Multimodal nonlinear microscopy combining third-harmonic generation (THG) with two- and three-photon-excited fluorescence (2PEF and 3PEF) is shown to provide a powerful resource for high-fidelity ...imaging of nucleoli and nucleolar proteins. We demonstrate that, with a suitably tailored genetically encoded fluorescent stain, the 2PEF/3PEF readout from specific nucleolar proteins can be reliably detected against the extranucleolar 2PEF/3PEF signal, enabling high-contrast imaging of the key nucleolar ribosome biogenesis components, such as fibrillarin. THG is shown to provide a versatile readout for unstained nucleolus imaging in a vast class of biological systems as different as neurons in brain slices and cultured HeLa cells.
Nowadays droplet microfluidics is widely used to perform high throughput assays and for the synthesis of micro- and nanoparticles. These applications usually require packaging several reagents into ...droplets and their mixing to start a biochemical reaction. For rapid mixing microfluidic devices usually require additional functional elements that make their designs more complex. Here we perform a series of 2D numerical simulations, followed by experimental studies, and introduce a novel asymmetric flow-focusing droplet generator, which enhances mixing during droplet formation due to a 2D or 3D asymmetric vortex, located in the droplet formation area of the microfluidic device. Our results suggest that 2D numerical simulations can be used for qualitative analysis of two-phase flows and droplet generation process in quasi-two-dimensional devices, while the relative simplicity of such simulations allows them to be easily applied to fairly complicated microfluidic geometries. Mixing inside droplets formed in the asymmetric generator occurs up to six times faster than in a conventional symmetric one. The best mixing efficiency is achieved in a specific range of droplet volumes, which can be changed by scaling the geometry of the device. Thus, the droplet generator suggested here can significantly simplify designs of microfluidic devices because it enables both the droplet formation and fast mixing of the reagents within droplets. Moreover, it can be used to precisely estimate reaction kinetics.
Thermal activation of transient receptor potential (TRP) cation channels is one of the most striking examples of temperature-controlled processes in cell biology. As the evidence indicating the ...fundamental role of such processes in thermosensation builds at a fast pace, adequately accurate tools that would allow heat receptor logic behind thermosensation to be examined on a single-cell level are in great demand. Here, we demonstrate a specifically designed fiber-optic probe that enables thermal activation with simultaneous online thermometry of individual cells expressing genetically encoded TRP channels. This probe integrates a fiber-optic tract for the delivery of laser light with a two-wire microwave transmission line. A diamond microcrystal fixed on the fiber tip is heated by laser radiation transmitted through the fiber, providing a local heating of a cell culture, enabling a well-controlled TRP-assisted thermal activation of cells. Online local temperature measurements are performed by using the temperature-dependent frequency shift of optically detected magnetic resonance, induced by coupling the microwave field, delivered by the microwave transmission line, to nitrogen--vacancy centers in the diamond microcrystal. Activation of TRP channels is verified by using genetically encoded fluorescence indicators, visualizing an increase in the calcium flow through activated TRP channels.
Optically detected electron spin resonance in fiber-coupled nitrogen-vacancy (NV) centers of diamond is used to demonstrate a fiber-optic quantum thermometry of individual thermogenetically activated ...neurons. Laser-induced temperature variations read out from single neurons with the NV-diamond fiber sensor are shown to strongly correlate with the fluorescence of calcium-ion sensors, serving as online indicators of the inward Ca
current across the cell membrane of neurons expressing transient receptor potential (TRP) cation channels. Local laser heating above the TRP-channel activation threshold is shown to reproducibly evoke robust action potentials, visualized by calcium-ion-sensor-aided fluorescence imaging and detected as prominent characteristic waveforms in the time-resolved response of fluorescence Ca
sensors.
Main parameters of the possible system of electron cyclotron resonance heating of the plasma for the compact tokamak with strong magnetic field (TRT) are presented. Preliminary estimates show that, ...to deposit radiation with calculated power of 10 MW into the plasma at pulse duration of 100 s, 12 1-MW gyrotron complexes will be required that operate at a frequency of 230 GHz. Preliminary calculations of the main components of the system are presented.
We designed a genetically encoded ratiometric fluorescent probe, SypHer3s, with enhanced brightness and optimized pK
, which responds to pH changes in different cellular compartments. SypHer3s was ...successfully utilized for imaging the pH dynamics in mitochondria of living neurons and in quantitative pH measurement in zebrafish embryos.
Substances of silver nanoparticles dialyzed through a 13 kDa membrane, synthesized in a medium of humic ligands modified with hydroquinone and 2-hydroxynaphthoquinone from PowHumus brown coal, ...specifically enhance the M2 properties of peritoneal macrophages due to inhibition of NO synthase and significant activation of arginase, thus enhancing anti-inflammatory properties of cells. In small, but effective concentrations, they do not have cytotoxic properties and do not contain pyrogenic impurities. The studied humates are able to influence the mechanisms of immune response formation and are an effective means for correcting inflammation and regeneration.
The results of a combined description of data on the differential and total scattering cross sections and the
-parameter for
collisions in tuning the parameters of an analytic model constructed in ...order to describe data over a broad region of kinematical variables for
GeV and all currently available experimental data on
are presented. The experimental data were taken from the COMPAS group (IHEP) compilations and the CLM compilations and were supplemented with data from the FNAL-COLLIDER-D0 and CERN-LHC-TOTEM experiments and with cosmic-ray data from the Pierre Auger Observatory (PAO).
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