The influence of salt concentration on the dissolution of microbubbles in bulk aqueous electrolyte solutions.

We study microbubbles (MBs) in aqueous electrolyte solutions and show that increasing the salt concentration slows down the kinetics of MB dissolution. We modified the Epstein-Plesset theory and experimented with NaCl aqueous solutions to estimate the MB effective surface charge and to compare it with predictions from the modified Poisson-Boltzmann theory. Our results reveal a mechanism responsible for the change in the dissolution of MBs in aqueous electrolyte solutions, with implications for emerging fields ranging from physics of solutions to soft and biological matter.

Feasibility of Monitoring Tissue Properties During Microcirculation Disorder Using a Compact Fiber-Based Probe With Sapphire Tip.

One of the urgent tasks of modern medicine is to detect microcirculation disorder during surgery to avoid possible consequences like tissue hypoxia, ischemia, and necrosis. To address this issue, in this article, we propose a compact probe with sapphire tip and optical sensing based on the principle of spatially resolved diffuse reflectance analysis. It allows for intraoperative measurement of tissue effective attenuation coefficient and its alteration during the changes of tissue condition, caused by microcirculation disorder.

Lifshitz Transition in a Single-Atom-Thick GdYbPb Kagome Compound on Si(111).

Lanthanide (Ln) elements Gd and Yb alloyed with a Pb monolayer on the Si(111) substrate form LnPb compounds having the same crystal structure. They comprise a single-atom-thick Pb layer arranged in a slightly distorted kagome lattice with Ln atoms filling the hexagonal voids. They have similar electronic band structures except for the Fermi level position, which varies between the divalent Yb- and trivalent Gd-containing compounds by ∼0.

Optical Sensing of Tissue Freezing Depth by Sapphire Cryo-Applicator and Steady-State Diffuse Reflectance Analysis.

This work describes a sapphire cryo-applicator with the ability to sense tissue freezing depth during cryosurgery by illumination of tissue and analyzing diffuse optical signals in a steady-state regime. The applicator was manufactured by the crystal growth technique and has several spatially resolved internal channels for accommodating optical fibers. The method of reconstructing freezing depth proposed in this work requires one illumination and two detection channels.

Novel Technique for Box-Lesion Ablation of Atrial Fibrillation Combined with Off-Pump Coronary Surgery.

Introduction: We propose a new technique for box-lesion ablation combined with off-pump coronary artery bypass grafting for the treatment of patients with coronary artery disease and paroxysmal or persistent atrial fibrillation.

Methods: Eight male patients with paroxysmal (n=2) or persistent atrial fibrillation (n=6) and coronary artery disease underwent box-lesion ablation combined with off-pump coronary artery bypass grafting. Box-lesion ablation was performed using a bipolar flexible clamping device with irrigated electrodes which was originally designed for thoracoscopic epicardial ablation.

Feasibility test of a sapphire cryoprobe with optical monitoring of tissue freezing.

This article describes a sapphire cryoprobe as a promising solution to the significant problem of modern cryosurgery that is the monitoring of tissue freezing. This probe consists of a sapphire rod manufactured by the edge-defined film-fed growth technique from Al O melt and optical fibers accommodated inside the rod and connected to the source and the detector. The probe's design enables detection of spatially resolved diffuse reflected intensities of tissue optical response, which are used for the estimation of tissue freezing depth.

Novel Genes Involved in Hypertrophic Cardiomyopathy: Data of Transcriptome and Methylome Profiling.

Hypertrophic cardiomyopathy (HCM) is the most common inherited heart disease; its pathogenesis is still being intensively studied to explain the reasons for the significant genetic and phenotypic heterogeneity of the disease. To search for new genes involved in HCM development, we analyzed gene expression profiles coupled with DNA methylation profiles in the hypertrophied myocardia of HCM patients. The transcriptome analysis identified significant differences in the levels of 193 genes, most of which were underexpressed in HCM.

Gold Interlayer Promotes Superconductivity in Single and Double Atomic Pb Layers on Si(100).

Introducing an atomic Au monolayer between a Pb film and a Si(100) substrate allows us to fabricate Pb films with single- and double-atom thicknesses. The Pb films have a 2D square-lattice structure with the 1D atomic chains of Pb adatoms on their top, forming Si(100)1 × 7-(Pb, Au) and Si(100)5 × 1-(Pb, Au) superstructures for single and double atomic Pb layers, respectively. Their common characteristic feature is the occurrence of bundles of quasi-1D metallic bands.

A 2D heavy fermion CePb kagome material on silicon: emergence of unique spin polarized states for spintronics.

We report on the successful synthesis of a 2D atomically thin heavy-fermion CePb kagome compound on a Si(111) surface. Growth and morphology were controlled and characterized through scanning tunneling microscopy observations revealing the high crystalline quality of the sample. Angle-resolved photoelectron spectroscopy measurements revealed the giant highly-anisotropic Rashba-like spin splitting of the surface states and semi-metallic character of the spectrum.

Soft-Magnetic Skyrmions Induced by Surface-State Coupling in an Intrinsic Ferromagnetic Topological Insulator Sandwich Structure.

A magnetic skyrmion induced on a ferromagnetic topological insulator (TI) is a real-space manifestation of the chiral spin texture in the momentum space and can be a carrier for information processing by manipulating it in tailored structures. Here, a sandwich structure containing two layers of a self-assembled ferromagnetic septuple-layer TI, Mn(BiSb)Te (MnBST), separated by quintuple layers of TI, (BiSb)Te (BST), is fabricated and skyrmions are observed through the topological Hall effect in an intrinsic magnetic topological insulator for the first time. The thickness of BST spacer layer is crucial in controlling the coupling between the gapped topological surface states in the two MnBST layers to stabilize the skyrmion formation.

Proof of concept for the sapphire scalpel combining tissue dissection and optical diagnosis.

Objectives: The development of compact diagnostic probes and instruments with an ability to direct access to organs and tissues and integration of these instruments into surgical workflows is an important task of modern physics and medicine. The need for such tools is essential for surgical oncology, where intraoperative visualization and demarcation of tumor margins define further prognosis and survival of patients. In this paper, the possible solution for this intraoperative imaging problem is proposed and its feasibility to detect tumorous tissue is studied experimentally.

Metal Sheet of Atomic Thickness Embedded in Silicon.

The controlled confinement of the metallic delta-layer to a single atomic plane has so far remained an unsolved problem. In the present study, the delta-type structure with atomic sheet of NiSi silicide embedded into a crystalline Si matrix has been fabricated using room-temperature overgrowth of a Si film onto the Tl/NiSi/Si(111) atomic sandwich in ultrahigh vacuum. Tl atoms segregate at the growing Si film surface, and the 1.

Solving a Long-Standing Problem Regarding Atomic Structure of Si(100)2×3-Ag.

The atomic structure of the Si(100)2×3-Ag reconstruction has remained unknown for more than 25 years since its first observation with scanning tunneling microscopy, despite a relatively small unit cell and seeming abundance of the available experimental data. We propose a structural model of the Si(100)3×2-Ag reconstruction which comfortably fits all the principal experimental findings, including our own and those reported in the literature. The model incorporates 3 Si atoms and 4 Ag atoms per the 2 × 3 unit cell forming linear atomic chains along the 3-periodic direction.

Engineering of Numerous Moiré Superlattices in Twisted Multilayer Graphene for Twistronics and Straintronics Applications.

Because of their unique atomic structure, 2 materials are able to create an up-to-date paradigm in fundamental science and technology on the way to engineering the band structure and electronic properties of materials on the nanoscale. One of the simplest methods along this path is the superposition of several 2 nanomaterials while simultaneously specifying the twist angle between adjacent layers (θ), which leads to the emergence of Moiré superlattices. The key challenge in 2 nanoelectronics is to obtain a nanomaterial with numerous Moiré superlattices in addition to a high carrier mobility in a stable and easy-to-fabricate material.

Niche partitioning of bacterial communities along the stratified water column in the Black Sea.

The Black Sea is the largest semi-closed permanently anoxic basin on our planet with long-term stratification. The study aimed at describing the Black Sea microbial community taxonomic and functional composition within the range of depths spanning across oxic/anoxic interface, and to uncover the factors behind both their vertical and regional differentiation. 16S rRNA gene MiSeq sequencing was applied to get the data on microbial community taxonomy, and the PICRUSt pipeline was used to infer their functional profile.

Structural and electronic properties of C fullerene network self-assembled on metal-covered semiconductor surfaces.

Using first-principles density functional theory calculations, we made an accurate structural characterization of the C superstructures self-assembled on the Tl-adsorbed Si(111) and Ge(111) surfaces, which finds a good agreement with the recent scanning tunneling microscopy observations. Our band structure calculations revealed the semi-metallic character of the C/Tl/Si(111) system, while the C/Tl/Ge(111) system was found to show up the pronounced metallic character due to the cascade of the flat bands lying in the vicinity of the Fermi level. The latter is a fingerprint for strong correlation effects in the C/Tl/Ge(111) system, which makes it a promising object for studying electrical transport phenomena and opens the prospects for its application in the molecular-based electronic devices.

In situ terahertz monitoring of an ice ball formation during tissue cryosurgery: a feasibility test.

Significance: Uncontrolled cryoablation of tissues is a strong reason limiting the wide application of cryosurgery and cryotherapy due to the certain risks of unpredicted damaging of healthy tissues. The existing guiding techniques are unable to be applied in situ or provide insufficient spatial resolution. Terahertz (THz) pulsed spectroscopy (TPS) based on sensitivity of THz time-domain signal to changes of tissue properties caused by freezing could form the basis of an instrument for observation of the ice ball formation.

Simultaneous Thoracoscopic Approach in a Patient with Long-Standing Persistent Atrial Fibrillation and Primary Lung Cancer: the First Described Case.

Cardiac rhythm disorders are common in many patients with cancer. The management of synchronous long-standing persistent atrial fibrillation and pulmonary lesions remains a serious surgical dilemma due to the lack of clinical data and surgical guidelines. To the best of our knowledge, this is the first described case of simultaneous thoracoscopic pulmonary segmentectomy and left atrial posterior wall and pulmonary vein isolation combined with left atrial appendage resection in a patient with early-stage primary lung cancer and long-standing persistent atrial fibrillation.

Microfocusing sapphire capillary needle for laser surgery and therapy: Fabrication and characterization.

A sapphire shaped capillary needle designed for collimating and focusing of laser radiation was proposed and fabricated by the edge-defined film-fed growth technique. It features an as-grown surface quality, high transparency for visible and near-infrared radiation, high thermal and chemical resistance and the complex shape of the tip, which protects silica fibers. The needle's geometrical parameters can be adjusted for use in various situations, such as type of tissue, modality of therapy and treatment protocol.

Masseter-to-Facial Cranial Nerve Anastomosis: A Report of 30 Cases.

Background: Facial nerve paralysis (FP) is a possible complication of cerebellopontine angle tumor surgery. Several donor nerves have been used in the past for facial reanimation. We report the results of 30 cases of masseter-to-facial anastomosis.

Thoracoscopic Pulmonary Vein and Left Atrial Posterior Wall Isolation Combined with Left Atrial Appendage Resection in Patients with Long-Standing Persistent Atrial Fibrillation.

Objective: To evaluate the efficacy and safety of a modified technique for totally thoracoscopic left atrial posterior wall and pulmonary vein isolation in patients with long-standing persistent atrial fibrillation.

Methods: From April 2017 to December 2018, we included in this study 28 consecutive patients who underwent thoracoscopic left atrial posterior wall and pulmonary vein radiofrequency isolation combined with left atrial appendage resection. We used a device with irrigated electrodes (Medtronic Cardioblate Gemini-s).

Trivial band topology of ultra-thin rhombohedral SbSe grown on BiSe.

Thin films of rhombohedral SbSe with thicknesses from 1 to 5 quintuple layers (QL) were grown on BiSe/Si(1 1 1) substrate. The electronic band structure of the grown films and the SbSe/BiSe interface were studied using angle-resolved photoemission spectroscopy. It was found that while SbSe has an electronic band structure generally similar to that of BiSe, there is no fingerprints of band inversion in it.

Surgical treatment of atrial fibrillation: technique of thoracoscopic radiofrequency fragmentation of the left atrium.

Presented in the article is a detailed description of a modified technique of minimally invasive surgical treatment of patients with atrial fibrillation - thoracoscopic radiofrequency fragmentation of the left atrium. This modification differs from the prototype GALAXY procedure by a significant increase of the 'quantitative' rather than 'qualitative' parameter of surgical aggression in relation to the left atrium. This technique results in creation of multiple transmural continuous closed lines of lesion to the left atrium and, consequently, a reduced risk of inadequate surgical treatment for atrial fibrillation.