Photolysis of Fluorinated Graphites with Embedded Acetonitrile Using a White-Beam Synchrotron Radiation

Fluorinated graphitic layers with good mechanical and chemical stability, polar C–F bonds, and tunable bandgap are attractive for a variety of applications. In this work, we investigated the photolysis of fluorinated graphites with interlayer embedded acetonitrile, which is the simplest representative of the acetonitrile-containing photosensitizing family. The samples were continuously illuminated in situ with high-brightness non-monochromatized synchrotron radiation. Changes in the compositions of the samples were monitored using X-ray photoelectron spectroscopy and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. The NEXAFS N K-edge spectra showed that acetonitrile dissociates to form HCN and N2 molecules after exposure to the white beam for 2 s, and the latter molecules completely disappear after exposure for 200 s. The original composition of fluorinated matrices CF0.3 and CF0.5 is changed to CF0.10 and GF0.17, respectively. The highly fluorinated layers lose fluorine atoms together with carbon neighbors, creating atomic vacancies. The edges of vacancies are terminated with the nitrogen atoms and form pyridinic and pyrrolic units. Our in situ studies show that the photolysis products of acetonitrile depend on the photon irradiation duration and composition of the initial CFx matrix. The obtained results evaluate the radiation damage of the acetonitrile-intercalated fluorinated graphites and the opportunities to synthesize nitrogen-doped graphene materials

Mitochondrial physiology

As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

Mitochondrial physiology

As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

Photolysis of Fluorinated Graphites with Embedded Acetonitrile Using a White-Beam Synchrotron Radiation

Fluorinated graphitic layers with good mechanical and chemical stability, polar C–F bonds, and tunable bandgap are attractive for a variety of applications. In this work, we investigated the photolysis of fluorinated graphites with interlayer embedded acetonitrile, which is the simplest representative of the acetonitrile-containing photosensitizing family. The samples were continuously illuminated in situ with high-brightness non-monochromatized synchrotron radiation. Changes in the compositions of the samples were monitored using X-ray photoelectron spectroscopy and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. The NEXAFS N K-edge spectra showed that acetonitrile dissociates to form HCN and N2 molecules after exposure to the white beam for 2 s, and the latter molecules completely disappear after exposure for 200 s. The original composition of fluorinated matrices CF0.3 and CF0.5 is changed to CF0.10 and GF0.17, respectively. The highly fluorinated layers lose fluorine atoms together with carbon neighbors, creating atomic vacancies. The edges of vacancies are terminated with the nitrogen atoms and form pyridinic and pyrrolic units. Our in situ studies show that the photolysis products of acetonitrile depend on the photon irradiation duration and composition of the initial CFx matrix. The obtained results evaluate the radiation damage of the acetonitrile-intercalated fluorinated graphites and the opportunities to synthesize nitrogen-doped graphene materials

Specific features of bronchial inflammation in asthma patients with airway hyper-responsiveness to cold and osmotic stimuli

Background. Excessive airway reaction to combined effects of environmental factors is very common in patients with asthma. The understanding of the molecular-cellular mechanisms of this hyperresponsiveness is very important.Aim. The aim of the work was to study granulocyte segment of bronchial inflammation in correlation with cytokine regulation and lipid peroxidation in patients with airway hyperresponsiveness to cold and osmotic stimuli.Materials and мethods. In 43 patients with partially controlled and uncontrolled persistent asthma with cold and osmotic airway hyperresponsiveness (group 1) asthma symptoms and lung function were assessed, the level of IL-5, IL-12 in exhaled breath condensate (EBC) and the total amount of myeloperoxidase (MPO) in induced sputum (IS) were measured; the number of neutrophils and eosinophils in smears of IS was counted. Basing on cytological and cytochemical analysis of smears of IS, the activity coefficients of MPO in granular leukocytes, the degree of cell destruction and the intensity of cytolysis were calculated. The contents of lipid hydroperoxide (LHP) and MPO in the blood serum were measured. A control group (group 2) consisted of asthma patients without airway reaction to cold and osmotic stimuli (11 people).Results. In the first group in comparison with the second one high levels of IL-12 were found (2,94 ± 0,09 vs. 2,53 ± 0,13 pg/mL; р = 0,024), IL-5 (3,64 ± 0,37 vs. 2,15 ± 0,14 pg/mL; р = 0,0001); the increase of neutrophils in IM (35,4 ± 3,5 vs. 17,2 ± 2,0%; р = 0,014); higher granulocytes cytolysis (0,38 ± 0,02 vs. 0,26 ± 0,02; р = 0,013), which correlated for neutrophils with the level of IL-12 (r = 0,46; р = 0,026); there was found out the increase of MPO concentration in IS (199,7 ± 49,0 vs. 81,4 ± 26,2 pixels; р = 0,039). The increased level of LHP in the blood serum correlated with the level of MPO in IS (r = 0,48; р = 0,039) and IL-5 in EBC (r = 0,71; р = 0,031).Conclusion. Airway hyperresponsiveness to cold and osmotic stimuli in patients with asthma is characterized by the relationship between the nature of Th1 and Th2 cytokine profile, the structure of granulocyte segment of bronchial inflammation, the enzymatic function of granulocytes, MPO activity and systemic formation of suboxidized lipid peroxidation products. Activation of granulocyte segment of inflammatory pattern in patients with asthma may be considered a factor of influence on the development and maintenance of airway hyperresponsiveness due to the escalation of oxidative stress and persistent inflammation

Современные подходы к ведению детей с атипичным гемолитико-уремическим синдромом

Experts of the Union of Pediatricians of Russia have developed modern guidelines on management of children with atypical hemolytic uremic syndrome (aHUS). aHUS is ultra-rare (orphan) disease with progressive and relapsing course during the life with potentially life-threatening state. This article covers issues of disease etiology, pathogenesis, and classification. Specific attention is paid to the diagnosis, differential diagnosis, and therapy of aHUS according to the evidence-based approaches.Экспертами Союза педиатров России разработаны актуальные клинические рекомендации по оказанию медицинской помощи детям с атипичным гемолитико-уремическим синдромом (аГУС). аГУС — ультраредкое (орфанное) заболевание прогрессирующего течения, характеризующееся рецидивированием на протяжении всей жизни и представляющее собой потенциально жизнеугрожающее состояние. В статье подробно рассмотрены вопросы этиологии, патогенеза, классификации заболевания. Особое внимание уделено диагностике, дифференциальной диагностике и терапии аГУС, основанным на принципах доказательности