Magnetic properties of polymerized C60_{60} with Fe

We provide evidence that high-pressure high-temperature (2.5 GPa and 1040 K) treatment of mixtures of iron with fullerene powders leads to the complete transformation of iron into iron carbide Fe$_3$C. The comparison of the magnetic properties (Curie temperature and magnetic moment) of the here studied samples and those for the ferromagnetic polymer Rh-C$_{60}$ indicates that the main ferromagnetic signal reported in those samples is due to Fe$_3$C and not related to the ferromagnetism of carbon as originally interpreted. Taking into account the results obtained in this study the original paper on ``Magnetic carbon" (Nature {\bf 413}, 716 (2001)) was recently retracted.Comment: 5 Figures, 4 page

Covalent Organic Framework (COF-1) under High Pressure

COF-1 has a structure with rigid 2D layers composed of benzene and B3O3 rings and weak van der Waals bonding between the layers. The as-synthesized COF-1 structure contains pores occupied by solvent molecules. A high surface area empty-pore structure is obtained after vacuum annealing. High-pressure XRD and Raman experiments with mesitylene-filled (COF-1-M) and empty-pore COF-1 demonstrate partial amorphization and collapse of the framework structure above 12–15 GPa. The ambient pressure structure of COF-1-M can be reversibly recovered after compression up to 10–15 GPa. Remarkable stability of highly porous COF-1 structure at pressures at least up to 10 GPa is found even for the empty-pore structure. The bulk modulus of the COF-1 structure (11.2(5) GPa) and linear incompressibilities (k[100]=111(5) GPa, k[001]=15.0(5) GPa) were evaluated from the analysis of XRD data and cross-checked against first-principles calculations.\ua0\ua9 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinhei

Hydrogen storage in high surface area graphene scaffolds

Using an optimized KOH activation procedure we prepared highly porous graphene scaffoldmaterials with SSA values up to 3400m² g⁻¹ and a pore volume up to 2.2 cm³ gˉ¹, which are among the highest for carbon materials. Hydrogen uptake of activated graphene samples was evaluated in a broad temperature interval (77–296 K). After additional activation by hydrogen annealing the maximal excess H2 uptake of 7.5 wt% was obtained at 77 K. A hydrogen storage value as high as 4 wt% was observed already at 193 K (120 bar H₂), a temperature of solid CO₂, which can be easily maintained using common industrial refrigeration methods

Magnetic properties of carbon phases synthesized using high pressure-high temperature treatment

Two sets of samples were synthesized at 3.5 GPa near the point of C60 cage collapse at different annealing times. A clear structural transformation from mixture of C60 polymeric phases to graphite-like hard carbon phase was confirmed by X-ray diffraction and Raman spectroscopy. Magnetic force microscopy and superconducting quantum interference device were used to characterize the magnetic properties of the synthesized samples. We found that the sample preparation conditions used in this study are not suitable to produce bulk magnetic carbon.Comment: 26 pages, 7 figure

Taxonomical Study and Diversity of Rotifers in Chikkadevarayana Canal of Cauvery River, Karnataka, India

The study was undertaken to assess the diversity and taxonomical observations of rotifers in Chikkadevaraya canal (CDC). The investigation revealed that 27 species belonging to 15 genera and 9 families coming under 3 orders and 2 classes, were observed, photographed and also identified up to species level and are reported for the first time in this region. Among 22 genera of rotifers, the maximum of 11 species belonged to family Brachionidae followed by 5 species from family Lecanidae, 2 species of Euchlanidae, Collurellidae, Notommatidae and Philodinidae respectively. One species each from family Trichocercidae, Testudinellidae and Filinidae. The genus Brachionus, Keratella and Euchlanis was found in all the five sampling points. Euchlanis dialata was abundant while Macrotrachela quadricornifera was found to be least. Species abundance was higher at Gandehosahalli followed by Darsaguppe, Kannalu, Edmuri and lowest in Pandavapura sampling stations. Shannon�s diversity was also found to be highest at Gandehosahalli (2.63) while low in Pandavapura (1.78). The samples of water were used to conduct physico-chemical parameters like temperature, electrical conductivity, pH, dissolved oxygen, total alkalinity, total hardness, chlorides, total solids, total dissolved solids, total suspended solids, sulphate, phosphate and nitrate etc. Statistical interpretations of data were presented based on correlation analysis. The population of rotifes were positively correlated with pH, total alkalinity, hardness and negativly correlated with total suspended solids and total solids of water sample

Raman scattering in C_{60} and C_{48}N_{12} aza-fullerene: First-principles study

We carry out large scale {\sl ab initio} calculations of Raman scattering activities and Raman-active frequencies (RAFs) in ${\rm C}_{48}{\rm N}_{12}$ aza-fullerene. The results are compared with those of ${\rm C}_{60}$. Twenty-nine non-degenerate polarized and 29 doubly-degenerate unpolarized RAFs are predicted for ${\rm C}_{48}{\rm N}_{12}$. The RAF of the strongest Raman signal in the low- and high-frequency regions and the lowest and highest RAFs for ${\rm C}_{48}{\rm N}_{12}$ are almost the same as those of ${\rm C}_{60}$. The study of ${\rm C}_{60}$ reveals the importance of electron correlations and the choice of basis sets in the {\sl ab initio} calculations. Our best calculated results for ${\rm C}_{60}$ with the B3LYP hybrid density functional theory are in excellent agreement with experiment and demonstrate the desirable efficiency and accuracy of this theory for obtaining quantitative information on the vibrational properties of these molecules.Comment: submitted to Phys.Rev.

Применение Антитромбина-III при новой коронавирусной инфекции (Covid-19) в условиях экстракорпоральной мембранной оксигенации (клиническое наблюдение)

COVID-19 is a disease that, in addition to respiratory failure, leads to thrombosis and bleeding due to coagulation disorders. Extracorporeal membrane oxygenation (ECMO), required in cases of a deterioration of gas exchange function of the lungs, contributes to changes in blood coagulation indicators, which leads to an increased risk of hemorrhagic complications and thrombosis. In the article, a clinical case of a severe course of COVID-19 is reported, which required ECMO. During the treatment, antithrombin-III was used, which allowed avoiding life-threatening complications and successfully completing the procedure. COVID-19 является заболеванием, приводящим помимо дыхательной недостаточности к тромбозам и кровотечениям вследствие нарушений в системе гемостаза. Экстракорпоральная мембранная оксигенация (ЭКМО), требующаяся при снижении газообменной функции легких, вносит свой вклад в изменения показателей свертывания крови, что ведет к увеличению риска осложнений геморрагического характера и тромбозов. В статье представлен клинический случай тяжелого течения COVID-19, потребовавший проведения ЭКМО. В ходе лечения был использован Антитромбин-III, что позволило избежать жизнеугрожающих осложнений и успешно завершить процедуру.

Опыт применения инвазивного гемодинамического мониторинга с помощью пре- и транспульмональной термодилюции при трансплантации легких

Objective: to demonstrate the experience of using complex hemodynamic monitoring by means of prepulmonary thermodilution (PPTD) and transpulmonary thermodilution (TPTD) – PiCCO – in lung transplantation (LTx). Materials and methods. Presented is a clinical case study of a 51-year-old patient with the following diagnosis: severe bronchiectasis and type 3 respiratory failure. Bilateral lung transplantation was performed at Sklifosovsky Research Institute for Emergency Medicine, Moscow. Intraoperative hemodynamic monitoring was performed using PPTD and TPTD techniques. Conclusion. The case study presented shows that simultaneous use of PPTD and TPTD for hemodynamic monitoring during lung transplantation achieves better treatment outcomes. This hemodynamics monitoring strategy is highly informative, allows for continuous measurement of necessary hemodynamic parameters and for timely and targeted correction of identified disorders by influencing the basic pathogenesis links of cardiovascular disease.Цель. Показать опыт использования комплексного гемодинамического мониторинга с помощью при- менения пре- и транспульмональной термодилюции (PiCCO) при трансплантации легких. Материалы и методы. Представлено клиническое наблюдение пациентки 51 года с диагнозом «бронхоэктатическая болезнь, тяжелое течение; дыхательная недостаточность 3-й степени». Была выполнена двусторонняя трансплантация легких в ГБУЗ «НИИ СП им. Н.В. Склифосовского». Интраоперационный гемодинамический мониторинг осуществлялся с помощью методов пре- и транспульмональной термодилюции. Заключение. Клиническое наблюдение показывает целесообразность одновременного использования пре- и транспульмональной термодилюции с целью гемодинамического мониторинга во время трансплантации легких для улучшения результатов лечения. Данный метод мониторинга гемодинамики обладает высокой информативностью, позволяет осуществлять непрерывное измерение необходимых параметров гемодинамики, своевременно и целенаправленно корригировать выявленные нарушения за счет воздействия на основные звенья патогенеза сердечно-сосудистой недостаточности

NMR-Based Structural Modeling of Graphite Oxide Using Multidimensional 13C Solid-State NMR and ab Initio Chemical Shift Calculations

Chemically modified graphenes and other graphite-based materials have attracted growing interest for their unique potential as lightweight electronic and structural nanomaterials. It is an important challenge to construct structural models of noncrystalline graphite-based materials on the basis of NMR or other spectroscopic data. To address this challenge, a solid-state NMR (SSNMR)-based structural modeling approach is presented on graphite oxide (GO), which is a prominent precursor and interesting benchmark system of modified graphene. An experimental 2D C-13 double-quantum/single-quantum correlation SSNMR spectrum of C-13-labeled GO was compared with spectra simulated for different structural models using ab initio geometry optimization and chemical shift calculations. The results show that the spectral features of the GO sample are best reproduced by a geometry-optimized structural model that is based on the Lerf-Klinowski model (Lerf, A. et al. Phys. Chem. B 1998, 102, 4477); this model is composed of interconnected sp(2), 1,2-epoxide, and COH carbons. This study also convincingly excludes the possibility of other previously proposed models, including the highly oxidized structures involving 1,3-epoxide carbons (Szabo, I. et al. Chem. Mater. 2006, 18, 2740). C-13 chemical shift anisotropy (CSA) patterns measured by a 2D C-13 CSA/isotropic shift correlation SSNMR were well reproduced by the chemical shift tensor obtained by the ab initio calculation for the former model. The approach presented here is likely to be applicable to other chemically modified graphenes and graphite-based systems