MoVN-Cu Coatings for In Situ Tribocatalytic Formation of Carbon-Rich Tribofilms in Low-Viscosity Fuels.

Inhibiting the tribological failure of mechanical assemblies which rely on fuels for lubrication is an obstacle to maintaining the lifetime of these systems with low-viscosity and low-lubricity fuels. In the present study, a MoVN-Cu nanocomposite coating was tribologically evaluated for durability in high- and low-viscosity fuels as a function of temperature, load, and sliding velocity conditions. The results indicate that the MoVN-Cu coating is effective in decreasing wear and friction relative to an uncoated steel surface.

[Transcatheter aortic valve replacement after Ozaki procedure].

The Ozaki operation is currently considered to be a sufficiently known surgical procedure performed in aortic valve defects. Despite satisfactory results in the mid-term period after neocuspidalization, there have been reported cases of pronounced aortic insufficiency due to rupture of neocusps or their endocarditis. Transcatheter aortic valve replacement is a rapidly developing trend at the junction of modern cardiac surgery and interventional cardiology, expansively covering groups of patients at high, moderate and recently also low surgical risk.

Open transaortic implantation of 'Medlab-KT' prosthesis.

Aim: The study was aimed at comparing the immediate clinical and haemodynamic results of open implantation of the balloon-expandable aortic prosthesis 'MedLab-KT' with the respective parameters of standard replacement of the aortic valve by a mechanical prosthesis in high-risk surgical patients.

Patients And Methods: We analysed a total of 209 cases of prosthetic repair of the aortic valve. The Study Group comprised 28 patients subjected to open implantation of the 'MedLab-KT' prosthesis in conditions of extracorporeal circulation and myocardial ischaemia and belonging to a high-surgical risk cohort.

[First serial transcatheter implantation of pulmonary valve using MedLab-KT prosthesis].

Background: Surgical treatment of 'blue' congenital heart defects frequently implies various interventions on the outlet portion of the right ventricle or pulmonary artery trunk. Most often used are various conduits, reconstructing the outlet portion of the right ventricle and pulmonary artery. Most patients having previously endured the mentioned interventions, would in the remote terms require repeat operative procedures for stenosis or insufficiency on the pulmonary valve or the implanted conduit.

Cyclopropenylidenes as Strong Carbene Anchoring Groups on Au Surfaces.

The creation of stable molecular monolayers on metallic surfaces is a fundamental challenge of surface chemistry. N-Heterocyclic carbenes (NHCs) were recently shown to form self-assembled monolayers that are significantly more stable than the traditional thiols on Au system. Here we theoretically and experimentally demonstrate that the smallest cyclic carbene, cyclopropenylidene, binds even more strongly than NHCs to Au surfaces without altering the surface structure.

[Transcatheter replacement of pulmonary artery valve with a graft containing polytetrafluoroethylene leaflets].

Annually, many operations for repeat prosthetic reconstruction of the pulmonary artery valve are performed due to dysfunction after primary correction of both congenital and acquired heart defects. Open operations with artificial circulation are associated with a high surgical risk. Transcatheter implantation is a new and progressive technique of heart valve replacement.

[Transcatheter valve-in-valve implantation of the 'MedLab-KT' prosthesis].

Valve-in-valve repeat prosthetic reconstruction is a less invasive alternative to 'open' redo operation for degenerative dysfunction of an aortic bioprosthesis. At the beginning of the history of using this method it was resorted to only in cases of high surgical risk, involving virtually inoperable patients. Currently, the world experience numbers in thousands of such interventions, known to be also performed in patients not belonging to a high-risk group.

H-shaped partial splenorenal shunting with the use of a reinforced graft made of porous polytetrafluoroethylene.

Aim: The study was aimed at improving the immediate and remote results of splenorenal bypass grafting.

Patients And Methods: A total of 57 patients presenting with hepatic cirrhosis, portal hypertension, and recurrent haemorrhage from oesophageal varices underwent an H-shaped partial splenorenal shunt procedure using an externally reinforced 1.5-2.

TiCaPCON-Supported Pt- and Fe-Based Nanoparticles and Related Antibacterial Activity.

A rapid increase in the number of antibiotic-resistant bacteria urgently requires the development of new more effective yet safe materials to fight infection. Herein, we uncovered the contribution of different metal nanoparticles (NPs) (Pt, Fe, and their combination) homogeneously distributed over the surface of nanostructured TiCaPCON films in the total antibacterial activity toward eight types of clinically isolated bacterial strains ( K261, B1079k/17-3, B1280A/17, no. 839, i5189-1, Ya-235: VanA, I-237: VanA, and U20) taking into account various factors that can affect bacterial mechanisms: surface chemistry and phase composition, wettability, ion release, generation of reactive oxygen species (ROS), potential difference and polarity change between NPs and the surrounding matrix, formation of microgalvanic couples on the sample surfaces, and contribution of a passive oxide layer, formed on the surface of films, to general kinetics of the NP dissolution.

Photonic crystallization of two-dimensional MoS for stretchable photodetectors.

Low temperature synthesis of high quality two-dimensional (2D) materials directly on flexible substrates remains a fundamental limitation towards scalable realization of robust flexible electronics possessing the unique physical properties of atomically thin structures. Herein, we describe room temperature sputtering of uniform, stoichiometric amorphous MoS2 and subsequent large area (>6.25 cm2) photonic crystallization of 5 nm 2H-MoS2 films in air to enable direct, scalable fabrication of ultrathin 2D photodetectors on stretchable polydimethylsiloxane (PDMS) substrates.

Immediate results of bypass grafting of the territory of the right coronary artery using the 'Penza Coronary Technology'.

Coronary artery bypass grafting (CABG) is known to be an effective method of treatment for multivessel obstructive coronary disease with low rates of reintervention and excellent long-term survival and freedom from angina. Graft patency lies at the heart of its procedural success and durability, which in its turn largely depends on the appropriate choice of the conduit, as well as the target coronary artery (CA). It should be mentioned that patency of one and the same conduit used for bypass grafting of the territory of either the left or right coronary artery (LCA and RCA, respectively) may differ, which is probably determined by differences in physiology, size, territory of runoff, and local flow characteristics between different coronary targets.

Indications for ascending aorta-bifemoral bypass grafting in patients with IHD and occlusion of the infrarenal aorta.

The problem concerning surgical decision-making in patients with significant atherosclerotic lesions of arteries of more than one basin will, probably, be important for cardiovascular surgeons for more than one decade. Even the centres possessing experience in several thousand cases of successful treatment of multifocal atherosclerosis have from time to time been facing non-trivial clinical situations requiring a non-standard decision the recommendations for which could hardly be found in the guidelines available, if at all. This article describes the technique and immediate results of an operation making it possible to simultaneously carry out revascularization of the myocardium and lower limbs in patients diagnosed as having a critical coronary lesion and Leriche syndrome with no intervention on the abdominal portion of the aorta.

Effect of Substrate Support on Dynamic Graphene/Metal Electrical Contacts.

Recent advances in graphene and other two-dimensional (2D) material synthesis and characterization have led to their use in emerging technologies, including flexible electronics. However, a major challenge is electrical contact stability, especially under mechanical straining or dynamic loading, which can be important for 2D material use in microelectromechanical systems. In this letter, we investigate the stability of dynamic electrical contacts at a graphene/metal interface using atomic force microscopy (AFM), under static conditions with variable normal loads and under sliding conditions with variable speeds.

Structure and antibacterial properties of Ag-doped micropattern surfaces produced by photolithography method.

Photolithography methods offer ample opportunities for creating biological surface patterns over large areas. Herein, samples with patterned surface having the same Ag total coverage area and content, but different surface topography made of periodically spaced Ag/Si pillars with a diameter of 10 and 50 μm and a height of 3, 1, and 0.2 μm were produced by photolithography technique and studied to uncover the dependences of bactericide ion release on surface topography and antibacterial effect on Ag ion concentration.

Two-Dimensional Hierarchical Semiconductor with Addressable Surfaces.

Surfaces play a key role in determining material properties, and their importance is further magnified in the two-dimensional (2D) limit. Though monolayers are entirely composed of surfaces, there is no chemical approach to covalently address them without breaking intralayer bond. Here, we describe a 2D semiconductor that offers two unique features among 2D materials: structural hierarchy within the monolayer and surface reactive sites that enable functionalization.

Hexagonal MoTe with Amorphous BN Passivation Layer for Improved Oxidation Resistance and Endurance of 2D Field Effect Transistors.

Environmental and thermal stability of two-dimensional (2D) transition metal dichalcogenides (TMDs) remains a fundamental challenge towards enabling robust electronic devices. Few-layer 2H-MoTe with an amorphous boron nitride (a-BN) covering layer was synthesized as a channel for back-gated field effect transistors (FET) and compared to uncovered MoTe. A systematic approach was taken to understand the effects of heat treatment in air on the performance of FET devices.

Multifunctional Vesicles from a Self-assembled Cluster-Containing Diblock Copolymer.

We describe a new diblock copolymer composed of two segments with complementary functionalities. One block contains pendent photo-cross-linkable cinnamoyl groups, and the other contains molecular clusters, CoSe, capable of multielectron redox processes. This multifunctional macromolecule is synthesized by sequential ring-opening metathesis polymerization of monomers constructed using norbornene moieties.

Versatile technique for assessing thickness of 2D layered materials by XPS.

X-ray photoelectron spectroscopy (XPS) has been utilized as a versatile method for thickness characterization of various two-dimensional (2D) films. Accurate thickness can be measured simultaneously while acquiring XPS data for chemical characterization of 2D films having thickness up to approximately 10 nm. For validating the developed technique, thicknesses of few-layer graphene (FLG), MoS and amorphous boron nitride (a-BN) layer, produced by microwave plasma chemical vapor deposition (MPCVD), plasma enhanced chemical vapor deposition (PECVD), and pulsed laser deposition (PLD) respectively, were accurately measured.

Dimerization of Endohedral Fullerene in a Superatomic Crystal.

We describe a solid state material created from the reaction of Ni Te (PEt ) and Lu N@C . The resulting superatomic crystal, [Ni Te (PEt ) ] [(Lu N@C ) ], contains dimers of Lu N@C that form upon reduction of the fullerene through a single C-C bond at the triple hexagon junctions. The encapsulated Lu N cluster displays an unprecedented orientation that is collinear and coplanar with the intercage carbon bond.

[Autotransplantation of the internal carotid artery in patients with high localization of an atherosclerotic plaque].

Acute and chronic cerebral circulatory impairment is a very commonly encountered type of neurological diseases, annually affecting more than six million people worldwide. The absolute majority of all cases are associated with atherosclerosis of cerebral arteries. Surgical intervention in a stenotic lesion of the internal carotid artery (ICA) is a method of preventive treatment with confirmed efficacy.

Scanning Tunneling Microscopy Observation of Phonon Condensate.

Using quantum tunneling of electrons into vibrating surface atoms, phonon oscillations can be observed on the atomic scale. Phonon interference patterns with unusually large signal amplitudes have been revealed by scanning tunneling microscopy in intercalated van der Waals heterostructures. Our results show that the effective radius of these phonon quasi-bound states, the real-space distribution of phonon standing wave amplitudes, the scattering phase shifts, and the nonlinear intermode coupling strongly depend on the presence of defect-induced scattering resonance.

Microstructure dependent filament forming kinetics in HfO2 programmable metallization cells.

Variability remains the principal concern for commercialization of HfO2 based resistance switching devices. Here, we investigate the role of thermal processing conditions on internal structure of atomic layer deposited HfO2 thin films, and the impact of that structure on filament forming kinetics of p+ Si/HfO2/Cu and TiN/HfO2/Cu devices. Regardless of bias polarity or electrode metal, filament formation times are at least one order of magnitude shorter in polycrystalline than in amorphous films, which we attribute to the presence of fast ion migration along grain boundaries.

Activating "Invisible" Glue: Using Electron Beam for Enhancement of Interfacial Properties of Graphene-Metal Contact.

Interfacial contact of two-dimensional graphene with three-dimensional metal electrodes is crucial to engineering high-performance graphene-based nanodevices with superior performance. Here, we report on the development of a rapid "nanowelding" method for enhancing properties of interface to graphene buried under metal electrodes using a focused electron beam induced deposition (FEBID). High energy electron irradiation activates two-dimensional graphene structure by generation of structural defects at the interface to metal contacts with subsequent strong bonding via FEBID of an atomically thin graphitic interlayer formed by low energy secondary electron-assisted dissociation of entrapped hydrocarbon contaminants.

Approach to multifunctional device platform with epitaxial graphene on transition metal oxide.

Heterostructures consisting of two-dimensional materials have shown new physical phenomena, novel electronic and optical properties, and new device concepts not observed in bulk material systems or purely three dimensional heterostructures. These new effects originated mostly from the van der Waals interaction between the different layers. Here we report that a new optical and electronic device platform can be provided by heterostructures of 2D graphene with a metal oxide (TiO2).

Dynamic modulation of electronic properties of graphene by localized carbon doping using focused electron beam induced deposition.

We report on the first demonstration of controllable carbon doping of graphene to engineer local electronic properties of a graphene conduction channel using focused electron beam induced deposition (FEBID). Electrical measurements indicate that an "n-p-n" junction on graphene conduction channel is formed by partial carbon deposition near the source and drain metal contacts by low energy (<50 eV) secondary electrons due to inelastic collisions of long range backscattered primary electrons generated from a low dose of high energy (25 keV) electron beam (1 × 10(18) e(-) per cm(2)). Detailed AFM imaging provides direct evidence of the new mechanism responsible for dynamic evolution of the locally varying graphene doping.