Clinical Application of Double Ovulation Stimulation in Patients with Diminished Ovarian Reserve and Asynchronous Follicular Development Undergoing Assisted Reproduction Technology

Objective This study aimed to compare the clinical effects of double ovulation stimulation(DouStim)applied during the follicular and luteal phases with the antagonist protocol in patients with diminished ovarian reserve(DOR)and asynchronous follicular development undergoing assisted reproductive technology(ART).Methods The clinical data of patients with DOR and asynchronous follicular development receiving ART from January 2020 to December 2021 were retrospectively analyzed.The patients were divided into two groups according to their ovulation stimulation protocol:DouStim group(n=30)and antagonist group(n=62).Assisted reproduction and clinical pregnancy outcomes were compared between the two groups.Results In the DouStim group,the number of oocytes retrieved,metaphase II(MII)oocytes,two-pronuclei(2PN),day 3(D3)embryos,D3 high-quality embryos as well as blastocyst formation,implantation,and human chorionic gonadotropin-positive rates were significantly greater than those in the antagonist group(all P<0.05).No significant differences were found in MII,fertilization,or continued pregnancy rates at the first frozen embryo transfer(FET),in-vitro fertilization(IVF)cancellation,or early medical abortion rates between the groups(all P>0.05).Except for the early medical abortion rate,the DouStim group generally had favorable outcomes.In the DouStim group,the dosage and duration of gonadotropin and the fertilization rate were significantly greater in the first ovulation stimulation induction than in the second ovulation stimulation induction(P<0.05).Conclusion The DouStim protocol efficiently and economically obtained more mature oocytes and high-quality embryos for patients with DOR and asynchronous follicular development.

Characteristics and suppression of beam distortion in a high repetition rate nanosecond stimulated Brillouin scattering phase conjugation mirror

The stimulated Brillouin scattering phase conjugation mirror (SBS-PCM) based on liquid media is widely used in high-power laser systems due to its robust thermal load capacity, high energy conversion efficiency and improved beam quality. Nevertheless, with an increase in the pump repetition rate, thermally-induced blooming and optical breakdown can emerge, leading to distortions in the Stokes beam. In this study, we delved into the thermal effects in liquid SBS-PCMs employing hydrodynamic analysis, establishing a relationship between beam profile distortion and the thermal convection field. We calculated the temperature and convection velocity distribution based on the pump light parameters and recorded the corresponding beam profiles. The intensities of the beam profiles were modulated in alignment with the convection directions, reaching a velocity peak of 2.85 mm/s at a pump pulse repetition rate of 250 Hz. The residual sum of squares (RSS) was employed to quantify the extent of beam profile distortion relative to a Gaussian distribution. The RSS escalated to 7.8, in contrast to 0.7 of the pump light at a pump pulse repetition rate of 500 Hz. By suppressing thermal convection using a high-viscosity medium, we effectively mitigated beam distortion. The RSS was reduced to 0.7 at a pump pulse repetition rate of 500 Hz, coinciding with a twentyfold increase in viscosity, thereby enhancing the beam quality. By integrating hydrodynamic analysis, we elucidated and mitigated distortion with targeted solutions. Our research offers an interdisciplinary perspective on studying thermal effects and contributes to the application of SBS-PCMs in high-repetition-rate laser systems by unveiling the mechanism of photothermal effects.