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Isochoric thermal conductivity of solid thiophene is measured in “plastic” phase I, on three samples with different molar volumes at temperatures ranging from 170 K to the melting point. The thermal conductivity increased with temperature for all samples. We conducted a comparison with the isochoric thermal conductivity of other cyclic hydrocarbons in “plastic” phases. It is shown that the observed effect correlates to the changes in the magnitude of the NMR second moment in the “plastic” phases, and, respectively, with the degree of disinhibition in the rotational motion of molecules.

In the paper was indicated the essentiality of large-scale underground space development and high-rise construction of cities in Russia. The basic elements of transport facilities construction effective technology without traffic restriction are developed. Unlike the well-known solutions, it offers the inclusion of an advanced lining in the construction that strengthens the soil mass. The fundamental principles of methods for determining stress in advanced support and monitoring of underground construction, providing the application of pressure sensors, strain sensors and displacement sensors are considered.

Specific labeling of biomolecules with bright fluorophores is the keystone of fluorescence microscopy. Genetically encoded self-labeling tag proteins can be coupled to synthetic dyes inside living cells, resulting in brighter reporters than fluorescent proteins. Intracellular labeling using these techniques requires cell-permeable fluorescent ligands, however, limiting utility to a small number of classic fluorophores. Here, we describe a simple structural modification that improves the brightness and photostability of dyes while preserving spectral properties and cell permeability. Inspired by molecular modeling, we replaced the N,N-dimethylamino substituents in tetramethylrhodamine with four-membered azetidine rings. This addition of two carbon atoms doubles the quantum efficiency and improves the photon yield of the dye in applications ranging from in vitro single-molecule measurements to super-resolution imaging. The novel substitution is generalizable, yielding a palette of chemical dyes with improved quantum efficiencies that spans the UV and visible range.

The isochoric thermal conductivity of solid tetrahydrofuran C4H8O (a cyclic hydrocarbon with pseudorotational motion of molecules) was studied using samples of different density in the temperature range 120−180 K. For all the samples, the isochoric thermal conductivity was found to decrease with temperature following a much weaker dependence than 1/T. The experimental data were interpreted in terms of the Debye model of thermal conductivity considering heat transfer by both low-frequency phonons and “diffuse” modes. No significant contribution to the thermal conductivity by pseudorotation motion of the molecules was found.

The article is about modelling the process of synchronization generators on autonomous gas-turbine power plant. The paper presents the system of automatic speed control (ASC) and the synchronization algorithm for the gas turbine unit, developed in the Matlab Simulink. The proposed synchronization model makes it possible to reduce the time of input of the synchronous generator into operation.

Thermal conductivity of solid furan has been measured at isochoric conditions in the high-temperature orien-tationally-disordered phase I for samples of different densities. Our isochoric data show a gradual increase of ΛV with temperature whereas isobaric thermal conductivity goes down in this temperature range. The above effect is most clearly expressed in furan, where the atoms in the ring plane are not equivalent, as compared with earlier studied C₆H₆ and C₆H₁₂. The increase of ΛV with temperature can be attributed to weakening of the translation-al-orientational interaction which, in turn, leads to a decrease of phonon scattering on rotational excitations. The experimental data are described in terms of a modified Debye model of thermal conductivity with allowance for heat transfer by both low-frequency phonons and ―diffuse‖ modes.

The paper reports the results of testing some diagnostic video systems enabling digital rendering of TNT teeth and jaws. The authors substantiate the criteria of choosing and integration of imaging systems in future on Russian segment of the International space station kit LOR developed for examination and download of high-quality images of cosmonauts' TNT, parodentium and teeth.

Experiments on goats and rabbits showed that zinc supplement to the diet leads to calcium concentration rise in muscle, bone and blood of animals. However, this rise was not adequate to increase in.zinc consumption. The bulk of alimentary zinc stayed in soluble fraction, dense endogen fraction and infusoria fraction of digesta and stimulated calcium release from food particles, it's accumulation in digesta fractions and calcium utilization on the whole. Authors estimate animal digesta as homeostatic, spatial organized, endogenic formation in which zinc and calcium are functionally dependent through enteral mucosa.

Forty years of classical biochemical analysis have identified the molecular players involved in initiation of transcription by eukaryotic RNA polymerase II (Pol II) and largely assigned their functions. However, a dynamic picture of Pol II transcription initiation and an understanding of the mechanisms of its regulation have remained elusive due in part to inherent limitations of conventional ensemble biochemistry. Here we have begun to dissect promoter-specific transcription initiation directed by a reconstituted human Pol II system at single-molecule resolution using fluorescence video-microscopy. We detected several stochastic rounds of human Pol II transcription from individual DNA templates, observed attenuation of transcription by promoter mutations, observed enhancement of transcription by activator Sp1, and correlated the transcription signals with real-time interactions of holo-TFIID molecules at individual DNA templates. This integrated single-molecule methodology should be applicable to studying other complex biological processes.

The isochoric thermal conductivity of solid n-hexane C6H14 is studied using three samples with different densities for temperatures ranging from 100 K to the onset of melting. In all cases, the isochoric thermal conductivity varies more weakly than Λ∝1/T. The present results are compared with the thermal conductivities of other representatives of the n-alkanes. The contributions of low-frequency phonons and “diffuse modes” to the thermal conductivity are calculated.

The thermal conductivity of solid hexafluoroethane C2F6 is investigated in three samples of different density in the temperature interval from 90K up to the onset of melting. The isochroic thermal conductivity in the β phase is practically constant immediately after the α→β transition, and as the temperature is increased further it grows weakly on up to the onset of melting. This behavior is due to weakening of the translation-orientation interaction as the rotational motion of the C2F6 molecules around the C–C axis becomes less hindered.

The isochoric thermal conductivity of solid CO was investigated in three samples of different densities in the interval from 35 K to the onset of melting. In α-CO the temperature dependence of the isochoric thermal conductivity is significantly weaker than ; in β-CO it increases slightly with temperature. A quantitative description of the experimental results is given within the Debye model of thermal conductivity in the approximation of the corresponding relaxation times and which allows for the fact that the mean-free path of phonons cannot become smaller than half the phonon wavelength. On this consideration the heat is transported by both phonons and 'diffusive' modes.

The thermal conductivity of solid ethane (C2H6) is investigated for three samples of different density in the temperature range from 35K to the onset of melting. In all cases the isochoric thermal conductivity in the α and β phases decreases with increasing temperature by a dependence weaker than Λ∝1∕T. Such behavior is typical for orientationally ordered phases of molecular crystals and does not reveal any clear features due to rotation of the methyl groups. The thermal conductivities of ethane and some of its halogen derivatives (freons) are compared. The experimental results are discussed in the framework of a model in which heat is transported by low-frequency phonons, and, above the mobility edge, by high-frequency “diffusive” modes.

The isochoric thermal conductivity of Kr1−ξXeξ solid solutions (ξ=0.034, 0.072, and 0.14) is investigated in the temperature range from 80 K to Tm (Tm is the melting temperature) for samples of different densities. It is found that an increase in disordering of the crystal leads to a gradual crossover from the thermal conductivity of a perfect crystal to the lower limit of the thermal conductivity of the lattice. A quantitative description of the results obtained is performed within the Debye model of thermal conductivity and allows for the fact that the mean free path of phonons cannot be less than half the phonon wavelength.

The dependence of the thermal conductivity Λ of solid solutions of cryocrystals on the molar volume is investigated theoretically in the Callaway approach under the assumption that the heat is transferred by mobile low-frequency phonons and, above the phonon mobility edge, by “localized” modes which migrate randomly from site to site. The phonon mobility edge ω0 is found from the condition that the phonon mean free path, which is governed by umklapp processes and scattering on point defects, cannot become smaller than one-half the phonon wavelength. The Bridgman coefficient g=−(∂ ln Λ/∂ ln V)T is the weighted mean over these modes, which have strongly different volume dependences. For the example of the solid solution Kr1−c(CH4)c, where c is the mole fraction of the components, it is shown that with increasing methane concentration in krypton the Bridgman coefficient decreases, in good agreement with experiment, from g≈9, characteristic for the pure crystals, to g≈4.

Single molecule-based superresolution imaging has become an essential tool in modern cell biology. Because of the limited depth of field of optical imaging systems, one of the major challenges in superresolution imaging resides in capturing the 3D nanoscale morphology of the whole cell. Despite many previous attempts to extend the application of photo-activated localization microscopy (PALM) and stochastic optical reconstruction microscopy (STORM) techniques into three dimensions, effective localization depths do not typically exceed 1.2 µm. Thus, 3D imaging of whole cells (or even large organelles) still demands sequential acquisition at different axial positions and, therefore, suffers from the combined effects of out-of-focus molecule activation (increased background) and bleaching (loss of detections). Here, we present the use of multifocus microscopy for volumetric multicolor superresolution imaging. By simultaneously imaging nine different focal planes, the multifocus microscope instantaneously captures the distribution of single molecules (either fluorescent proteins or synthetic dyes) throughout an ∼ 4-µm-deep volume, with lateral and axial localization precisions of ∼ 20 and 50 nm, respectively. The capabilities of multifocus microscopy to rapidly image the 3D organization of intracellular structures are illustrated by superresolution imaging of the mammalian mitochondrial network and yeast microtubules during cell division.

The isochoric thermal conductivity of (CH4)1−ξKrξ solid solutions is studied between 40 K and ∼150 K over a wide range of concentrations (ξ=0.013, 0.032, 0.07, 0.115, 0.34, 0.71, 0.855, 0.937, and 0.97). A gradual transition from the thermal conductivity of a highly perfect crystal to the minimum thermal conductivity is observed as the crystal becomes increasingly more disordered. A qualitative description is given in the framework of Debye model of thermal conductivity, which takes into consideration the fact that phonon mean free path cannot decrease indefinitely.

The isochoric thermal conductivity of the solid solution Kr–CH4 with methane concentrations of 3.0 and 6.3 mol% has been studied at various densities in the temperature range 40–170 K. The additional contribution to the thermal resistance due to impurities is proportional to the impurity concentration and decreases with increasing temperature. The observed effect is explained with a simple model according to which the mean free path of high-frequency phonons is limited by the interatomic distance.

We have used systematic site-specific protein–DNA photocrosslinking to define interactions between bacterial RNA polymerase (RNAP) and promoter DNA in the catalytically competent RNAP-promoter open complex (RP o ). We have mapped more than 100 distinct crosslinks between individual segments of RNAP subunits and individual phosphates of promoter DNA. The results provide a comprehensive description of protein–DNA interactions in RP o , permit construction of a detailed model for the structure of RP o , and permit analysis of effects of a transcriptional activator on the structure of RP o .

The isochoric thermal conductivity of solid propane C3H8 is investigated on three samples of different densities in the temperature interval from 50K to the onset of melting. In all cases the isochoric thermal conductivity exhibits dependences that are weaker than Λ∝1∕T. The results obtained are compared with those for other representatives of n-alkanes. The experimental data are discussed within a model in which the heat is transported by low-frequency phonons and by “diffusive” modes above the phonon mobility edge.

The isochoric thermal conductivity of the orientationally disordered (OD) phase of solid methane has been studied at molar volumes 30.5 and 31.1 cm3/mol from 35 to 140 K. Above the order–disorder transition temperature, the isochoric thermal conductivity of methane first grows with temperature, passes through a smooth maximum and then decreases up to the melting temperature. The thermal conductivity maximum shifts towards higher temperatures as the density of the samples increases. The unusual temperature dependence of the isochoric thermal conductivity of methane is attributed to the interaction between phonons and correlated molecular rotations. The contributions of phonon–phonon scattering (Umklapp-processes) and phonon scattering at excitations of the rotational molecule motion to thermal resistance are discussed.

The body produces proteins by transcribing DNA (genes) to make messenger RNA, which is then translated to make a protein. Transcription begins when an enzyme called RNA polymerase binds to the DNA and catalyzes the process by which genetic information from the double helix is copied to a complementary RNA transcript, which subsequently becomes the messenger RNA. Because a living cell usually contains only one or a few copies (alleles) of a given gene, molecular fluctuations play a crucial role in cellular transcription. Therefore, studying transcription kinetics at the level of single molecules may provide critical insights into how cells deal with—or even take advantage of—molecular fluctuations. A number of different single-molecule techniques can be used to follow transcription, but these techniques are often relatively slow compared to transcription in living cells, or they suffer from other problems such as only being able to study one step in the transcription process. Now, Zhang, Revyakin et al. have systematically devised a technique called ‘fastFISH’ that is fast enough to track the production of single RNA molecules directly and instantaneously. FastFISH builds on an existing technique called FISH—short for fluorescence in situ hybridization—in which fluorescent molecules are attached to single strands of DNA or RNA. These single strands pair with specific regions of complementary DNA or RNA molecules, and they can be visualized with a fluorescence microscope. However, conventional FISH is a ‘snap-shot’ technique that is not suitable for making real-time observations under physiological conditions. FastFISH relies on single strands of fluorescently labeled DNA and RNA that bind to complementary strands of DNA or RNA extremely quickly, even under physiological conditions, because they contain only three of the four ‘regular’ nucleotides that make up DNA or RNA. As a proof of principle, Zhang, Revyakin et al. used fastFISH to study the kinetics of transcription by the bacteriophage T7 RNA polymerase and were able to measure multiple stages of the transcription cycle in a single-molecule experimental setup. By allowing each stage of transcription to be tracked in real-time at the level of single-molecules, fastFISH will permit a more in-depth analysis of the factors that regulate how genes are expressed as proteins in our cells. Moreover, the ability to design single-strand probes that bind rapidly to DNA and RNA targets could have many additional applications, including new strategies for more efficient gene silencing.

Enhancer-binding pluripotency regulators (Sox2 and Oct4) play a seminal role in embryonic stem (ES) cell specific gene regulation. Here, we combine in vivo and in vitro single-molecule imaging, transcription factor (TF) mutagenesis and ChIP-exo mapping to determine how TFs dynamically search for and assemble on their cognate DNA target sites. We find that enhanceosome assembly is hierarchically ordered with kinetically favored Sox2 engaging the target DNA first, followed by assisted binding of Oct4. Sox2/Oct4 follow a trial-and-error sampling mechanism involving 84~97 events of 3D diffusion (3.3~3.7s) interspersed with brief non-specific collisions (0.75~0.9s) before acquiring and dwelling at specific target DNA (12.0~14.6s). Sox2 employs a 3D diffusion-dominated (~80 % of time) search mode facilitated by 1D sliding along open DNA to efficiently seek for targets. Our findings also reveal fundamental aspects of gene and developmental regulation by fine tuning TF dynamics and influence of the epigenome on TF search parameters.