81 research outputs found
Engineering of Papaya Mosaic Virus (PapMV) Nanoparticles through Fusion of the HA11 Peptide to Several Putative Surface-Exposed Sites
Papaya mosaic virus has been shown to be an efficient adjuvant and vaccine platform in the design and improvement of innovative flu vaccines. So far, all fusions based on the PapMV platform have been located at the C-terminus of the PapMV coat protein. Considering that some epitopes might interfere with the self-assembly of PapMV CP when fused at the C-terminus, we evaluated other possible sites of fusion using the influenza HA11 peptide antigen. Two out of the six new fusion sites tested led to the production of recombinant proteins capable of self assembly into PapMV nanoparticles; the two functional sites are located after amino acids 12 and 187. Immunoprecipitation of each of the successful fusions demonstrated that the HA11 epitope was located at the surface of the nanoparticles. The stability and immunogenicity of the PapMV-HA11 nanoparticles were evaluated, and we could show that there is a direct correlation between the stability of the nanoparticles at 37Β°C (mammalian body temperature) and the ability of the nanoparticles to trigger an efficient immune response directed towards the HA11 epitope. This strong correlation between nanoparticle stability and immunogenicity in animals suggests that the stability of any nanoparticle harbouring the fusion of a new peptide should be an important criterion in the design of a new vaccine
Mode decomposition of Kerr self-cleaned beams by phase only SLM
Graded-index multimode optical bers have recently attracted a renewed attention, thanks to the discovery
of new nonlinear eects, such as Kerr beam self-cleaning. In essence, Kerr self-cleaning involves a
ow of
the propagating beam energy into the fundamental mode of the ber, accompanied by a redistribution of the
remaining energy among high-order modes. Increasing the fundamental mode energy leads to a signicant
improvement of the output beam quality. A standard method to determine beam quality is to measure the M2
parameter. However, since self-cleaning involves the nonlinear redistribution of energy among a large number of
ber modes, measuring a single beam quality parameter is not sucient to characterize the eect. A properly
informative approach requires performing the mode decomposition of the output beam. Mode decomposition
permits to evaluate the energy distribution among all of the excited ber modes, which enables investigations
of nonlinear mode coupling processes at a qualitatively new level. In this work, we demonstrate an eciency
mode decomposition method based on holography, which is suitable for analyzing the self-cleaning eect. In
a theoretical study, we describe the solution of the mode decomposition problem for the modes of the gradedindex
multimode ber. In an experimental investigation, we demonstrate the decomposition of both low-power
(speckled) and self-cleaned beams, involving more than 80 modes
Multicolour nonlinearly bound chirped dissipative solitons
The dissipative soliton regime is one of the most advanced ways to generate high-energy femtosecond pulses in mode-locked lasers. On the other hand, the stimulated Raman scattering in a fibre laser may convert the excess energy out of the coherent dissipative soliton to a noisy Raman pulse, thus limiting its energy. Here we demonstrate that intracavity feedback provided by re-injection of a Raman pulse into the laser cavity leads to formation of a coherent Raman dissipative soliton. Together, a dissipative soliton and a Raman dissipative soliton (of the first and second orders) form a two (three)-colour stable complex with higher total energy and broader spectrum than those of the dissipative soliton alone. Numerous applications can benefit from this approach, including frequency comb spectroscopy, transmission lines, seeding femtosecond parametric amplifiers, enhancement cavities and multiphoton fluorescence microscopy
Π ΠΠ‘Π¨ΠΠ ΠΠΠΠ ΠΠΠΠΠΠΠ§ΠΠ‘ΠΠΠΠ ΠΠΠΠΠΠΠΠΠ ΠΠΠΠΠΠΠΠ’ΠΠ ΠΠ ΠΠΠΠ‘ ΠΠ ΠΠ‘ΠΠΠΠ ΠΠΠΠΠΠ Π€ΠΠ’ΠΠΠΠ’ΠΠΠ’ΠΠ ΠΠ ΠΠΠΠ-2000 Π ΠΠΠΠ-4000
One trend in the development of integral atomic emission spectral analysis with low spectral background excitation sources, such as inductively coupled or microwave plasma, is to increase the dynamic range of spectrum recording systems based on photodetector arrays. To achieve low detection limits, it is necessary to use photodetector arrays with low reading noise. The dynamic range of a single readout of such photodetector arrays usually does not exceed four orders of magnitude. The dynamic range increase due to the accumulation of spectra from multiple acquisition leads to a quadratic increase in the measurement time. This method does not allow one to cover the entire dynamic range of spectral line intensities of inductively coupled or microwave plasma (which can reach seven orders of magnitude) while maintaining an acceptable total measurement time of a sample spectrum. As an alternative, it is proposed to increase the dynamic range toward higher line intensities by using two different alternating accumulation times during measurement. The objective of this study is to implement the proposed recording mode in MAES analyzers based on BLPP-2000 and BLPP-4000 photodetector arrays in order to increase the dynamic range of recorded spectral lines. Dependences of the signal-to-noise ratio and the dynamic range of spectral lines recorded in integral atomic emission spectrometry on the accumulation time, the total measurement time, the spectral background level, and the photodetector array parameters are obtained. It is shown theoretically that the use of the recording mode with alternating different accumulation times should increase the dynamic range of BLPP-2000 and BLPP-4000 photodetector arrays by two orders of magnitude. The dynamic range of spectral line intensities of a hollow-cathode lamp is shown experimentally to increase by two orders of magnitude (to five orders of magnitude).Keywords: atomic emission spectrometry, inductively coupled plasma, microwave plasma, spectrum analyzer, MAES, photodetector arrays, extended dynamic range, alternating exposureΒ DOI: http://dx.doi.org/10.15826/analitika.2021.25.4.011Sergey A. Babin1,2, Vladimir A. Labusov1,2,3, Denis O. Selyunin1,2, and OlegΒ V.Β Pelipasov1,21Institute of Automation and Electrometry, Siberian Branch of the Russian Academy of Sciences, pr. Akademika Koptyuga, 1, Novosibirsk, 630090, Russian Federation2VMK-Optoelektronika, pr. Akademika Koptyuga, 1, Novosibirsk, 630090,Russian Federation3Novosibirsk State Technical University, pr. K. Marksa, 20, Novosibirsk,630073, Russian FederationΠΠ΄Π½ΠΎ ΠΈΠ· Π½Π°ΠΏΡΠ°Π²Π»Π΅Π½ΠΈΠΉ ΡΠ°Π·Π²ΠΈΡΠΈΡ ΠΌΠ΅ΡΠΎΠ΄Π° Π°ΡΠΎΠΌΠ½ΠΎ-ΡΠΌΠΈΡΡΠΈΠΎΠ½Π½ΠΎΠ³ΠΎ ΡΠΏΠ΅ΠΊΡΡΠ°Π»ΡΠ½ΠΎΠ³ΠΎ Π°Π½Π°Π»ΠΈΠ·Π° Ρ ΠΈΡΡΠΎΡΠ½ΠΈΠΊΠ°ΠΌΠΈ Π²ΠΎΠ·Π±ΡΠΆΠ΄Π΅Π½ΠΈΡ ΡΠΏΠ΅ΠΊΡΡΠΎΠ², ΠΈΠΌΠ΅ΡΡΠΈΠΌΠΈ Π½ΠΈΠ·ΠΊΡΡ ΠΈΠ½ΡΠ΅Π½ΡΠΈΠ²Π½ΠΎΡΡΡ ΡΡΠΎΠ²Π½Ρ ΡΠΏΠ΅ΠΊΡΡΠ°Π»ΡΠ½ΠΎΠ³ΠΎ ΡΠΎΠ½Π°, ΡΠ°ΠΊΠΈΡ
ΠΊΠ°ΠΊ ΠΈΠ½Π΄ΡΠΊΡΠΈΠ²Π½ΠΎ ΡΠ²ΡΠ·Π°Π½Π½Π°Ρ ΠΈΠ»ΠΈ ΠΌΠΈΠΊΡΠΎΠ²ΠΎΠ»Π½ΠΎΠ²Π°Ρ ΠΏΠ»Π°Π·ΠΌΠ°, ΡΠ²Π»ΡΠ΅ΡΡΡ ΡΠ²Π΅Π»ΠΈΡΠ΅Π½ΠΈΠ΅ Π΄ΠΈΠ½Π°ΠΌΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ Π΄ΠΈΠ°ΠΏΠ°Π·ΠΎΠ½Π° ΡΠΈΡΡΠ΅ΠΌ ΡΠ΅Π³ΠΈΡΡΡΠ°ΡΠΈΠΈ ΡΠΏΠ΅ΠΊΡΡΠΎΠ² Π½Π° ΠΎΡΠ½ΠΎΠ²Π΅ Π»ΠΈΠ½Π΅Π΅ΠΊ ΡΠΎΡΠΎΠ΄Π΅ΡΠ΅ΠΊΡΠΎΡΠΎΠ². ΠΠ»Ρ Π΄ΠΎΡΡΠΈΠΆΠ΅Π½ΠΈΡ Π½ΠΈΠ·ΠΊΠΈΡ
ΠΏΡΠ΅Π΄Π΅Π»ΠΎΠ² ΠΎΠ±Π½Π°ΡΡΠΆΠ΅Π½ΠΈΡ Π½Π΅ΠΎΠ±Ρ
ΠΎΠ΄ΠΈΠΌΠΎ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°ΡΡ Π»ΠΈΠ½Π΅ΠΉΠΊΠΈ Ρ ΠΌΠ°Π»ΡΠΌ Π·Π½Π°ΡΠ΅Π½ΠΈΠ΅ΠΌ Π‘ΠΠ ΡΡΠΌΠ° ΡΡΠ΅Π½ΠΈΡ. ΠΠΈΠ½Π°ΠΌΠΈΡΠ΅ΡΠΊΠΈΠΉ Π΄ΠΈΠ°ΠΏΠ°Π·ΠΎΠ½ ΠΎΠ΄ΠΈΠ½ΠΎΡΠ½ΠΎΠ³ΠΎ ΡΡΠ΅Π½ΠΈΡ ΡΠ°ΠΊΠΈΡ
Π»ΠΈΠ½Π΅Π΅ΠΊ ΡΠΎΡΠΎΠ΄Π΅ΡΠ΅ΠΊΡΠΎΡΠΎΠ² ΠΎΠ±ΡΡΠ½ΠΎ Π½Π΅ ΠΏΡΠ΅Π²ΡΡΠ°Π΅Ρ ΡΠ΅ΡΡΡΠ΅Ρ
ΠΏΠΎΡΡΠ΄ΠΊΠΎΠ². Π£Π²Π΅Π»ΠΈΡΠ΅Π½ΠΈΠ΅ Π΄ΠΈΠ½Π°ΠΌΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ Π΄ΠΈΠ°ΠΏΠ°Π·ΠΎΠ½Π° Π·Π° ΡΡΠ΅Ρ ΠΌΠ½ΠΎΠ³ΠΎΠΊΡΠ°ΡΠ½ΠΎΠΉ ΡΠ΅Π³ΠΈΡΡΡΠ°ΡΠΈΠΈ ΠΈ Π½Π°ΠΊΠΎΠΏΠ»Π΅Π½ΠΈΡ ΡΠΏΠ΅ΠΊΡΡΠΎΠ² ΠΏΡΠΈΠ²ΠΎΠ΄ΠΈΡ ΠΊ ΠΊΠ²Π°Π΄ΡΠ°ΡΠΈΡΠ½ΠΎΠΌΡ ΡΠΎΡΡΡ Π²ΡΠ΅ΠΌΠ΅Π½ΠΈ ΠΈΠ·ΠΌΠ΅ΡΠ΅Π½ΠΈΡ. Π’Π°ΠΊΠΎΠΉ ΡΠΏΠΎΡΠΎΠ± Π½Π΅ ΠΏΠΎΠ·Π²ΠΎΠ»ΡΠ΅Ρ ΠΏΠ΅ΡΠ΅ΠΊΡΡΡΡ Π²Π΅ΡΡ Π΄ΠΈΠ½Π°ΠΌΠΈΡΠ΅ΡΠΊΠΈΠΉ Π΄ΠΈΠ°ΠΏΠ°Π·ΠΎΠ½ ΠΈΠ½ΡΠ΅Π½ΡΠΈΠ²Π½ΠΎΡΡΠ΅ΠΉ ΡΠΏΠ΅ΠΊΡΡΠ°Π»ΡΠ½ΡΡ
Π»ΠΈΠ½ΠΈΠΉ ΠΈΠ½Π΄ΡΠΊΡΠΈΠ²Π½ΠΎ ΡΠ²ΡΠ·Π°Π½Π½ΠΎΠΉ ΠΈ ΠΌΠΈΠΊΡΠΎΠ²ΠΎΠ»Π½ΠΎΠ²ΠΎΠΉ ΠΏΠ»Π°Π·ΠΌΡ, ΠΊΠΎΡΠΎΡΡΠΉ ΠΌΠΎΠΆΠ΅Ρ Π΄ΠΎΡΡΠΈΠ³Π°ΡΡ 7 ΠΏΠΎΡΡΠ΄ΠΊΠΎΠ², ΠΏΡΠΈ ΡΠΎΡ
ΡΠ°Π½Π΅Π½ΠΈΠΈ ΠΏΡΠΈΠ΅ΠΌΠ»Π΅ΠΌΠΎΠ³ΠΎ ΠΏΠΎΠ»Π½ΠΎΠ³ΠΎ Π²ΡΠ΅ΠΌΠ΅Π½ΠΈ ΡΠ΅Π³ΠΈΡΡΡΠ°ΡΠΈΠΈ ΡΠΏΠ΅ΠΊΡΡΠ° ΠΎΠ±ΡΠ°Π·ΡΠ°. Π ΠΊΠ°ΡΠ΅ΡΡΠ²Π΅ Π°Π»ΡΡΠ΅ΡΠ½Π°ΡΠΈΠ²Ρ ΠΏΡΠ΅Π΄Π»ΠΎΠΆΠ΅Π½ΠΎ ΡΠ²Π΅Π»ΠΈΡΠ΅Π½ΠΈΠ΅ Π΄ΠΈΠ½Π°ΠΌΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ Π΄ΠΈΠ°ΠΏΠ°Π·ΠΎΠ½Π° Π² ΡΡΠΎΡΠΎΠ½Ρ ΡΠ΅Π³ΠΈΡΡΡΠ°ΡΠΈΠΈ Π±α½ΉΠ»ΡΡΠΈΡ
ΠΈΠ½ΡΠ΅Π½ΡΠΈΠ²Π½ΠΎΡΡΠ΅ΠΉ Π»ΠΈΠ½ΠΈΠΉ Π·Π° ΡΡΡΡ ΡΠ΅Π³ΠΈΡΡΡΠ°ΡΠΈΠΈ ΡΠΏΠ΅ΠΊΡΡΠΎΠ² Π² ΡΠ΅ΡΠ΅Π½ΠΈΠ΅ Π²ΡΠ΅ΠΌΠ΅Π½ΠΈ ΠΈΠ·ΠΌΠ΅ΡΠ΅Π½ΠΈΡ Ρ ΠΏΠΎΠΏΠ΅ΡΠ΅ΠΌΠ΅Π½Π½ΡΠΌ ΡΠ΅ΡΠ΅Π΄ΠΎΠ²Π°Π½ΠΈΠ΅ΠΌ Π½Π°ΠΊΠΎΠΏΠ»Π΅Π½ΠΈΠΉ Π΄Π²ΡΡ
ΡΠ°Π·Π»ΠΈΡΠ½ΡΡ
ΠΏΡΠΎΠ΄ΠΎΠ»ΠΆΠΈΡΠ΅Π»ΡΠ½ΠΎΡΡΠ΅ΠΉ. Π¦Π΅Π»Ρ ΡΠ°Π±ΠΎΡΡ β Π²Π½Π΅Π΄ΡΠ΅Π½ΠΈΠ΅ ΠΏΡΠ΅Π΄Π»ΠΎΠΆΠ΅Π½Π½ΠΎΠ³ΠΎ ΡΠ΅ΠΆΠΈΠΌΠ° Π² Π°Π½Π°Π»ΠΈΠ·Π°ΡΠΎΡΡ ΠΠΠΠ‘ Ρ Π»ΠΈΠ½Π΅ΠΉΠΊΠ°ΠΌΠΈ ΡΠΎΡΠΎΠ΄Π΅ΡΠ΅ΠΊΡΠΎΡΠΎΠ² ΠΠΠΠβ2000 ΠΈ ΠΠΠΠβ4000 Π΄Π»Ρ ΡΠ²Π΅Π»ΠΈΡΠ΅Π½ΠΈΡ Π΄ΠΈΠ½Π°ΠΌΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ Π΄ΠΈΠ°ΠΏΠ°Π·ΠΎΠ½Π° ΡΠ΅Π³ΠΈΡΡΡΠΈΡΡΠ΅ΠΌΡΡ
ΡΠΏΠ΅ΠΊΡΡΠ°Π»ΡΠ½ΡΡ
Π»ΠΈΠ½ΠΈΠΉ. Π ΡΠ°Π±ΠΎΡΠ΅ ΠΏΠΎΠ»ΡΡΠ΅Π½Ρ ΡΠΎΡΠΌΡΠ»Ρ Π·Π°Π²ΠΈΡΠΈΠΌΠΎΡΡΠΈ ΠΎΡΠ½ΠΎΡΠ΅Π½ΠΈΡ ΡΠΈΠ³Π½Π°Π»-ΡΡΠΌ ΠΈ Π΄ΠΈΠ½Π°ΠΌΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ Π΄ΠΈΠ°ΠΏΠ°Π·ΠΎΠ½Π° ΡΠ΅Π³ΠΈΡΡΡΠ°ΡΠΈΠΈ ΡΠΏΠ΅ΠΊΡΡΠ°Π»ΡΠ½ΡΡ
Π»ΠΈΠ½ΠΈΠΉ Π² ΠΈΠ½ΡΠ΅Π³ΡΠ°Π»ΡΠ½ΠΎΠΉ Π°ΡΠΎΠΌΠ½ΠΎ-ΡΠΌΠΈΡΡΠΈΠΎΠ½Π½ΠΎΠΉ ΡΠΏΠ΅ΠΊΡΡΠΎΠΌΠ΅ΡΡΠΈΠΈ Π² Π·Π°Π²ΠΈΡΠΈΠΌΠΎΡΡΠΈ ΠΎΡ ΠΏΡΠΎΠ΄ΠΎΠ»ΠΆΠΈΡΠ΅Π»ΡΠ½ΠΎΡΡΠΈ Π½Π°ΠΊΠΎΠΏΠ»Π΅Π½ΠΈΡ, ΠΏΠΎΠ»Π½ΠΎΠ³ΠΎ Π²ΡΠ΅ΠΌΠ΅Π½ΠΈ ΠΈΠ·ΠΌΠ΅ΡΠ΅Π½ΠΈΡ, ΡΡΠΎΠ²Π½Ρ ΡΠΏΠ΅ΠΊΡΡΠ°Π»ΡΠ½ΠΎΠ³ΠΎ ΡΠΎΠ½Π° ΠΈ ΠΏΠ°ΡΠ°ΠΌΠ΅ΡΡΠΎΠ² Π»ΠΈΠ½Π΅Π΅ΠΊ. Π’Π΅ΠΎΡΠ΅ΡΠΈΡΠ΅ΡΠΊΠΈ ΠΏΠΎΠΊΠ°Π·Π°Π½ΠΎ, ΡΡΠΎ ΠΏΡΠΈΠΌΠ΅Π½Π΅Π½ΠΈΠ΅ ΡΠ΅ΠΆΠΈΠΌΠ° ΡΠ΅Π³ΠΈΡΡΡΠ°ΡΠΈΠΈ Ρ ΡΠ΅ΡΠ΅Π΄ΠΎΠ²Π°Π½ΠΈΠ΅ΠΌ Π½Π°ΠΊΠΎΠΏΠ»Π΅Π½ΠΈΠΉ ΡΠ°Π·Π»ΠΈΡΠ½ΠΎΠΉ ΠΏΡΠΎΠ΄ΠΎΠ»ΠΆΠΈΡΠ΅Π»ΡΠ½ΠΎΡΡΠΈ Π΄ΠΎΠ»ΠΆΠ½ΠΎ ΡΠ²Π΅Π»ΠΈΡΠΈΡΡ Π΄ΠΈΠ½Π°ΠΌΠΈΡΠ΅ΡΠΊΠΈΠΉ Π΄ΠΈΠ°ΠΏΠ°Π·ΠΎΠ½ ΠΈΠ·ΠΌΠ΅ΡΠ΅Π½ΠΈΡ Π»ΠΈΠ½Π΅Π΅ΠΊ ΡΠΎΡΠΎΠ΄Π΅ΡΠ΅ΠΊΡΠΎΡΠΎΠ² ΠΠΠΠβ2000 ΠΈ ΠΠΠΠβ4000 Π½Π° Π΄Π²Π° ΠΏΠΎΡΡΠ΄ΠΊΠ°. ΠΠΊΡΠΏΠ΅ΡΠΈΠΌΠ΅Π½ΡΠ°Π»ΡΠ½ΠΎ ΠΏΠΎΠΊΠ°Π·Π°Π½ΠΎ ΡΠ²Π΅Π»ΠΈΡΠ΅Π½ΠΈΠ΅ Π΄ΠΈΠ½Π°ΠΌΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ Π΄ΠΈΠ°ΠΏΠ°Π·ΠΎΠ½Π° ΠΈΠ·ΠΌΠ΅ΡΠ΅Π½ΠΈΡ ΠΈΠ½ΡΠ΅Π½ΡΠΈΠ²Π½ΠΎΡΡΠΈ ΡΠΏΠ΅ΠΊΡΡΠ°Π»ΡΠ½ΡΡ
Π»ΠΈΠ½ΠΈΠΉ Π»Π°ΠΌΠΏΡ ΠΏΠΎΠ»ΠΎΠ³ΠΎ ΠΊΠ°ΡΠΎΠ΄Π° Π½Π° Π΄Π²Π° ΠΏΠΎΡΡΠ΄ΠΊΠ° Π΄ΠΎ 5 ΠΏΠΎΡΡΠ΄ΠΊΠΎΠ² Π²Π΅Π»ΠΈΡΠΈΠ½Ρ.ΠΠ»ΡΡΠ΅Π²ΡΠ΅ ΡΠ»ΠΎΠ²Π°: Π°ΡΠΎΠΌΠ½ΠΎ-ΡΠΌΠΈΡΡΠΈΠΎΠ½Π½Π°Ρ ΡΠΏΠ΅ΠΊΡΡΠΎΠΌΠ΅ΡΡΠΈΡ, ΠΈΠ½Π΄ΡΠΊΡΠΈΠ²Π½ΠΎ-ΡΠ²ΡΠ·Π°Π½Π½Π°Ρ ΠΏΠ»Π°Π·ΠΌΠ°, ΠΌΠΈΠΊΡΠΎΠ²ΠΎΠ»Π½ΠΎΠ²Π°Ρ ΠΏΠ»Π°Π·ΠΌΠ°, Π°Π½Π°Π»ΠΈΠ·Π°ΡΠΎΡ ΡΠΏΠ΅ΠΊΡΡΠΎΠ², ΠΠΠΠ‘, Π»ΠΈΠ½Π΅ΠΉΠΊΠΈ ΡΠΎΡΠΎΠ΄Π΅ΡΠ΅ΠΊΡΠΎΡΠΎΠ², ΡΠ°ΡΡΠΈΡΠ΅Π½Π½ΡΠΉ Π΄ΠΈΠ½Π°ΠΌΠΈΡΠ΅ΡΠΊΠΈΠΉ Π΄ΠΈΠ°ΠΏΠ°Π·ΠΎΠ½, ΡΠ΅ΡΠ΅Π΄ΠΎΠ²Π°Π½ΠΈΠ΅ Π²ΡΠ΅ΠΌΡΠ½ ΡΠΊΡΠΏΠΎΠ·ΠΈΡΠΈΠΉDOI: http://dx.doi.org/10.15826/analitika.2021.25.4.01
All-fiber highly chirped dissipative soliton generation in the telecom range
A high-energy (0.93 nJ) all-fiber erbium femtosecond oscillator operating in the telecom spectral range is proposed and realized. The laser cavity, built of commercially available fibers and components, combines polarization maintaining (PM) and non-PM parts providing stable generation of highly chirped (chirp parameter 40) pulses compressed in an output piece of standard PM fiber to 165 fs. The results of the numerical simulation agree well with the experiment. The analyzed intracavity pulse dynamics enables the classification of the generated pulses as dissipative solitons
Experimental Method of Temperature and Strain Discrimination in Polymer Composite Material by Embedded Fiber-Optic Sensors Based on Femtosecond-Inscribed FBGs
Experimental method of temperature and strain discrimination with fiber Bragg gratings (FBGs) sensors embedded in carbon fiber-reinforced plastic is proposed. The method is based on two-fiber technique, when two FBGs inscribed in different fibers with different sensitivities to strain and/or temperature are placed close to each other and act as a single sensing element. The nonlinear polynomial approximation of Bragg wavelength shift as a function of temperature and strain is presented for this method. The FBGs were inscribed with femtosecond laser by point-by-point inscription technique through polymer cladding of the fiber. The comparison of linear and nonlinear approximation accuracies for array of embedded sensors is performed. It is shown that the use of nonlinear approximation gives 1.5β2 times better accuracy. The obtained accuracies of temperature and strain measurements are 2.6β3.8Β°C and 50β83βΞΌΞ΅ in temperature and strain range of 30β120Β°C and 0β400βΞΌΞ΅, respectively
High affinity binding of pyrethroids to the οΏ½ subunit of brain sodium channels
SUMMARY Na Ο© channels are the primary molecular targets of the pyrethroid insecticides. Na Ο© channels consisting of only a type IIA β£ subunit expressed in Chinese hamster ovary cells responded to pyrethroid treatment in a normal manner: a sustained Na Ο© current was induced progressively after each depolarizing pulse in a train of stimuli, and this Na Ο© current decayed slowly on repolarization. These modified Na Ο© channels could be reactivated at much more negative membrane potentials (V 0.5 Ο Οͺ139 mV) than unmodified Na Ο© channels (V 0.5 Ο Οͺ28 mV). These results indicate that pyrethroids can modify the functional properties of the Na Ο© channel β£ subunit expressed alone by blocking their inactivation, shifting their voltage dependence of activation, and slowing their deactivation. To demonstrate directly the specific interaction of pyrethroids with the β£ subunit of voltage-gated Na Ο© channels, a radioactive photosensitive derivative, [ 3 H]RU58487, was used in binding and photolabeling studies. In the presence of a low concentration of the nonionic detergent Triton X-100, specific pyrethroid binding to Na Ο© channels in rat brain membrane preparations could be measured and reached 75% of total binding under optimal conditions. Binding approached equilibrium within 1 hr at 4Β°, dissociated with a half-time of Ο³10 min, and had K D values of Ο³58 -300 nM for three representative pyrethroids. Specific pyrethroid binding was enhanced by Ο³40% in the presence of 100 nM β£-scorpion toxin, but no allosteric enhancement was observed in the presence of toxins acting at other Na Ο© channel receptor sites. Extensive membrane washing increased specific binding to 89%. Photolabeling with [ 3 H]RU58487 under these optimal binding conditions revealed a radiolabeled band with an apparent molecular mass of 240 kDa corresponding to the Na Ο© channel β£ subunit. Anti-peptide antibodies recognizing sequences within the β£ subunit were able to specifically immunoprecipitate the covalently modified channel. Together, these results demonstrate that the pyrethroids can modify the properties of cells expressing only the β£ subunit of Na Ο© channels and can bind specifically to a receptor site on the β£ subunit
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