Role of phosphate-coordinating arginine residues in the thermal stability of uridine phosphorylase from Shewanella oneidensis MR-1.

The role of phosphate-coordinating arginine residues in the thermal stability of uridine phosphorylase from Shewanella oneidensis MR-1 was investigated by mutation analysis. Uridine phosphorylase mutant genes were constructed by site-directed mutagenesis. The enzyme mutants were prepared and isolated, and their kinetic parameters were determined.

Laser-Induced µ-Rooms for Osteocytes on Implant Surface: An In Vivo Study.

Laser processing of dental implant surfaces is becoming a more widespread replacement for classical techniques due to its undeniable advantages, including control of oxide formation and structure and surface relief at the microscale. Thus, using a laser, we created several biomimetic topographies of various shapes on the surface of titanium screw-shaped implants to research their success and survival rates. A distinctive feature of the topographies is the presence of "µ-rooms", which are special spaces created by the depressions and elevations and are analogous to the µ-sized room in which the osteocyte will potentially live.

Fluorescence-based thermometry for precise estimation of nanoparticle laser-induced heating in cancerous cells at nanoscale.

Photothermal therapy (PTT) has attracted increasing interest as a complementary method to be used alongside conventional therapies. Despite a great number of studies in this field, only a few have explored how temperatures affect the outcome of the PTT at nanoscale. In this work, we study the necrosis/apoptosis process of cancerous cells that occurs during PTT, using a combination of local laser heating and nanoscale fluorescence thermometry techniques.

Vanadate as a new substrate for nucleoside phosphorylases.

Orthovanadate was shown to serve as a substrate for nucleoside phosphorylases from Escherichia coli, Shewanella oneidensis, Geobacillus stearothermophilus, and Halomonas chromatireducens AGD 8-3. An exception is thymidine phosphorylase from the extremophilic haloalkaliphilic bacterium Halomonas chromatireducens AGD 8-3, which cannot catalyze the vanadolysis of nucleosides. The kinetic parameters of nucleoside vanadolysis were evaluated.

Elementary autonomous surface microfluidic devices based on laser-fabricated wetting gradient microtextures that drive directional water flows.

Topography-dependent tuning of water wettability was achieved on a stainless steel surface textured by nanosecond-laser pulses at different laser fluences, with the minimal contribution of the surface chemical modification. Such differently-wet neighboring surface spots were demonstrated to drive an autonomous directional water flow. A series of elementary microfluidic devices based on the spatial wetting gradients were designed and tested as building blocks of "green", energy-saving autonomous microfluidic circuits.

Optical Sensitivity of Waveguides Inscribed in Nanoporous Silicate Framework.

Laser direct writing technique in glass is a powerful tool for various waveguides' fabrication that highly develop the element base for designing photonic devices. We apply this technique to fabricate waveguides in porous glass (PG). Nanoporous optical materials for the inscription can elevate the sensing ability of such waveguides to higher standards.

Laser Thermochemical High-Contrast Recording on Thin Metal Films.

Laser-induced thermochemical recording of nano- and microsized structures on thin films has attracted intense interest over the last few decades due to essential applications in the photonics industry. Nevertheless, the relationship between the laser parameters and the properties of the formed oxide structures, both geometrical and optical, is still implicit. In this work, direct laser interference patterning of the titanium (Ti) film in the oxidative regime was applied to form submicron periodical structures.

Fluorescent Bulk Waveguide Sensor in Porous Glass: Concept, Fabrication, and Testing.

In this work, we suggest the new concept of sensing elements-bulk waveguides (BWGs) fabricated by the laser direct writing technique inside porous glass (PG). BWGs in nanoporous materials are promising to be applied in the photonics and sensors industries. Such light-guiding components interrogate the internal conditions of nanoporous materials and are able to detect chemical or physical reactions occurring inside nanopores especially with small molecules, which represent a separate class for sensing technologies.

Formation of the Submicron Oxidative LIPSS on Thin Titanium Films During Nanosecond Laser Recording.

Laser-induced periodic surface structures (LIPSSs) spontaneously appearing on the laser-treated (melted or evaporated) surfaces of bulk solid materials seem to be a well-studied phenomenon. Peculiarities of oxidative mechanisms of LIPSS formation on thin films though are far less clear. In this work, the appearance of oxidative LIPSSs on thin titanium films was demonstrated under the action of commercially available nanosecond-pulsed Yb-fiber laser.

Nondestructive Femtosecond Laser Lithography of Ni Nanocavities by Controlled Thermo-Mechanical Spallation at the Nanoscale.

We present a new approach to femtosecond direct laser writing lithography to pattern nanocavities in ferromagnetic thin films. To demonstrate the concept, we irradiated 300 nm thin nickel films by single intense femtosecond laser pulses through glass substrate. Using a fluence above the ablation threshold, the process is destructive, leading to the formation of an ablation crater.

Numerical Investigation of Ultrashort Laser-Ablative Synthesis of Metal Nanoparticles in Liquids Using the Atomistic-Continuum Model.

We present a framework based on the atomistic continuum model, combining the Molecular Dynamics (MD) and Two Temperature Model (TTM) approaches, to characterize the growth of metal nanoparticles (NPs) under ultrashort laser ablation from a solid target in water ambient. The model is capable of addressing the kinetics of fast non-equilibrium laser-induced phase transition processes at atomic resolution, while in continuum it accounts for the effect of free carriers, playing a determinant role during short laser pulse interaction processes with metals. The results of our simulations clarify possible mechanisms, which can be responsible for the observed experimental data, including the presence of two populations of NPs, having a small (5-15 nm) and larger (tens of nm) mean size.

Extracellular DNA Containing (dG)n Motifs Penetrates into MCF7 Breast Cancer Cells, Induces the Adaptive Response, and Can Be Expressed.

Background: Oxidized human DNA or plasmid DNAs containing human ribosomal genes can easily penetrate into the breast cancer cells MCF7 and stimulate the adaptive response induction. Plasmid DNA containing a CMV promoter, gene , and the insertion of the human ribosomal genes can be expressed. A hypothesis is proposed: these features of the ribosomal DNA are due to the presence of dGn motifs that are prone to oxidize.

All-optical, self-focused laser beam array for parallel laser surface processing.

A single femtosecond laser beam can be focused to process material surfaces. However, the low processing efficiency by a single laser beam prevents broad applications of femtosecond laser surface processing. Here we have demonstrated an array of high-intensity femtosecond laser beams that self-focus in a piece of glass medium, enabling high-efficiency, millimeter scale parallel laser surface processing.

Oxidized Cell-Free DNA Role in the Antioxidant Defense Mechanisms under Stress.

The present study focuses on the investigation of the oxidized cell-free DNA (cfDNA) properties in several experimental models, including cultured cerebellum cells, peripheral blood lymphocytes (PBL), plasma, and hippocampus under an acute and chronic unpredictable stress model in rats. Firstly, our study shows that Spectrum Green fluorescence-labeled oxidized cfDNA fragments were transferred into the cytoplasm of 80% of the cerebellum culture cells; meanwhile, the nonoxidized cfDNA fragments do not pass into the cells. Oxidized cfDNA stimulates the antioxidant mechanisms and induction of transcription factor NRF2 expression, followed by an activation of NRF2 signaling pathway genes-rise of and gene expression and consequently NRF2 protein synthesis.

Ribosomal DNA as DAMPs Signal for MCF7 Cancer Cells.

The cell free ribosomal DNA (cf-rDNA) is accrued in the total pool of cell free DNA (cfDNA) in some non-cancer diseases and demonstrates DAMPs characteristics. The major research questions: (1) How does cell free rDNA content change in breast cancer; (2) What type of response in the MCF7 breast cancer cells is caused by cf-rDNA; and (3) What type of DNA sensors (TLR9 or AIM2) is stimulated in MCF7 in response to the action of cf-rDNA? CfDNA and gDNA were isolated from the blood plasma and the cells derived from 38 breast cancer patients and 20 healthy female controls. The rDNA content in DNA was determined using non-radioactive quantitative hybridization.

Increased Transfection of the Easily Oxidizable GC-Rich DNA Fragments into the MCF7 Breast Cancer Cell.

Objective: Easily oxidizable GC-rich DNA (GC-DNA) fragments accumulate in the cell-free DNA (cfDNA) of patients with various diseases. The human oxidized DNA penetrates the MCF7 breast cancer cells and significantly changes their physiology. It can be assumed that readily oxidizable GC-DNA fragments can penetrate the cancer cells and be expressed.

Nanosecond-Laser Generation of Nanoparticles in Liquids: From Ablation through Bubble Dynamics to Nanoparticle Yield.

A comprehensive picture of the nanosecond-laser generation of colloidal nanoparticles in liquids is nowadays the demand of their high-throughput industrial fabrication for diverse perspective biomedical, material science, and optoelectronic applications. In this study, using silicon as an example, we present a self-consistent experimental visualization and theoretical description of key transient stages during nanosecond-laser generation of colloidal nanoparticles in liquids: plasma-mediated injection of ablated mass into the liquid and driving the vapor bubble, finalized by the colloid appearance in the liquid. The explored fundamental transient stages envision the basic temporal and spatial scales, as well as laser parameter windows, for the demanded high-throughput nanosecond-laser generation of colloidal nanoparticles in liquids.

High-resolution large-scale plasmonic laser color printing for jewelry applications.

We offer to use optical features of surface plasmon resonance in Ag nanoparticles for jewelry application as a method for the well-controlled decoration of silver items. The novel approach of silver nanoparticles formation with sizes from 5 to 50 nm via nanosecond direct laser writing allows for controlling the reflectance spectra, thus creating a color image on precious metals with a high resolution of about 450 dpi without dyes or hazardous chemicals. Moreover, the large-scale color image can be applied in single-step processing with significant productivity of 2 cm per minute.

Direct laser writing of barriers with controllable permeability in porous glass.

Barriers were produced in porous glass through its local bulk density modification by direct femtosecond writing accompanied by СО-laser surface thermal densification, to make functional microfluidic elements separated by such physical barriers with different controlled permeability. The separation of multi-component solutions into individual components with different molecule sizes (molecular separation) was performed in this first integrated microfluidic device fabricated in porous glass. Its application in the environmental gas-phase analysis was demonstrated.

From an increase in the number of tandem repeats through the decrease of sialylation to the downregulation of MUC1 expression level.

Enhanced glucose uptake by cancer cells was demonstrated in many studies in vitro and in vivo. Glycolysis is one of the main ways of obtaining energy in hypoxia conditions. However, in addition to energy exchange, carbohydrates are also necessary for the posttranslational modification of the protein molecules.

Changes of and /NF-B Expression Levels Induced by Cell-Free DNA in Different Cell Types.

Cell-free DNA (cfDNA) is a circulating DNA of nuclear and mitochondrial origin mainly derived from dying cells. Recent studies have shown that cfDNA is a stress signaling DAMP (damage-associated molecular pattern) molecule. We report here that the expression profiles of cfDNA-induced factors NRF2 and NF-B are distinct depending on the target cell's type and the GC-content and oxidation rate of the cfDNA.

Controlled nanostructures formation on stainless steel by short laser pulses for products protection against falsification.

The coloration of stainless steel surface due to the formation of spatially periodic structures induced by laser pulses of nanosecond duration is demonstrated. The period of microstructures corresponds to the laser wavelength, and their orientation angle depends on the adjustment of laser polarization. The marking algorithm for the development of authentication patterns is presented.

Low-Dose Ionizing Radiation Affects Mesenchymal Stem Cells via Extracellular Oxidized Cell-Free DNA: A Possible Mediator of Bystander Effect and Adaptive Response.

We have hypothesized that the adaptive response to low doses of ionizing radiation (IR) is mediated by oxidized cell-free DNA (cfDNA) fragments. Here, we summarize our experimental evidence for this model. Studies involving measurements of ROS, expression of the NOX (superoxide radical production), induction of apoptosis and DNA double-strand breaks, antiapoptotic gene expression and cell cycle inhibition confirm this hypothesis.

Dual Role of the Extracellular Domain of Human Mucin MUC1 in Metastasis.

Human mucin MUC1 plays an important role in cancer development. The increased level of this molecule expression during cancer cell progression induces metastasis and is associated with poor prognosis for patients. There is a large body of experimental data on the role of various functional domains of human mucin MUC1 in metastasis.

Double nanosecond pulses generation in ytterbium fiber laser.

Double pulse generation mode for nanosecond ytterbium fiber laser was developed. Two sequential 60-200 ns laser pulses with variable delay between them were generated by acousto-optic modulator opening with continuous diode pumping. A custom radio frequency generator was developed to produce two sequential "opening" radio pulses with a delay of 0.