escape from T cell-mediated killing. We analyzed HLA-I expression in 98 cryopreserved breast cancer tissues using a broad panel of anti-HLA-I antibodies.

Adenovirus expressing β2-microglobulin recovers HLA class I expression and antitumor immunity by increasing T-cell recognition.

Optimal tumor cell surface expression of human leukocyte antigen (HLA) class I molecules is essential for the presentation of tumor-associated peptides to T-lymphocytes. However, a hallmark of many types of tumor is the loss or downregulation of HLA class I expression associated with ineffective tumor antigen presentation to T cells. Frequently, HLA loss can be caused by structural alterations in genes coding for HLA class I complex, including the light chain of the complex, β2-microglobulin (β2m).

[Central lymphodissection in carcinoma of the thyroid gland].

Experience with central lymphodissection (CLD) was analyzed in 93 patients with primary thyroid cancer (pT1-4aN0-1a). Prophylactic central lymphodissection was fulfilled in 48 patients, therapeutic CLD in 45 patients. The size and spread of the primary thyroid tumor had no difference in both groups of patients.

Efficient recovery of HLA class I expression in human tumor cells after beta2-microglobulin gene transfer using adenoviral vector: implications for cancer immunotherapy.

Here we report a successful use of a non-replicating adenovirus expressing the wild-type human beta2m gene in recovery of normal human leucocyte antigen (HLA) class I expression in beta2m-null cancer cells. Total loss of HLA class I expression in these cell lines is caused by a mutation in beta2m gene and a loss of heterozygosity in chromosome 15 carrying another copy of that gene. Normal HLA class I expression on the tumour cell surface is critical for the successful outcome of cancer immunotherapy as T cells can only recognize tumour-derived peptides in a complex with self-HLA class I molecules.

[Sorption and contact-activating properties of the <> anastomosis zone: effect of suture material (communication II)].

The authors have carried out a comparative analysis of the interaction between two types of suture material with blood components, as well as studied the effect of heparin-mediated modification on the sorption and contact-activating processes in the zone of the anastomosis. The blood-compatible properties of the latter was assesses in vitro. It was determined that by minute 120 of the contact with blood, the largest amount of protein is had been absorbed by the anastomoses performed using the Prolene thread - 112 microg/cm2.

[Transformation of bioprosthesis-artery anastomotic area after blood exposure: the effect of suture material].

Vascular graft implantation is accompanied with tissue reaction which is determined partially by the nature of suture material. In experiments in vitro edges of arterial diepoxid-preserved bioprostheses were sutured with Prolene filament, nickelide-titanium wire (TiNi) or absorbable polydioxanone monofilament (PDS). Morphological changes in anastomotic area after blood exposure were assessed with scanning electronic microscope.

[Prevalence and molecular-genetic typing of nonsyndromal neurosensory deafness in the Chuvash Republic].

Summarized genetic epidemiological characteristics of nonsyndromic sensorineural deafness in six raions of Chuvash Republic (Cheboksary, Kanash, Morgaushi, Tsivil'sk, Mariinski Posad, and Alatyr') are presented. A total of 264,419 individuals were examined. Forty-five families (60 affected individuals) with autosomal recessive (AR) and 8 families (18 affected individuals) with autosomal dominant (AD) nonsyndromic sensorineural deafness (NSSD) were identified.

[Population genetic study of the Alatyr region of the Republic of Chuvashiia].

Population genetic characteristics were estimated in the Alatyr' raion (administrative district) of the Republic of Chuvashia, which has long been populated by three ethnic groups. The ethnic assortativeness values in the town of Alatyr' and the rural area of the district were 1.17 and 1.

[Comparison of Chuvashs with Maris and Russians by vital statistics and the Crow index].

Genetic demographic characteristics were calculated for Chuvash and Russian inhabitants of the Republic of Chuvashia. The generation lengths were 27.09 and 26.

[Genetic epidemiological study of populations in three regions of Chuvashia Republic].

Comprehensive population genetic and medical genetic studies were performed in three raions (districts) of Chuvashia. The population of these districts is more than 90% Chuvash. About 70% of the families that completed reproduction had two or three children.

[Sensitivity of biological objects to the effects of the geomagnetic field].

It is shown on the basis of calculations of energy sublevels of the hyperfine structure that the effect of the geomagnetic field upon the impurity atoms in the volume of living cells should be considered in relation to the value of geomagnetic field induction pulses delta B. When delta B > or = 10 pT and the dielectric constant epsilon > or = 10, magnetodipole transitions between sublevels of the hyperfine structure within one term are possible in impurity atoms in their 2P-state. During magnetic storms with delta B > or = 100 nT magnetodipole or magnetoquadrupole forced transitions from 2P1/2 and 2P3/2 states to 2S1/2 metastable state are possible in the resonant zones formed by intersection of hyperfine energy sublevels of the corresponding excited levels.