A New Series of Cobalt and Iron Clathrochelates with Perfluorinated Ribbed Substituents

The study tackles one of the challenges in developing platinum-free molecular electrocatalysts for hydrogen evolution, which is to seek for new possibilities to ensure large turnover numbers by stabilizing electrocatalytic intermediates. These species are often much more reactive than the initial electrocatalysts, and if not properly stabilized by a suitable choice of functionalizing substituents, they have a limited long-time activity. Here, we describe new iron and cobalt(II) cage complexes (clathrochelates) that in contrast to many previously reported complexes of this type do not act as electrocatalysts for hydrogen evolution. We argue that the most probable reason for this behavior is an excessive stabilization of the metal(I) species by perfluoroaryl ribbed groups, resulting in an unprecedented long-term stability of the metal(I) complexes even in acidic solutions.

Dynamics of the crystal structure of tin-based type-I clathrates with different degrees of disorder in their cationic frameworks

The temperature dependencies of heat capacity, C_P(T), and cubic unit cell parameter, a(T), were experimentally obtained in the range of 2-300 K for the compounds Sn₂₄P_19.2I₈, Sn₂₀Zn₄P_20.8I₈, and Sn₁₇Zn₇P₂₂I₈, which belong to a family of type-I clathrates. The experimental data were analyzed in the frames of the Debye-Einstein approximation, further accounting for the contributions of positional disorder in the clathrate frameworks as well as those of defect modes arising from the distribution of guest atoms over unequal in energy but close in space positions inside the framework cages. By fitting the experimental data, the Debye and Einstein characteristic temperatures describing the dynamics of the framework and guest atoms, respectively, were obtained. Their analysis revealed peculiar dependencies of the characteristic temperatures upon the number of substituted zinc atoms and the concentration of vacancies in the framework, which are discussed in this paper.

[Cancer-testis genes in colon cancer]

The expression of cancer-testis (CT) genes varies with tumor type. There are tumors with high, low, and intermediate gene expressions. Tumor cells of different origin are characterized by ST gene co-expression. The expression of ST genes increases in later stages of tumor development in the presence of metastases. In colon cancer, the tumor samples showed most frequently MAGE-A and SSX mRNA. The peripheral blood samples displayed most commonly XAGE, MAGE-C, and SSX mRNA. In patients with colon cancer, the expression of TSP50, MAGE-A(1-6), and SSX1,2,4 genes was associated with a poor prognosis, that of MAGE-C1 and XAGE1 was related to a favorable prognosis.

Structural irregularities and peculiarities of low-temperature thermal properties of Sn24P19.4Br8 clathrate

Temperature changes of the heat capacity and unit cell parameters of Sn₂₄P_19.4Br₈ clathrate were experimentally determined in the temperature range of 2 to 300 K. The data obtained were analyzed using Debye-Einstein approximation and taking into account the impact of both disorder in the host matrix and the presence of vacancies in the framework. Anomalous negative contribution to the thermal expansion was revealed and related to the defect mode influence on the clathrate thermal properties as a result of vibrations of two-level systems (TLS). The guest atoms that have the opportunity to occupy spatially close yet energetically non-equivalent positions in the asymmetric environment of the host matrix atoms play a principal role in the TLS formation. The results are compared with those previously obtained for semiclathrate Ge₃₁P₁₅Se₈.

Unpredictable cycloisomerization of 1,11-dien-6-ynes by a common cobalt catalyst

1,11-Dien-6-ynes undergo cycloisomerization in the presence of the cobalt catalytic system CoBr₂/phosphine ligand/Zn/ZnI₂ giving cyclohexene, diene or cyclopropane structures depending on the type of the phosphine ligand. This unpredictable behaviour suggests that, although the availability of the cobalt catalytic system is appealing, the development of well-defined catalysts is desirable for further progress.

[Clinical features of exogenous organic mental disorders in patients with HIV infection]

AIM

To specify clinical/dynamic features of organic mental disorders in patients with HIV and to characterize the formation and course of psychoorganic syndrome.

MATERIAL AND METHODS

The study included 250 HIV-infected patients with mental disorders and 50 injection drug users (166 men and 84 women, mean age 30.6±6.3 years). Clinical, psychological methods and laboratory instrumental examinations were performed.

RESULTS AND CONCLUSION

Course of the infection process and premorbid personality play an important role in the development of exogenous organic mental disorders in patients with HIV infection.

[The correlation of expression of MUC1, ICAM1, IL32, FcyR3A and FoxP3 in tumor niduses of patients with breast cancer]

The hypo-glycated mucin I (MUC I) frequently is redundantly expressed in cells of breast carcinoma that is considered as an unfavorable prognostic marker for patients with breast cancer. The purpose of study is to evaluate in tumor areas of patients with breast cancer the interrelationships between expression of MUC I and genes participating in implementation of immune reactions. The technique of polymerase chain reaction with reverse transcription in real-time was applied to investigate expression of genes of MUC I, Fas, ICAMI, FcyR3A, FcyR3B, FoxP3, IL2Ra, IL32 and TNF in tumor areas of 40 patients with breast cancer. The level of mRNA of each of analyzed genes was evaluated relatively to three genes of household. The rate of detection of mRNA MUC I amounted to 80%, mRNA Fas - 95%, mRNA ICAM I - 97.5%, mRNA FcyR3A - 95%, mRNA FcyR3B - 32.5%, mRNA FoxP3 - 85%, mRNA IL2Ra - 87.5%, mRNA IL32 - 75%, mRNA TNF - 95%. The direct correlation was established between levels of mRNA MUC I, ICAM I, IL32, FcyR3A and FoxP3. The most strong relationship was registered between levels of expression of genes MUC I and IL32 (r-0.72; p=0.0001). In comparison with MUC I negative breast carcinoma, MUC I positive breast carcinoma characterized by higher level of mRNA of pro-inflammatory cytokines IL32 and ЕТА, molecules of adhesion ICAM I and molecular marker of T-regulative cells FoxP3. The given profile of expression of genes in tumors of patients with breast cancer demonstrates relationship of expression of MUC I with inflammation and its modulation by T-regulative cells. The effect of expression of analyzed genes on phenotype of cancer cells and course of disease are discussed.

Synthesis, X-ray structure and electrochemical properties of hybrid binuclear metallophthalocyaninate-capped tris-pyridineoximates

New antimony-capped iron and nickel(ii) tris-pyridineoximates easily underwent transmetallation with zirconium and hafnium(iv) phthalocyaninates giving metallophthalocyaninato-cross-linked complexes.

Preparation, X-ray Structures, Spectroscopic, and Redox Properties of Di- and Trinuclear Iron-Zirconium and Iron-Hafnium Porphyrinoclathrochelates

The first hybrid di- and trinuclear iron(II)-zirconium(IV) and iron(II)-hafnium(IV) macrobicyclic complexes with one or two apical 5,10,15,20-tetraphenylporphyrin fragments were obtained using transmetalation reaction between n-butylboron-triethylantimony-capped or bis(triethylantimony)-capped iron(II) clathrochelate precursors and dichlorozirconium(IV)- or dichlorohafnium(IV)-5,10,15,20-tetraphenylporphyrins under mild conditions. New di- and trinuclear porphyrinoclathrochelates of general formula FeNx₃((Bn-Bu)(MTPP)) and FeNx₃(MTPP)₂ [M = Zr, Hf; TPP = 5,10,15,20-tetraporphyrinato(2-); Nx = nioximo(2-)] were characterized by one-dimensional (¹H and ¹³C{¹H}) and two-dimensional (COSY and HSQC) NMR, high-resolution electrospray ionization mass spectrometry, UV-visible, and magnetic circular dichroism spectra, single-crystal X-ray diffraction experiments, as well as elemental analyses. Redox properties of all complexes were probed using electrochemical and spectroelectrochemical approaches. Electrochemical and spectroelectrochemical data suggestive of a very weak, if any, long-range electronic coupling between two porphyrin π-systems in FeNx₃(MTPP)₂ complexes. Density functional theory and time-dependent density functional theory calculations were used to correlate spectroscopic signatures and redox properties of new compounds with their electronic structures.

Anomalies in thermal expansion and heat capacity of TmB50 at low temperatures: magnetic phase transition and crystal electric field effect

We experimentally study the heat capacity and thermal expansion of thulium boride (TmB₅₀) at temperatures of 2-300 K. The wide temperature range (2-180 K) of boride negative expansion was revealed. We found the anomalies in C(T) heat capacity temperature dependence, attributed to the Schottky contribution (i.e. the influence of the crystal electric field: CEF), as well as the magnetic phase transition. CEF-splitting of the f-levels of the Tm³⁺ ion was described by the Schottky function of heat capacity with a quasi-quartet in the ground state. Excited multiplets are separated from the ground state by energy gaps δ₁ = 100 K, and δ₂ ≈ 350 K. The heat capacity maximum at T_max ≈ 2.4 K may be attributed to the possible magnetic transition in TmB₅₀. Other possible causes of the low-temperature maximum of C(T) dependence are the nonspherical surroundings of rare earth atoms due to the boron atoms in the crystal lattice of the boride and the emergence of two-level systems, as well as the splitting of the ground multiplet due to local magnetic fields of the neighboring ions of thulium. Anomalies in heat capacity are mapped with the thermal expansion features of boride. It is found that the TmB₅₀ thermal expansion characteristic features are due to the influence of the CEF, as well as the asymmetry of the spatial arrangement of boron atoms around the rare earth atoms in the crystal lattice of RB₅₀. The Grüneisen parameters, corresponding to the excitation of different multiplets of CEF-splitting, were determined. A satisfactory accordance between the experimental and estimated temperature dependencies of the boride thermal expansion coefficient was achieved.

Polymorphism in a Cobalt-Based Single-Ion Magnet Tuning Its Barrier to Magnetization Relaxation

A large barrier to magnetization reversal, a signature of a good single-molecule magnet (SMM), strongly depends on the structural environment of a paramagnetic metal ion. In a crystalline state, where SMM properties are usually measured, this environment is influenced by crystal packing, which may be different for the same chemical compound, as in polymorphs. Here we show that polymorphism can dramatically change the magnetic behavior of an SMM even with a very rigid coordination geometry. For a cobalt(II) clathrochelate, it results in an increase of the effective barrier from 109 to 180 cm^-1, the latter value being the largest one reported to date for cobalt-based SMMs. Our finding thus highlights the importance of identifying possible polymorphic phases in search of new, even more efficient SMMs.

Surgical management of neurologically complicated kyphoscoliosis using transposition of the spinal cord: Case report

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Case of patient with single-stage correction of severe congenital kyphoscoliotic spinal deformities is provided.

•

Combined anterior-posterior approach was applied.

•

Transposition of the spinal cord followed by correction using vertebral instrumentation made it possible to improve trunk balance and stop deformity progression.

Background

Transposition of the spinal cord made it possible to achieve mobilization of the fixed kyphoscoliosis, significantly increase spinal canal volume and improve spinal canal shape. This helped to eliminate spinal cord compression and achieve complete regression of the existing neurological symptoms.

Methods and results

We report the clinical case of surgical management of neurologically complicated kyphoscoliotic deformity of the thoracic spine by transposition of the spinal cord and correction using posterior segmental spinal instrumentation.

Conclusions

The required correction of severe kyphoscoliosis was performed; the risks of trunk imbalance, deformity progression, and instrumentation failure in the long-term postoperative period were reduced.

Level of evidence

Level IV – 1 case.

[Nebulized budesonide in the treatment of exacerbations of chronic obstructive pulmonary disease: Efficacy, safety, and effects on the serum levels of soluble differentiation molecules]

AIM

To investigate the efficacy and safety of nebulized budesonide and systemic glucocorticosteroids (GCS) (SGCS) in the treatment of an exacerbation of chronic obstructive pulmonary disease (COPD) and their effects on the serum concentration of soluble leukocyte differentiation antigens.

MATERIALS AND METHODS

Seventy-eight hospitalized patients with an acute exacerbation of COPD were randomized into two groups: 1) 37 patients took nebulized budesonide 4 mg/day; 2) 41 patients received intravenous prednisolone. The symptoms of COPD, forced expiratory volume in one second (FEV1) and other spirometric indicators, peripheral blood oxygen saturation (SpO2), and adverse events were studied. The serum levels of the soluble adhesion molecules CD50 (sCD50) and CD54 (sCD54) and the lymphocyte activation molecules CD38 (sCD38) and CD25 (sCD25) were investigated by an enzyme immunoassay.

RESULTS

There was a significant resolution of the symptoms of COPD, FEV1, and SpO2 in both groups after treatment. The incidence of hyperglycemia episodes was lower in the budesonide group than in the sGCS group. GCSs caused a decrease in the serum level of soluble interleukin-2 receptor (sCD25) in both groups. A prednisolone cycle, unlike a budesonide one, was found to reduce the concentrations of sCD54, sCD50, and sCD38.

CONCLUSION

Nebulized budesonide is an effective and safe alternative to SGCS in treating an exacerbation of COPD. Inhaled GCSs, unlike SGCSs, exhibit anti-inflammatory activity, but exert no immunosuppressive activity.

Genetic Instability in Locus rs5498 E469K (A/G) of ICAM-1 Gene in Patients with Colorectal Cancer and Breast Cancer

Single-nucleotide polymorphism rs5498 E469K (A/G) in ICAM-1 gene modulates functional activity of this protein and is associated with the risk of some diseases. Tumor cell rs5498 E469K (A/G) genotypes were compared with genotypes of patients with colorectal and breast cancer, residents of the Nizhniy Novgorod region. Specimens of peripheral blood and tumor foci from patients with colorectal and breast cancer and peripheral blood specimens from normal subjects were analyzed. The frequency of genotypes of single-nucleotide rs5498 E469K (A/G) sequence in the Nizhny Novgorod population coincide with the frequency of genotypes characteristic of residents of Germany. Comparison of genotypes of peripheral blood and tumor cells from patients with colorectal and breast cancer showed loss of cancer cell heterozygosity. The frequency of heterozygosity loss increases with colorectal cancer progress from one stage to another.

Crosslinking of Chitosan with Dialdehyde Derivatives of Nucleosides and Nucleotides. Mechanism and Comparison with Glutaraldehyde

In medical and pharmaceutical applications, chitosan is used as a component of hydrogels-macromolecular networks swollen in water. Chemical hydrogels are formed by covalent links between the crosslinking reagents and amino functionalities of chitosan. To date, the most commonly used chitosan crosslinkers are dialdehydes, such as glutaraldehyde (GA). We have developed novel GA like crosslinkers with additional functional groups-dialdehyde derivatives of uridine (oUrd) and nucleotides (oUMP and oAMP)-leading to chitosan-based biomaterials with new properties. The process of chitosan crosslinking was investigated in details and compared to crosslinking with GA. The rates of crosslinking with oUMP, oAMP, and GA were essentially the same, though much higher than in the case of oUrd. The remarkable difference in the crosslinking properties of nucleoside and nucleotide dialdehydes can be clearly attributed to the presence of the phosphate group in nucleotides that participates in the gelation process through ionic interactions with the amino groups of chitosan. Using NMR spectroscopy, we have not observed the formation of aldimine bonds. It can be concluded that the real number of crosslinks needed to cause gelation of chitosan chains may be less than 1%.

The synthesis of sterically hindered amines by a direct reductive amination of ketones

An atom-economical methodology for the synthesis of sterically hindered tertiary amines was developed, which is based on a complementary Rh- and Ru-catalyzed direct reductive amination of ketones with primary and secondary amines using carbon monoxide as a deoxygenating agent.

[Role of MUC1 Expression in Tumor Progression]

Mucin 1 (MUC1) is a multistructural and multifunctional protein that is involved in regulating diverse cellular activities. This strongly glycosylated transmembrane protein forms a mucous gel on the surface of epithelial cells that protects the cells from injury. MUC1 acts as a signaling molecule and transcription factor modulating metabolism and resistance to bacterial-induced inflammation. This article presents a review of the relationship between structural and functional changes of the MUC1 and the characteristics of cancer cells. The alteration in MUC1 expression level, a number of structural forms, protein glycosylation and localization occurs in cancer cells. These alterations lead to metabolic reprogramming associated with proliferation, resistance to hypoxia and angiogenesis which affects the survival of cancer cells. Furthermore, cancer cells can take advantage of MUC1 interaction with adhesion molecules for invasion and metastasis. Thus, MUC1 plays a key role both in the homeostasis of epithelial cells and in cancer progression. Understanding the role of MUC1 expression in tumor cells survival is important for the development of new monitoring and therapeutic approaches for the treatment MUC1 positive maligancies.

Negative thermal expansion and anomalies of heat capacity of LuB50 at low temperatures

Heat capacity and thermal expansion of LuB50 boride were experimentally studied in the 2-300 K temperature range. The data reveal an anomalous contribution to the heat capacity at low temperatures. The value of this contribution is proportional to the first degree of temperature. It was identified that this anomaly in heat capacity is caused by the effect of disorder in the LuB50 crystalline structure and it can be described in the soft atomic potential model (SAP). The parameters of the approximation were determined. The temperature dependence of LuB50 heat capacity in the whole temperature range was approximated by the sum of SAP contribution, Debye and two Einstein components. The parameters of SAP contribution for LuB50 were compared to the corresponding values for LuB66, which was studied earlier. Negative thermal expansion at low temperatures was experimentally observed for LuB50. The analysis of the experimental temperature dependence for the Gruneisen parameter of LuB50 suggested that the low-frequency oscillations, described in SAP mode, are responsible for the negative thermal expansion. Thus, the glasslike character of the behavior of LuB50 thermal characteristics at low temperatures was confirmed.