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51.
Grigory G. Borisenko Marina A. Zaitseva Andrey N. Chuvilin Galina E. Pozmogova 《Nucleic acids research》2009,37(4):e28
We report a novel approach for the attachment of DNA fragments to the surface of live cells. By using fluorescence microscopy and flow cytometry we demonstrated that our synthetic conjugates of fatty acid with oligonucleotides can be incorporated in plasma membrane and then hybridized with complementary sequences at the cell surface. Method permits to control amount of immobilized DNA on the cell surface. All procedures can be completed within minutes and do not alter cell viability. Using this approach we tethered floating myeloid HL-60 cells to adherent A431 epitheliocytes in a sequence specific fashion. Thus, this method allows rapid and simple DNA multicoding of the cell surface and, therefore, opens new opportunities in manipulating with cell–cell interactions. 相似文献
52.
Narayan P Subramaniyam Outi RM Väisänen Katrina E Wendel Jaakko AV Malmivuo 《Nonlinear biomedical physics》2010,4(Z1):S4
Background
The electroencephalography (EEG) is an attractive and a simple technique to measure the brain activity. It is attractive due its excellent temporal resolution and simple due to its non-invasiveness and sensor design. However, the spatial resolution of EEG is reduced due to the low conducting skull. In this paper, we compute the potential distribution over the closed surface covering the brain (cortex) from the EEG scalp potential. We compare two methods – L-curve and generalised cross validation (GCV) used to obtain the regularisation parameter and also investigate the feasibility in applying such techniques to N170 component of the visually evoked potential (VEP) data.Methods
Using the image data set of the visible human man (VHM), a finite difference method (FDM) model of the head was constructed. The EEG dataset (256-channel) used was the N170 component of the VEP. A forward transfer matrix relating the cortical potential to the scalp potential was obtained. Using Tikhonov regularisation, the potential distribution over the cortex was obtained.Results
The cortical potential distribution for three subjects was solved using both L-curve and GCV method. A total of 18 cortical potential distributions were obtained (3 subjects with three stimuli each – fearful face, neutral face, control objects).Conclusions
The GCV method is a more robust method compared to L-curve to find the optimal regularisation parameter. Cortical potential imaging is a reliable method to obtain the potential distribution over cortex for VEP data.53.
An original method of taxonomic identification of fish (at the family level) by means of hydroacoustic equipment is elaborated.
The method is based on analysis of the form of instantaneous envelope of amplitudes of the acoustic signal reflected from
fish. Analysis of distribution of mass fish of different size over horizons of the water column is made on the deep-water
riverbed depression of the Irtysh and characteristics of their diurnal vertical migration are revealed. 相似文献
54.
N. G. Borisenko Yu. A. Merkul’ev A. S. Orekhov S. Chaurasia S. Tripathi D. S. Munda L. J. Dhareshwar V. G. Pimenov E. E. Sheveleva 《Plasma Physics Reports》2013,39(8):668-673
The properties of microheterogeneous plasma produced by irradiation of a polymer aerogel target with an intense (1014 W/cm3) short (0.5 ps) 1.064-μm laser pulse were studied. It is found that, even at plasma densities exceeding the critical density, a small fraction of the incident laser radiation penetrates through the plasma in which the processes of density and temperature equalization still take place. The intensification (as compared to plasmas produced from denser foams and solid films) of transport processes in such plasma along and across the laser beam can be caused by the initial microheterogeneity of the solid target. The replacement of a small (10% by mass) part of the polymer with copper nanoparticles leads to a nearly twofold increase in the intensity of the plasma X-ray emission. 相似文献
55.
“Netcor” computer-aided hydroacoustic system has been used to study the pattern of spawning migration in the Shuya River of
the Atlantic salmon Salmo Salar inhabiting Onega Lake. The migrants’ length frequency and abundance have been evaluated, and the pattern of their spawning
run, as referring to observation days and the time of day, has been determined. The data obtained with the use of the hydroacoustic
system have been compared with those from a fish-counting trap at a fish-counting barrier (FCB). Hydroacoustic systems have
been shown to perform better in studies of anadromous fish migration and in the determination of migrants’ abundance and the
cycling and direction of their movements. 相似文献
56.
Doped diamond-like carbon (DLC) coatings offer potential antifouling surfaces against microbial and protein attachment. In particular, stainless steel surgical instruments are subject to tissue protein and resilient prion protein attachment, making decontamination methods used in sterile service departments ineffective, potentially increasing the risk of iatrogenic Creutzfeldt-Jakob disease during surgical procedures. This study examined the adsorption of proteins and prion-associated amyloid to doped DLC surfaces and the efficacy of commercial cleaning chemistries applied to these spiked surfaces, compared to titanium nitride coating and stainless steel. Surfaces inoculated with ME7-infected brain homogenate were visualised using SYPRO Ruby/Thioflavin T staining and modified epi-fluorescence microscopy before and after cleaning. Reduced protein and prion amyloid contamination was observed on the modified surfaces and subsequent decontamination efficacy improved. This highlights the potential for a new generation of coatings for surgical instruments to reduce the risk of iatrogenic CJD infection. 相似文献
57.
Sergey V. Borisenko Volodymyr B. Zabolotnyy Alexander A. Kordyuk Danil V. Evtushinsky Timur K. Kim Emanuela Carleschi Bryan P. Doyle Rosalba Fittipaldi Mario Cuoco Antonio Vecchione Helmut Berger 《Journal of visualized experiments : JoVE》2012,(68)
The physical properties of a material are defined by its electronic structure. Electrons in solids are characterized by energy (ω) and momentum (k) and the probability to find them in a particular state with given ω and k is described by the spectral function A(k, ω). This function can be directly measured in an experiment based on the well-known photoelectric effect, for the explanation of which Albert Einstein received the Nobel Prize back in 1921. In the photoelectric effect the light shone on a surface ejects electrons from the material. According to Einstein, energy conservation allows one to determine the energy of an electron inside the sample, provided the energy of the light photon and kinetic energy of the outgoing photoelectron are known. Momentum conservation makes it also possible to estimate k relating it to the momentum of the photoelectron by measuring the angle at which the photoelectron left the surface. The modern version of this technique is called Angle-Resolved Photoemission Spectroscopy (ARPES) and exploits both conservation laws in order to determine the electronic structure, i.e. energy and momentum of electrons inside the solid. In order to resolve the details crucial for understanding the topical problems of condensed matter physics, three quantities need to be minimized: uncertainty* in photon energy, uncertainty in kinetic energy of photoelectrons and temperature of the sample.In our approach we combine three recent achievements in the field of synchrotron radiation, surface science and cryogenics. We use synchrotron radiation with tunable photon energy contributing an uncertainty of the order of 1 meV, an electron energy analyzer which detects the kinetic energies with a precision of the order of 1 meV and a He3 cryostat which allows us to keep the temperature of the sample below 1 K. We discuss the exemplary results obtained on single crystals of Sr2RuO4 and some other materials. The electronic structure of this material can be determined with an unprecedented clarity. 相似文献
58.
Quantative estimates of abundance of anadromous Kamchatka steelhead Parasalmo mykiss in the period of its maximum spawning migration in the shallow Utkholok River by the instrumental method using Didson dual-frequency
identification sonar are presented. Equipment and methods are described for the stationary observation of spawning run of
Kamchatka steelhead through the river cross section and mobile surveys of the water area of the Utkholok R. As a result of
stationary observations, the abundance and size composition of Kamchatka steelhead migrating to the upper reaches of the river
are determined. Peculiarities of the diurnal dynamics of migration of Kamchatka steelhead characterized by two sharp peaks
of run intensity in the morning and evening were revealed. During the period of observations from September 22 to October
20, 2007, in the seasonal dynamics of migration two peaks of intensity of run of Kamchatka steelhead depending on an abrupt
decrease in water temperature by 2°C were also registered. Mobile surveys supplied data on the abundance and size composition
of Kamchatka steelhead in the surveyed water area of the river, on its spatial distribution, and dynamics of accumulation
of fish in the river. The abundance of Kamchatka steelhead in the river almost doubled every three-four days and the spatial
distribution was aggregated, producing maximum concentration mainly in areas of increasing depth and channel meandering before
and after riffles. Comparison of the results of assessment of abundance of Kamchatka steelhead that arrived for spawning in
2006 and 2007 showed significant fluctuations in population abundance. 相似文献
59.
60.
N V Tsvetkova Iu V Borisenko E M Kuznetsova L M Chudnaia E P Chaban 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》1987,(8):91-93
The sera of children and adults with a history of pertussis, as well as the sera of children immunized in three injections, have been studied in the enzyme immunoassay. The levels of antibodies to Bordetella pertussis protein and lipopolysaccharide, and to disintegrated B. pertussis cells have been determined; a serum titer of 1:1,600 and higher is considered as a criterion for the serological diagnosis of pertussis. 相似文献