Influence of strong π-acceptor ligands on Cr-K-edge X-ray absorption spectral signatures and consequences for the interpretation of surface sites in the Phillips catalyst.

X-ray absorption spectroscopy (XAS) has been central to the study of the Phillips polymerization catalyst (CrO/SiO). As Cr K-edge XAS signatures are sensitive to the oxidation state, geometry and types of ligands on surface (active) sites, the superposition of these effects makes their interpretation challenging. Notably, CO has been particularly used as a reductant to generate low valent Cr sites from CrO/SiO and as a structural IR probe for analysing reduced Cr surface sites.

Molecular Twist-Induced Single-Crystal Isomerization and Valence Tautomeric Transitions in a Cobalt-Dioxolene Complex.

A mononuclear valence tautomeric (VT) complex, [Co(pycz)(Sq)(Cat)] (1-trans), where pycz = 9-(pyridin-4-yl)-9H-carbazole, Sq⋅ = 3,5-di-tert-butyl-semiquinonato, and Cat = 3,5-di-tert-butyl-catecholato, is synthesized in the trans configuration, which undergoes one-step valence tautomeric transition above room temperature. Remarkably, 1-trans can transform into its isomeric structure, [Co(pycz)(Sq)(Sq)] (1-cis), at temperature above 350 K in a single-crystal-to-single-crystal way by in situ molecular twist, and the resulting 1-cis exhibits a pronounced two-step VT transition during magnetic measurements that is rare for mononuclear VT complexes. Such drastic solid-state structural transformation is reported in VT compounds for the first time, which is actuated by a crystal surface's melting-recrystallization induced phase transition process.

Spin transitions in ferric catecholate complexes mediated by outer-sphere counteranions.

A family of ionic ferric catecholate complexes 1-4 bearing a disubstituted 3,6-di--butyl-catecholate ligand (3,6-DBCatH) and tetradentate tris(2-pyridylmethyl)amine (TPA) was prepared and its spin transitions were investigated. Variation of the outer-sphere counteranions (PF, BPh, ClO, BF) is accompanied by changes in the magnetic behavior of the compounds under consideration. The crystal structures of complexes 1, 3 and 4 were determined by single crystal X-ray diffraction analysis at 100 K and 293 K.

Photoswitchable Zirconium MOF for Light-Driven Hydrogen Storage.

Here, we report a new photosensitive metal-organic framework (MOF) that was constructed via the modification of UiO-66-NH with diarylethene molecules (DAE, 4-(5-Methoxy-1,2-dimethyl-1H-indol-3-yl)-3-(2,5-dimethylthiophen-3-yl)-4-furan-2,5-dione). The material that was obtained was a highly crystalline porous compound. The photoresponse of the modified MOF was observed via UV-Vis and IR spectroscopy.

[The effect of enalapril maleate on the lipid peroxidation processes and on the body's antioxidant system in patients with hypertension].

Overall, forty-five patients with essential hypertension (EH) were examined. EH patients revealed dysbalance between lipid peroxidation and the antioxidant system. These disorders were found to correlate, to a certain extent, with severity of the malady, and to affect the character of the course of the process.

[Toxicity and antimicrobial properties of the new aminoglycoside antibiotic 535].

LD50 of antibiotic 535 (3'-desoxykanamycin C) on its intravenous, subcutaneous and oral administration to albino mice was 225, 1150 and at least 5000 mg/kg respectively. After a single subcutaneous administration to rabbits in a dose of 10 mg/kg antibiotic 535 was rapidly absorbed and detected in the blood and organs of the animals for 24 hours. The antibiotic was mainly excreted with the urine.

[Comparative study of the effects of carminomycin 13-cyclohexylidenehydrazone and carminomycin on several immunologic responses of the body].

The effect of carminomycin and 13-cyclohexylidenhydrazone of carminomycin (13-CHC) on some immunological reactions was studied comparatively on mice. It was shown that 13-CHC administered intravenously or orally had an immunodepressive effect on the synthesis of the antibodies to the sheep red blood cells. By the character of the immunodepressive effect on the humoral and transplantation immunity 13-CHC was close to carminomycin.

[Action of doxorubicin on immunogenesis].

The effect of doxorubicin, carminomycin and rubomycin on some immunological reactions was studied comparatively on mice. It was shown that doxorubicin had an immunodepressant effect on the synthesis of antibodies and antibody-forming cells. By the character of its immunodepressant effect doxorubicin was similar to rubomycin.

[Comparative study of the antibacterial activity of aminoglycoside antibiotics and their combinations with carbenicillin against Pseudomonas aeruginosa].

Antibacterial activity of 7 aminoglycoside antibiotics and combinations of tobramycin or gentamicin with carbenicillin was studied with respect to 33 clinical strains of Ps. aeruginosa. Tobramycin, sisomicin, gentamicin and amicacin showed high levels of antibacterial activity.

[Isolation and identification of the antibiotics amicetin and nebramycin formed by a Streptomyces coeruleoaurantiacus 4009 culture].

It was found that Str. coeruleoaurantiacus, strain 4009 produced antibiotics 4009-A and 4009-B belonging to different groups. Antibiotic 4009-A was identified as amicetin belonging to the group of pyrimidine bases and antibiotic 4009-B as the nebramycin complex belonging to the group of aminoglycosides.

[Effectiveness of the combined use of tobramycin with carbenicillin or cephalosporins in experimental infection in mice caused by Providencia stuartii].

Antibacterial activity of tobramycin in combination with carbenicillin or cephalosporins against 20 strains of Providencia stuartii was studied. The combinations of tobramycin with carbenicillin (1 : 2.5) or cephaloridine (1 : 1) were most active.

[Immunodepressive action of anthracycline antibiotics studied on 2 different transplantation immunity models].

The effect of carminomycin and rubomycin in equitoxic doses on the reaction of rejection of the allogenic skin graft and the reaction of the transplant to the host in mice (RTAH) was studied. Carminomycin significantly hampered the rejection of the skin graft and under certain conditions prevented development of the RTAH which indicated suppression of the formation of the clone of the immune T-killers. Rubomycin almost did not hamper the rejection of the skin graft and had no effect on the RTAH which indicated the absence of the selective effect on the system of K-killers.

[Development of antitumor immunity in animals treated with carminomycin].

Sensitivity of the mice inoculated with ascitic NK/Ly cells and cured with carminomycin to repeated inoculation with the same tumour was studied. It was found that curing with carminomycin was accompanied by development of resistance to the repeated inoculation. Such resistance might be transferred to intact singeneic mice with a suspension of the cells of the spleen or lymph nodes from unsusceptible donors.

[Combined action of rubomycin and diuretics on the induction of antibody synthesis in mice].

The effect of 2 diuretics, diacarb and lasix on the intensity of immunodepressant action of low doses of rubomycin was studied. It was shown that diacarb increased the inhibitory effect of rubomycin on accumulation of the antibody-forming cells in the spleen. This effect was evident by the 3rd, 4th and 7th day after the antigen injection to the mice (the 4th, 5th and 8th day after the last injection of rubomycin).

[Rapid change in the dynamics of antibody-forming cells under the influence of a single injection of various anthracyclines].

The dynamics of the titers and number of the antibody forming cells was studied within 26 hours after a single injection of anthracycline to immunized animals at various phases of the immune response. The specificity of the "rapid" effect of anthracyclines suggests that the low differentiated precursors of the antibody forming cells are the main target for the rubomycin effect and the immune competent cells in the state of multiplication and differentiation under the effect of the antigen are the main target for the carminomycin effect. The study was performed with noninbred mice immunized with sheep red cells.

[Immunodepressive action of carminomycin and rubomycin derivatives].

The immunodepressive effects of carminomycin and its 3 semi-synthetic derivatives, as well as rubomycin and its derivative R-103 were compared. It was found that 14-hydroxycarminomycin was much superior to the other substances in the experiments with synthesis induction suppression of antibodies against sheep red cells in mice. Suppression of the rejection of the skin allogenic grafts in the mice by carminomycin was higher as compared to that by the other substances.

[Comparison of the action of carminomycin and rubomycin on the dynamics of the primary and secondary immune responses].

The effect of rubomycin and carminomycin on the dynamics of the primary and secondary immune response and formation of the immunologic memory to sheep red cells in mice was studied. Differences in the character of the antibiotics effect indicative of the higher selective action of carminomycin on multiplying cells, precursors of the antibody-forming plasmids, were found. Theoretically interesting discrepancies in the effect of the antibiotics on the content of the antibodies in the serum and the antibody-producing cells in the spleen were shown.

[Antiviral action of carminomycin and some of its derivatives].

Carminomycin was shown to inhibit the development of both the DNA-containing variolovaccine virus and the RNA-containing grippe virus in chick embryos. Comparison of the effects of rubomycin, carminomycin, 14-oxy-carminomycin and carminomycin complex with bovine serum albumin in experiments with chick embryos showed that the inhibitory effect of carminomycin and its derivatives on the development of the grippe virus was much higher than that of rubomycin. The carminomycin derivatives proved to be much more active in this respect than the initial antibiotic.

[Effect of the peroral use of the antitumor antibiotic, carminomycin, on the immunological reactivity of the body of animals].

Carminomycin administered orally to mice for many times in doses of 2.5 and 1.25 mg/kg induced suppression of hemagglutinine production to sheep erythrocytes and formation of immunologically competent cells in the spleen of test animals.

[Study of the effect of rifampicin on certain immunological and protective reactions of the body].

The effect of rifampicin on formation of hemagglutinins in mice in response to administration of sheep erythrocytes was studied. The experiments showed that rifampicin administered orally in doses 10-25 times higher than the therapeutic ones did not suppress formation of the antibodies and protective mechanisms of the organism. The antibiotic did not lower the absorbing capacity of the cells by the reticuloendothelial system and the rate of phagocytosis by the leucocytes of the peritoneal exudate in mice.