1
|
Gudkov SV, Gao M, Simakin AV, Baryshev AS, Pobedonostsev RV, Baimler IV, Rebezov MB, Sarimov RM, Astashev ME, Dikovskaya AO, Molkova EA, Kozlov VA, Bunkin NF, Sevostyanov MA, Kolmakov AG, Kaplan MA, Sharapov MG, Ivanov VE, Bruskov VI, Kalinichenko VP, Aiyyzhy KO, Voronov VV, Pimpha N, Li R, Shafeev GA. Laser Ablation-Generated Crystalline Selenium Nanoparticles Prevent Damage of DNA and Proteins Induced by Reactive Oxygen Species and Protect Mice against Injuries Caused by Radiation-Induced Oxidative Stress. Materials (Basel) 2023; 16:5164. [PMID: 37512437 PMCID: PMC10386620 DOI: 10.3390/ma16145164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Revised: 06/25/2023] [Accepted: 07/17/2023] [Indexed: 07/30/2023]
Abstract
With the help of laser ablation, a technology for obtaining nanosized crystalline selenium particles (SeNPs) has been created. The SeNPs do not exhibit significant toxic properties, in contrast to molecular selenium compounds. The administration of SeNPs can significantly increase the viabilities of SH-SY5Y and PCMF cells after radiation exposure. The introduction of such nanoparticles into the animal body protects proteins and DNA from radiation-induced damage. The number of chromosomal breaks and oxidized proteins decreases in irradiated mice treated with SeNPs. Using hematological tests, it was found that a decrease in radiation-induced leukopenia and thrombocytopenia is observed when selenium nanoparticles are injected into mice before exposure to ionizing radiation. The administration of SeNPs to animals 5 h before radiation exposure in sublethal and lethal doses significantly increases their survival rate. The modification dose factor for animal survival was 1.2. It has been shown that the introduction of selenium nanoparticles significantly normalizes gene expression in the cells of the red bone marrow of mice after exposure to ionizing radiation. Thus, it has been demonstrated that SeNPs are a new gene-protective and radioprotective agent that can significantly reduce the harmful effects of ionizing radiation.
Collapse
Affiliation(s)
- Sergey V Gudkov
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilova St., 119991 Moscow, Russia
- Russian Scientific-Research Institute of Phytopathology of Russian Academy of Sciences, 143050 Big Vyazemy, Russia
- Institute of Biology and Biomedicine, Lobachevsky State University of Nizhny Novgorod, 603022 Nizhny Novgorod, Russia
| | - Meng Gao
- State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou Medical College, Soochow University, Suzhou 215123, China
| | - Alexander V Simakin
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilova St., 119991 Moscow, Russia
| | - Alexey S Baryshev
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilova St., 119991 Moscow, Russia
| | - Roman V Pobedonostsev
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilova St., 119991 Moscow, Russia
| | - Ilya V Baimler
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilova St., 119991 Moscow, Russia
| | - Maksim B Rebezov
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilova St., 119991 Moscow, Russia
| | - Ruslan M Sarimov
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilova St., 119991 Moscow, Russia
| | - Maxim E Astashev
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilova St., 119991 Moscow, Russia
- Institute of Cell Biophysics of the Russian Academy of Sciences, Federal Research Center "Push-chino Scientific Center for Biological Research of the Russian Academy of Sciences", Institutskaya St., 3, 142290 Pushchino, Russia
| | - Anastasia O Dikovskaya
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilova St., 119991 Moscow, Russia
| | - Elena A Molkova
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilova St., 119991 Moscow, Russia
| | - Valery A Kozlov
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilova St., 119991 Moscow, Russia
- Department of Fundamental Sciences, Bauman Moscow State Technical University, 2-nd Baumanskaya Str. 5, 105005 Moscow, Russia
| | - Nikolay F Bunkin
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilova St., 119991 Moscow, Russia
- Department of Fundamental Sciences, Bauman Moscow State Technical University, 2-nd Baumanskaya Str. 5, 105005 Moscow, Russia
| | - Mikhail A Sevostyanov
- Russian Scientific-Research Institute of Phytopathology of Russian Academy of Sciences, 143050 Big Vyazemy, Russia
- A. A. Baikov Institute of Metallurgy and Materials Science (IMET RAS) of the Russian Academy of Sciences, Leninsky Prospect, 49, 119334 Moscow, Russia
| | - Alexey G Kolmakov
- A. A. Baikov Institute of Metallurgy and Materials Science (IMET RAS) of the Russian Academy of Sciences, Leninsky Prospect, 49, 119334 Moscow, Russia
| | - Mikhail A Kaplan
- A. A. Baikov Institute of Metallurgy and Materials Science (IMET RAS) of the Russian Academy of Sciences, Leninsky Prospect, 49, 119334 Moscow, Russia
| | - Mars G Sharapov
- Institute of Cell Biophysics of the Russian Academy of Sciences, Federal Research Center "Push-chino Scientific Center for Biological Research of the Russian Academy of Sciences", Institutskaya St., 3, 142290 Pushchino, Russia
| | - Vladimir E Ivanov
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilova St., 119991 Moscow, Russia
- Institute of Theoretical and Experimental Biophysics of the Russian Academy of Sciences, Institutskaya St. 3, 142290 Pushchino, Russia
| | - Vadim I Bruskov
- Institute of Theoretical and Experimental Biophysics of the Russian Academy of Sciences, Institutskaya St. 3, 142290 Pushchino, Russia
| | - Valery P Kalinichenko
- Russian Scientific-Research Institute of Phytopathology of Russian Academy of Sciences, 143050 Big Vyazemy, Russia
- Institute of Fertility of Soils of South Russia, 346493 Persianovka, Russia
| | - Kuder O Aiyyzhy
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilova St., 119991 Moscow, Russia
| | - Valery V Voronov
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilova St., 119991 Moscow, Russia
| | - Nuttaporn Pimpha
- National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA) 111, Phahonyotin Rd, Klong Luang 12120, Thailand
| | - Ruibin Li
- State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou Medical College, Soochow University, Suzhou 215123, China
| | - Georgy A Shafeev
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilova St., 119991 Moscow, Russia
| |
Collapse
|
2
|
Gudkov SV, Simakin AV, Bunkin NF, Shafeev GA, Astashev ME, Glinushkin AP, Grinberg MA, Vodeneev VA. Development and application of photoconversion fluoropolymer films for greenhouses located at high or polar latitudes. J Photochem Photobiol B 2020; 213:112056. [PMID: 33142218 DOI: 10.1016/j.jphotobiol.2020.112056] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 09/25/2020] [Accepted: 10/13/2020] [Indexed: 11/28/2022]
Abstract
To convert and store energy in the process of photosynthesis, plants primarily use quanta of the red and blue parts of the spectrum. At high latitudes, the average daily intensity of red and blue parts of the spectrum is not very high; for many crops cultivated under greenhouse conditions, it reaches the sufficient level only on clear summer days. The problem of insufficient illumination in greenhouses is usually solved with artificial light sources. This article describes a technology for the manufacture of photoconversion fluoropolymer films for greenhouses. The fluoropolymer films described in the paper make use of original gold nanoparticles and nanoparticles with fluorescence in the blue or red region of the spectrum. In the polymer film, nanoparticles aggregate in the form of "beads", which enhances the field of the optical wave. The film photoconverts UV and violet light into blue and red light. Gold nanoparticles also partially convert energy in the green region of the spectrum (not used by plants) into heat, which is also important for agriculture at high latitudes. In addition, impregnation of gold nanoparticles into fluoropolymer significantly increases the lifetime of the film. The films described in the paper can significantly increase the productivity of greenhouses located at high latitudes. Plants cultivated under the films have more chlorophyll and a higher intensity of photosynthesis - although their system of distance stress signals is, to a certain degree, suppressed.
Collapse
Affiliation(s)
- Sergey V Gudkov
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilova St, Moscow 119991, Russia.
| | - Alexander V Simakin
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilova St, Moscow 119991, Russia
| | - Nikolay F Bunkin
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilova St, Moscow 119991, Russia; Bauman Moscow State Technical University, 2-nd Baumanskaya str. 5, Moscow 105005, Russia
| | - Georgy A Shafeev
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilova St, Moscow 119991, Russia
| | - Maxim E Astashev
- Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilova St, Moscow 119991, Russia; Institute of Cell Biophysics of the Russian Academy of Sciences, 3 Institutskaya St., Pushchino, Moscow 119991, Russia
| | - Alexey P Glinushkin
- All-Russian Research Institute of Phytopatology, ul. Institut 5, Bolshie Vyazemy, Moscow 143050, Russia
| | - Marina A Grinberg
- Institute of Biology and Biomedicine, Lobachevsky State University of Nizhny Novgorod, 23 Gagarin Ave, Nizhny Novgorod 603950, Russia
| | - Vladimir A Vodeneev
- Institute of Biology and Biomedicine, Lobachevsky State University of Nizhny Novgorod, 23 Gagarin Ave, Nizhny Novgorod 603950, Russia
| |
Collapse
|
3
|
Abstract
The swelling of a polymer ion-exchange membrane Nafion in water with various heavy isotope contents (D2O) was studied by photoluminescent UV spectroscopy. The photoluminescence arises because of the presence of sulfonic groups attached to the ends of the perfluorovinyl ether groups that form the tetrafluoroethylene (Teflon) backbone of Nafion. The width of the colloidal region, which is formed near the membrane surface as a result of the outgrowth of Nafion microfibers toward the bulk liquid, varies non-monotonically with D2O content, displaying a narrow maximum in the low concentration region. A significant insight into the unexpected isotopic effects revealed in swelling Nafion in deuterated water is provided. Mainly, the polymer swelling is very sensitive to small changes (on the order of several tens of parts per million) in the content of deuterium, which, for instance, can help in understanding the isotopic effects in living tissues.
Collapse
Affiliation(s)
- N F Bunkin
- Bauman Moscow State Technical University, Second Baumanskaya Str. 5, Moscow 105005, Russia
| | - A V Shkirin
- Prokhorov General Physics Institute of the Russian Academy of Sciences, Vavilova Str. 38, Moscow 119991, Russia
| | - V A Kozlov
- Bauman Moscow State Technical University, Second Baumanskaya Str. 5, Moscow 105005, Russia
| | - B W Ninham
- The Australian National University, Acton, ACT 2601, Australia
| | - E V Uspenskaya
- RUDN University, Miklukho-Maklaya Str. 6, Moscow 117198, Russia
| | - S V Gudkov
- Prokhorov General Physics Institute of the Russian Academy of Sciences, Vavilova Str. 38, Moscow 119991, Russia
| |
Collapse
|
4
|
Bunkin NF, Shkirin AV, Lyakhov GA, Kobelev AV, Penkov NV, Ugraitskaya SV, Fesenko EE. Droplet-like heterogeneity of aqueous tetrahydrofuran solutions at the submicrometer scale. J Chem Phys 2017; 145:184501. [PMID: 27846700 DOI: 10.1063/1.4966187] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A droplet formation in aqueous solutions of tetrahydrofuran (THF) has been experimentally detected at the submicrometer scale using two independent laser diagnostic techniques (dynamic light scattering and laser phase microscopy) and described in terms of THF-water intermolecular hydrogen bonding. It is shown that the nanodroplets have a mean size of 300 nm, their refractive index is higher than that of the ambient liquid, and they are highly enriched with THF molecules. The maximum of light scattering intensity falls within the THF concentration range 2-8 mol. %, which corresponds to the volume number density of the nanodroplets ∼1010-1011 cm-3. A theoretical explanation of forming the nanodroplets with a high content of THF, which is based on a model of dichotomous noise being applied to the so-termed "twinkling" hydrogen bonds and involves spinodal decomposition in the unstable region enclosed within the dichotomous binodal, is proposed. The parameters of hydrogen bonds in the molecular system "water-THF" were found, and the phase diagram of the solution with allowance for cross-linking hydrogen bonds was constructed.
Collapse
Affiliation(s)
- N F Bunkin
- Bauman State Technical University, 2nd Baumanskaya ul. 5, Moscow 105005, Russia
| | - A V Shkirin
- Prokhorov General Physics Institute, Russian Academy of Sciences, ul. Vavilova 38, Moscow 119991, Russia
| | - G A Lyakhov
- Prokhorov General Physics Institute, Russian Academy of Sciences, ul. Vavilova 38, Moscow 119991, Russia
| | - A V Kobelev
- Institute of Cell Biophysics, Russian Academy of Sciences, ul. Institutskaya 3, Pushchino, Moscow Region 142290, Russia
| | - N V Penkov
- Institute of Cell Biophysics, Russian Academy of Sciences, ul. Institutskaya 3, Pushchino, Moscow Region 142290, Russia
| | - S V Ugraitskaya
- Institute of Cell Biophysics, Russian Academy of Sciences, ul. Institutskaya 3, Pushchino, Moscow Region 142290, Russia
| | - E E Fesenko
- Institute of Cell Biophysics, Russian Academy of Sciences, ul. Institutskaya 3, Pushchino, Moscow Region 142290, Russia
| |
Collapse
|
5
|
Affiliation(s)
- Nikolay F. Bunkin
- A.M. Prokhorov General Physics Institute, Moscow, Vavilova 38, 119991 Russia
- Bauman Moscow State Technical University, Moscow, Second Baumanskaya, 5, 105005 Russia
- Institute of Cell Biophysics, Pushchino, Moscow Region, Institutskaya
3, 142290 Russia
| | - Vladimir S. Gorelik
- P.N. Lebedev Physical Institute, Moscow, Leninskiy prospekt 53, 119991 Russia
- Bauman Moscow State Technical University, Moscow, Second Baumanskaya, 5, 105005 Russia
| | - Valeriy A. Kozlov
- A.M. Prokhorov General Physics Institute, Moscow, Vavilova 38, 119991 Russia
| | - Alexey V. Shkirin
- A.M. Prokhorov General Physics Institute, Moscow, Vavilova 38, 119991 Russia
| | - Nikolay V. Suyazov
- A.M. Prokhorov General Physics Institute, Moscow, Vavilova 38, 119991 Russia
| |
Collapse
|
6
|
Bunkin NF, Shkirin AV. Nanobubble clusters of dissolved gas in aqueous solutions of electrolyte. II. Theoretical interpretation. J Chem Phys 2012; 137:054707. [PMID: 22894371 DOI: 10.1063/1.4739530] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
A quantitative model of ion-stabilized gas bubbles is suggested. Charging the bubbles by the ions, which are capable of adsorption, and the screening by a cloud of counter-ions, which are less absorptable, is modeled. It is shown that, subject to the charge of bubble, two regimes of such screening can be realized. For low-charged bubbles, the screening is described in the framework of the known linearized Debye-Huckel approach, when the sign of the counter-ion cloud is preserved everywhere in the liquid, whereas at large charge this sign is changed at some distance from the bubble surface. This effect provides the mechanism for the emergence of two types of compound particles having the opposite polarity, which leads to the aggregation of such compound particles into fractal clusters. Based on experimental data, arguments in favor of the existence of the clusters composed of the ion-stabilized bubbles in aqueous electrolyte solutions are advanced. This paper provides theoretical grounds for the experimental results presented in the previous paper (part I) published in this journal.
Collapse
Affiliation(s)
- N F Bunkin
- A. M. Prokhorov General Physics Institute, Moscow, Vavilova 38 119991, Russia.
| | | |
Collapse
|
7
|
Bunkin NF, Shkirin AV, Ignatiev PS, Chaikov LL, Burkhanov IS, Starosvetskij AV. Nanobubble clusters of dissolved gas in aqueous solutions of electrolyte. I. Experimental proof. J Chem Phys 2012; 137:054706. [PMID: 22894370 DOI: 10.1063/1.4739528] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Results of experiments with dynamic light scattering, phase microscopy, and polarimetric scatterometry allow us to claim that long-living gas nanobubbles and the clusters composed of such nanobubbles are generated spontaneously in an aqueous solution of salt, saturated with dissolved gas (say, atmospheric air). The characteristic sizes of both nanobubbles and their clusters are found by solving the inverse problem of optical wave scattering in ionic solutions. These experimental results develop our earlier study reported by Bunkin et al. [J. Chem. Phys. 130, 134308 (2009)] and can be treated as evidence for the special role of ions in the generation and stabilization of gas nanobubbles.
Collapse
Affiliation(s)
- N F Bunkin
- A. M. Prokhorov General Physics Institute, Vavilova 38, Moscow 119991, Russia.
| | | | | | | | | | | |
Collapse
|
8
|
Bunkin NF, Kozlov VA, Ignat'ev PS, Suiazov NV, Shkirin AV, Atakhodzhaev IA. [Coefficient of refraction of water and aqueous solutions in the optical frequency range in the vicinity of naphione]. Biofizika 2012; 57:945-964. [PMID: 23272575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Within the present experimental working it has been shown that in the vicinity of naphione (ion-exchange membrane) the water refraction coefficient grows approximately by a factor of 1.1 in comparison with its value in a liquid. The refractive coefficient changes at the wavelength of about 50 microns. The effect of the refractive coefficient is measured by the pH value and the temperature of the liquid. In the experimental study of the "glycerin/water" mixture at different concentrations it has been found that the refractive coefficient may increase because naphione surface attracts the dipole of water clusters. This effect occurs due to the swelling of naphione in water and its surface takes a charge.
Collapse
|
9
|
Bunkin NF, Ninham BW, Babenko VA, Suyazov NV, Sychev AA. Role of dissolved gas in optical breakdown of water: differences between effects due to helium and other gases. J Phys Chem B 2010; 114:7743-52. [PMID: 20496876 DOI: 10.1021/jp101657f] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
It is shown that water contains defects in the form of heterogeneous optical breakdown centers. Long-living complexes composed of gas and liquid molecules may serve as nuclei for such centers. A new technique for removing dissolved gas from water is developed. It is based on a "helium washing" routine. The structure of helium-washed water is very different from that of water containing dissolved atmospheric gas. It is able to withstand higher optical intensities and temperatures of superheating compared with the nonprocessed ones. The characteristics of plasma spark and values of the breakdown thresholds for processed and nonprocessed samples are given.
Collapse
Affiliation(s)
- N F Bunkin
- A.M. Prokhorov General Physics Institute, Russian Academy of Sciences, ul. Vavilova, 38, 119991, Moscow, Russia.
| | | | | | | | | |
Collapse
|
10
|
Bunkin NF, Suyazov NV, Shkirin AV, Ignatiev PS, Indukaev KV. Nanoscale structure of dissolved air bubbles in water as studied by measuring the elements of the scattering matrix. J Chem Phys 2009; 130:134308. [PMID: 19355733 DOI: 10.1063/1.3095476] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Results of experiments with laser modulation interference microscopy and the Mueller-matrix scatterometry show that macroscopic scatterers of light waves are present in doubly distilled water free of external solid impurities. The experimental data can be interpreted using a computational model of micron-scale clusters composed of polydisperse air bubbles having effective radii of 70-90 nm. The fractal dimension of such clusters was evaluated as 2.4-2.8 and their concentration appeared to be approximately 10(6) cm(-3).
Collapse
Affiliation(s)
- N F Bunkin
- A. M. Prokhorov General Physics Institute, Russian Academy of Sciences, ul. Vavilova, 38, Moscow 119991, Russia.
| | | | | | | | | |
Collapse
|
11
|
Bunkin NF, Lobeyev AV, Lyakhov GA, Ninham BW. Mechanism of low-threshold hypersonic cavitation stimulated by broadband laser pump. Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics 1999; 60:1681-90. [PMID: 11969950 DOI: 10.1103/physreve.60.1681] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/1998] [Revised: 02/22/1999] [Indexed: 04/18/2023]
Abstract
A low threshold acoustic cavitation regime was observed for the excitation of hypersonic waves due to a stimulated Brillouin scattering (SBS) mechanism, when the optical pump lies within the uv frequency range. Cavitation occurs if the optical pump bandwidth Delta(+)>>Omega(0), where Omega(0) is the Stokes frequency shift (the hypersonic frequency). In the opposite case (Delta(+)<<Omega(0)), cavitation does not occur despite the fact that the hypersonic wave intensity is much higher. The effect is associated with the stimulation of a broad frequency spectrum of hypersonic pressure in a field provided by the broadband optical pump. In contrast, for a monochromatic optical pump, the hypersonic wave is of single-frequency character. Induction of cavitation at the low intensities of acoustic pressure is attributed to nanobubbles of fixed size that occur in the liquid. The resonant frequency of the nanobubbles coincides with the frequency of some spectral component of hypersound present in the broadband SBS process. That conclusion is reinforced by the further observation that at the same intensity of broadband pumping the cavitation vanishes after degassing the liquid. In parallel experiments on four-photon polarization Rayleigh wing spectroscopy, it was also demonstrated that spectral lines exist in ordinary (not degassed) water, which can be ascribed to resonances of radial vibrations of nanobubbles. Those lines are absent in the degassed water spectrum.
Collapse
Affiliation(s)
- N F Bunkin
- General Physics Institute of the Russian Academy of Sciences, Vavilova Street 38, 117942 Moscow, Russia.
| | | | | | | |
Collapse
|