active medium
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Author(s):  
Elham Asa ◽  
Rahil Janatifar ◽  
Seyedeh Saeideh Sahraei ◽  
Atefeh Verdi ◽  
Naser Kalhor

Background: Failed oocyte activation following intracytoplasmic sperm injection (ICSI) as a result of calcium deficiency is a major challenge. Objective: We compared the effect of cult-active medium (CAM) on ICSI outcomes in obstructive azoospermia cases. Materials and Methods: The present study was conducted with 152 ICSI cases, classified into CAM and control groups. The injected oocytes in the control group were cultured in the cleavage medium, while in the artificial oocyte activation group, oocytes were chemically activated through exposure to 200 µL of CAM for 15 min. Fertilization and cleavage rates, quality of embryos, and biochemical pregnancy and live birth rates were assessed in both groups. Results: There were significant differences between the groups in terms of fertilization and cleavage rates after using the CAM in the percutaneous epididymal sperm aspiration (PESA) subgroup (p = 0.05, p ≤ 0.001) and in the testicular sperm extraction subgroup (p = 0.02, p = 0.04), compared to their control groups. Also, the pregnancy rate was significantly higher in the PESA-CAM subgroup (p = 0.03). The PESA-CAM subgroup demonstrated a significant difference in embryo quality after ICSI (p = 0.04). Unsuccessful embryo transfer and abortion were lower in both subgroups compared to the control groups, but this difference was not significant. Surprisingly, live birth rate was higher in the PESA-CAM subgroup (p = 0.03). Conclusion: CAM treatment could improve fertilization and cleavage rates in obstructive azoospermia participants. It had a significant effect on embryo quality, and pregnancy and live birth rates in PESA cases. Key words: Calcium ionophore, Obstructive azoospermia, Fertilization, ICSI.


Author(s):  
Е.И. Гиршова ◽  
Е.П. Микитчук ◽  
А.В. Белоновский ◽  
К.М. Морозов

A hybrid material was studied, consisting of polydimethylsiloxane and silver nanoparticles distributed throughout its volume, its optical and thermodynamic characteristics were calculated for different volume fractions of silver content. It is theoretically shown that this material with a volume fraction of silver of about 30% can be used as an active medium for an optoacoustic transducer with an operating frequency range of about 10 MHz.


2021 ◽  
Author(s):  
Ilya Zyatikov ◽  
Valery Losev ◽  
Vladimir Prokopev

Author(s):  
Dmitrii Kolotkov ◽  
Dmitrii Zavershinskii ◽  
Valery M Nakariakov

Abstract The presence and interplay of continuous cooling and heating processes maintaining the corona of the Sun at the observed one million K temperature were recently understood to have crucial effects on the dynamics and stability of magnetoacoustic waves. These essentially compressive waves perturb the coronal thermal equilibrium, leading to the phenomenon of a wave-induced thermal misbalance. Representing an additional natural mechanism for the exchange of energy between the plasma and the wave, thermal misbalance makes the corona an active medium for magnetoacoustic waves, so that the wave can not only lose but also gain energy from the coronal heating source (similarly to burning gases, lasers and masers). We review recent achievements in this newly emerging research field, focussing on the effects that slow-mode magnetoacoustic waves experience as a back-reaction of this perturbed coronal thermal equilibrium. The new effects include enhanced frequency-dependent damping or amplification of slow waves, and effective, not associated with the coronal plasma non-uniformity, dispersion. We also discuss the possibility to probe the unknown coronal heating function by observations of slow waves and linear theory of thermal instabilities. The manifold of the new properties that slow waves acquire from a thermodynamically active nature of the solar corona indicate a clear need for accounting for the effects of combined coronal heating/cooling processes not only for traditional problems of the formation and evolution of prominences and coronal rain, but also for an adequate modelling and interpretation of magnetohydrodynamic waves.


2021 ◽  
Vol 2094 (2) ◽  
pp. 022034
Author(s):  
E E Popov ◽  
A A Sergeev ◽  
A P Pogoda ◽  
V M Petrov ◽  
A S Boreysho

Abstract We demonstrate electro-optic Q-switched solid state laser with Cr:LiSAF active medium. A single 50 ns pulse with 14 mJ of output energy is demonstrated. Simultaneous generation of several peaks with a step of 1.4 nm within the spectrum envelope with a full width at half maximum of 10.3 nm is demonstrated. For an electro-optic Q-switched mode a Pockels cell is used. Demonstrated laser can be used in differential absorption lidar systems.


2021 ◽  
Vol 23 (2) ◽  
pp. 45-47
Author(s):  
A.A. Sherniyozov ◽  
Sh.D. Payziyev ◽  
F.A. Shermatova ◽  
Sh.A. Begimkulov ◽  
A.G. Qahhorov ◽  
...  

Here we present the results of our study on the feasibility of a multi-pass pumping scheme in solar lasers. A secondary concentrator has been developed to ensure the multiple passage of solar photons through the active medium. When using a multi-pass pumping scheme, an increase of 12.5% in the luminescence spectra of Nd:YAG is observed in the vicinity of the lasing line at a wavelength of 1064 nm


2021 ◽  
Vol 22 (3) ◽  
pp. 426-431
Author(s):  
Z.M. Mykytyuk ◽  
M.V. Vistak ◽  
I.T. Kogut ◽  
V.V. Petryshak

The paper presents the results of the study of the parameters of the highly sensitive active medium of the NO2 sensor based on a cholesterol-nematic mixture with an admixture of carbon nanotubes. The dependence of the change in the wavelength of the two transmission minima on the NO2 concentration for cholesterol-nematic mixture with single-walled, double-walled and multi-walled nanotubes at different concentrations of nanotubes and two concentrations of nematically liquid crystal 5CB were obtained. It is established that by changing the ratio between the concentrations of nanotubes and nematic liquid crystals, it is possible to obtain mixtures that have the maximum spectral sensitivity coefficient in a given range of gas concentration.


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