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1.
Sci Rep ; 13(1): 2169, 2023 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-36750645

RESUMO

Lithium-ion batteries based on high-voltage cathode materials, such as LiCoPO4, despite being promising in terms of specific power, still suffer from poor cycle life due to the lower stability of common non-aqueous electrolytes at higher voltages. One way to overcome this issue might be decreasing the working potential of the battery by doping LiCoPO4 by Fe, thus reducing electrolyte degradation upon cycling. However, such modification requires a deep understanding of the structural behavior of cathode material upon lithiation/delithiation. Here we used a combination of operando synchrotron-based XRD and XAS to investigate the dynamics of d-metal local atomic structure and charge state upon cycling of LiCo0.5Fe0.5PO4 mixed d-metal olivine cathode material. Principal components analysis (PCA) of XAS data allowed the extraction of spectra of individual phases in the material and their concentrations. For both Co and Fe two components were extracted, they correspond to fully lithiated and delithiated phases of LixMPO4 (where M = Fe, Co). Thus, we were able to track the phase transitions in the material upon charge and discharge and quantitatively analyze the M2+/M3+ electrochemical conversion rate for both Fe and Co. Rietveld's refinement of XRD data allowed us to analyze the changes in the lattice of cathode material and their reversibility upon (de)lithiation during cycling. The calculation of DFT and Bader charge analysis expects the oxygen redox procedure combined with d-metals redox, which supplements iron charge variations and dominates at high voltages when x < 0.75 in LixCoFePO4.

2.
J Phys Condens Matter ; 33(21)2021 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-33588394

RESUMO

Valence tautomer transition occurs mainly in 3d metalorganic complexes with redox-active ligands and makes them potential candidates for single-molecular switches. The transition occurs under temperature, pressure, or light-induced stimuli and is strongly affected by the intermolecular interactions. However single-crystal x-ray diffraction is not always applicable to such systems when crystal structure is destroyed upon transition or system is studied in the solution. Such an example is bis(o-semiquinonato) cobalt complex with TEMPO-functionalized iminopyridine ancillary ligand. In this work we apply two complementary techniques-ligand-sensitive Fourier transform infrared spectroscopy (FTIR) and metal sensitive Co K-edge x-ray absorption spectroscopy (XAS). In a solid state, a temperature hysteresis of magnetization larger than 40 K was observed upon cyclic cooling-heating. So, the temperature of phase transition upon cooling is about 40 K lower than that upon heating. In solution, the x-ray absorption spectra for high-temperature and low-temperature states were similar to that in the solid form, but the hysteresis was absent. Two methods are can probe valence tautomer transition, but XAS has an advantage for the liquid phase analysis and FTIR has larger sensitivity to the ligand related interactions in solid.

3.
J Phys Chem B ; 123(6): 1324-1331, 2019 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-30657324

RESUMO

Thermal and photoinduced processes accompanying complexation of photochromic spiropyrans (SPP) with Zn ions in acetone solution were characterized by means of UV-vis and X-ray absorption spectroscopies in operando regime. SPP ligands are usually transparent at λ > 350 nm, but after mixing with Zn ions, they produce a stable colored (ε = 32 000-38 000 M-1 cm-1) complex with maximum absorption at 525 nm, which makes them a powerful tool for monitoring metal-ion concentration in solution. The complex revealed fluorescence and photochromic behavior under static irradiation with visible light with constant photoreaction quantum yield across its characteristic absorption band. Zn K-edge X-ray absorption spectra show prominent changes in Zn local atomic structure between free Zn ions and Zn complex. The pump-flow-probe scheme was adapted to measure operando changes in Zn coordination upon light irradiation. Within experimental time resolution, we have determined that 20 µs after light irradiation, Zn ion is released out of the complex. This is the first example of the direct spectroscopic probe of the Zn photorelease from the spiropyran complex.

4.
Dalton Trans ; 48(2): 752, 2019 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-30542689

RESUMO

Correction for 'New ferrocene-based 2-thio-imidazol-4-ones and their copper complexes. Synthesis and cytotoxicity' by D. A. Guk et al., Dalton Trans., 2018, DOI: 10.1039/c8dt03164a.

5.
Dalton Trans ; 47(48): 17357-17366, 2018 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-30480670

RESUMO

Synthesis, characterization (HRMS, NMR, EPR, XANES, UV-Vis spectroscopy, and electrochemistry), DNA and BSA binding and in vitro biological screening of two new ferrocene-incorporated thiohydantoin derivatives (5 and 6) and their copper coordination compounds are reported. The ferrocene-based thiohydantoin derivatives were prepared by copper-catalyzed azide alkyne cycloaddition reactions between alkynyl ferrocenes and 5-(Z)-3-(2-azidoethyl)-2-(methylthio)-5-(pyridin-2-ylmethylene)-1H-imidazol-4H-one. Alkynyl ferrocenes necessary for these syntheses were prepared by new procedures. Intermolecular redox reactions between the ferrocene fragment and copper(+2) coordinated ions were studied by different methods to determine the mechanism and kinetic constants of redox processes. Ferrocene-containing imidazolones (5 and 6) and their copper complexes were also tested for their in vitro cytotoxic activity against MCF-7 and A-549 carcinoma cells, and also against the noncancerous cell line Hek-293. The results showed modest cytotoxicity against the subjected cancer cell line compared with cisplatin. The ability of the obtained compounds to cause DNA degradation and cell apoptosis was investigated, and the distribution of cytosol/pellets was studied by AAS.


Assuntos
Antineoplásicos/farmacologia , Complexos de Coordenação/farmacologia , Cobre/farmacologia , Inibidores Enzimáticos/farmacologia , Imidazóis/farmacologia , Metalocenos/farmacologia , Telomerase/antagonistas & inibidores , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Bovinos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Complexos de Coordenação/síntese química , Complexos de Coordenação/química , Cobre/química , Clivagem do DNA , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Células HEK293 , Humanos , Imidazóis/síntese química , Imidazóis/química , Metalocenos/química , Estrutura Molecular , Soroalbumina Bovina/química , Relação Estrutura-Atividade , Telomerase/metabolismo
6.
Aviakosm Ekolog Med ; 50(6): 70-78, 2016.
Artigo em Inglês, Russo | MEDLINE | ID: mdl-29553609

RESUMO

The paper presents an algorithm of cardio complex classification as part of processing the data of continuous cardiac monitoring. R-wave detection concurrently with cardio complex sorting is discussed. The core of this approach is the use of prior information about. cardio complex forms, segmental structure, and degree of kindness. Results of the sorting algorithm testing are provided.


Assuntos
Medicina Aeroespacial , Sistema Cardiovascular/fisiopatologia , Monitorização Fisiológica/métodos , Algoritmos , Humanos , Modelos Teóricos , Voo Espacial
8.
J Phys Condens Matter ; 22(24): 245504, 2010 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-21393785

RESUMO

Spectroscopic investigations of a ZnAl(2)O(4) spinel doped with bivalent copper ions of 0.05% concentration have been carried out in the temperature range 4.2-290 K using a 3 cm(-1) range electron paramagnetic resonance (EPR) spectrometer having an operational frequency f = (9.241 ± 0.001) GHz. The spectrum can be represented as a superposition of two components: a low-temperature (LT) and a high-temperature (HT) one. Redistribution of integrated intensity between HT and LT components of the spectra occurs with temperature change that is typical of systems with multi-minimum adiabatic potential. Spectra observed are explained within the modified theory of crystalline field (MTCF). The electron levels of a Cu(2+) ion placed in an octahedral coordination center with trigonal distortion [CuO(6)](10-) have been calculated. The influence of possible types of oxygen octahedron distortions and possible displacement of copper ions from the symmetry center on the electron spectrum, as well as the shape of the adiabatic potential, has been analyzed. It is shown that in the low-temperature phase the multiple minima of the adiabatic potential occur due to tetragonal distortions while the depth of a minimum is determined by the degree of trigonal octahedron distortions. Tetragonal distortion values and multi-minimum potential barrier heights have been determined.

9.
Med Tekh ; (3): 18-21, 2005.
Artigo em Russo | MEDLINE | ID: mdl-16106954

RESUMO

The complicated situation in pediatric healthcare and long-term negative trends observed in the health of children predetermined the necessity of introducing automated units built on the principles of preventive medicine and screening diagnostics into the practice of healthcare. AKDO units belong to such equipment designed for early diversified diagnostics of chronic diseases made within comprehensive examinations of children, i.e. a state program of regular medical check-ups of children. The paper presents objective trends taking place in the modern practical healthcare that necessitated principle changes in and promotion of functional potentialities of the existing ASPON systems developed in 1983-1988.


Assuntos
Diagnóstico por Computador/métodos , Programas de Rastreamento/métodos , Adolescente , Criança , Diagnóstico por Computador/economia , Diagnóstico Diferencial , Dieta , Eletrocardiografia , Humanos , Programas de Rastreamento/economia , Programas de Rastreamento/instrumentação , Pais , Reologia , Federação Russa , Inquéritos e Questionários
10.
Urologiia ; (2): 35-9, 2005.
Artigo em Russo | MEDLINE | ID: mdl-15989025

RESUMO

Long-term results of conservative treatment of 153 patients with invasive cancer of the urinary bladder were studied retrospectively. The patients had stage T2 (n=121, 79.1%), T3 (n=26, 17%), T4 (n=6, 3.9%). All the patients had transitional cell cancer. GI, G2 and G3 tumors were registered in 104 (68%), 35 (24%) and 12 (8%) cases, respectively. 88 (57.5%) patients received combined treatment, 65 (42.5%) patients--only surgery. In the patients with a small invasive tumor of the urinary bladder subjected to surgery alone (TUR-vaporization), overall 5-year survival was 70.4%. In patients with advanced cancer of the urinary bladder who had received curative radiotherapy in case of superficial residual tumor had TUR-vaporization of the urinary bladder overall 5-year survival was 76.5%. In patients exposed to large-fraction (TFD 20-25 Gy) preoperative radiotherapy followed by TUR-vaporization, survival at this moment was 84.6%. Three-year overall and recurrence-free survival at stage T2 was 97.5 and 47.4%, respectively; at stage T3 and T4 overall 3-year survival was 57.1 and 26.6%, respectively. Thus, the conclusion is that transurethral electrosurgery in conservative therapy of patients with invasive cancer of the urinary bladder is a promising approach.


Assuntos
Carcinoma de Células de Transição/cirurgia , Endoscopia/métodos , Neoplasias da Bexiga Urinária/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células de Transição/mortalidade , Carcinoma de Células de Transição/patologia , Quimioterapia Adjuvante , Terapia Combinada , Intervalo Livre de Doença , Eletrocirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Metástase Neoplásica , Radioterapia Adjuvante , Estudos Retrospectivos , Neoplasias da Bexiga Urinária/mortalidade , Neoplasias da Bexiga Urinária/patologia
11.
Med Tekh ; (2): 27-31, 2002.
Artigo em Russo | MEDLINE | ID: mdl-12063784

RESUMO

The paper deals with the informational approach to assessing the quality of formalized medical documents. It shows it possible to apply the above approach to analyzing the components of medical support of automatic diagnostic systems.


Assuntos
Prontuários Médicos/normas , Automação
12.
Med Tekh ; (1): 3-7, 2002.
Artigo em Russo | MEDLINE | ID: mdl-11898660

RESUMO

Experience in designing and using screening diagnostic systems has yielded a formal model of an automatic system to make a prophylactic surveys of the population. This model makes it possible to design automatic systems so that a number of informational structures should be developed to store initial medical data and the results of their processing, to aggregate decisive rules of making a conclusion on the health status and the relatively invariant interpreting core. The similar approach substantially simplifies a procedure to modify decisive rules from the results of using the system and to duplicate off-the shelf solutions on different quota of patients with minimal changes in software implementation.


Assuntos
Programas de Rastreamento/instrumentação , Vigilância da População , Medicina Preventiva , Adolescente , Automação , Criança , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Federação Russa
13.
Fiziol Zh (1994) ; 45(3): 114-7, 1999.
Artigo em Ucraniano | MEDLINE | ID: mdl-10439301

RESUMO

There are studying the symptoms of development catalepsy at new home preparation, which is having the butirophenone's derivative. There are shown that the time development and manifestation of catalepsy are depending from preparation's dose: 0.1 mg/kg-1.3 mg/kg (maximum) -10 mg/kg in intravenous introduction and 1.2 mg/kg-3.5 mg/kg (maximum)-40 mg/kg in intraperitoneal introduction.


Assuntos
Antipsicóticos/farmacologia , Catalepsia/induzido quimicamente , Haloperidol/farmacologia , Animais , Antipsicóticos/administração & dosagem , Antipsicóticos/toxicidade , Relação Dose-Resposta a Droga , Feminino , Haloperidol/administração & dosagem , Haloperidol/toxicidade , Injeções Intraperitoneais , Injeções Intravenosas , Dose Letal Mediana , Masculino , Camundongos , Fatores de Tempo
14.
Lik Sprava ; (1): 124-6, 1999.
Artigo em Ucraniano | MEDLINE | ID: mdl-10424023

RESUMO

Children affected by acute virus respiratory infection running its course with characteristic symptoms of rhinitis, pharyngitis, tonsillitis, and acute bronchitis were administered combination therapy with a new pharmaceutical valcophen in a tablet form. In a clinical trial of the above drug, gratifying therapeutic results were found to be obtainable with a 2-to-3 day course of treatment at minimum dosage.


Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Aspirina/uso terapêutico , Cafeína/uso terapêutico , Fenobarbital/uso terapêutico , Doença Aguda , Adolescente , Criança , Pré-Escolar , Combinação de Medicamentos , Quimioterapia Combinada , Feminino , Humanos , Masculino , Transtornos Neuróticos/complicações , Infecções Respiratórias/tratamento farmacológico , Comprimidos , Viroses/tratamento farmacológico
15.
Fiziol Zh (1994) ; 44(5-6): 102-5, 1998.
Artigo em Ucraniano | MEDLINE | ID: mdl-9866032

RESUMO

Tablets valcophen, which are containing the pyrimidine's derivative, have an acute anticonvulsive activity. Tablets valcophen and granules phenobarbital for children are having the same activity, which have been marked about lower intensity convulsions, quantity of a lived animals and also lengthening a time of deathing mice. These investigations are showing that tablets valcophen may be used for treatment convulsive state in children.


Assuntos
Anticonvulsivantes/uso terapêutico , Aspirina/uso terapêutico , Cafeína/uso terapêutico , Fenobarbital/uso terapêutico , Tetania/tratamento farmacológico , Animais , Criança , Convulsivantes , Relação Dose-Resposta a Droga , Combinação de Medicamentos , Avaliação Pré-Clínica de Medicamentos , Humanos , Camundongos , Pentilenotetrazol , Comprimidos , Tetania/induzido quimicamente
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