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Background The gonadotropin-releasing hormone (GnRH) antagonist protocol is advantageous given that it can avoid severe ovarian hyperstimulation syndrome (OHSS), especially for patients with polycystic ovary syndrome (PCOS). Basic and clinical evidence has shown that a threshold of luteinizing hormone (LH) stimulation is required for adequate follicular development and oocyte maturation. Ultra-low or high levels of LH are detrimental to pregnancy outcomes. We previously demonstrated that LH could be an indicator for the timing and dosage of antagonist administration in a retrospective study. Methods/design In this randomized, single-center, non-inferiority trial, we aim to test the hypothesis that there is no significant difference in cumulative ongoing pregnancy rates between PCOS patients stimulated with LH-based flexible protocol versus traditional flexible GnRH antagonist protocol. The primary efficacy endpoint will be the cumulative ongoing pregnancy rate per cycle. The secondary outcomes will be clinical pregnancy rate, cancelation rate, serious OHSS rate, and cost-efficiency. The cumulative ongoing pregnancy rate per cycle in PCOS women was 80%. Considering that a non-inferiority threshold should retain 80% of the clinical effect of a control treatment, a minimal clinical difference of 16% (two-sided: α, 2.5%; β, 20%) and a total of 196 patients were needed. Anticipating a 10% dropout rate, the total number of patients required was 216. Discussion The results of this study will provide evidence for the efficacy and safety of the LH-based flexible GnRH antagonist protocol in PCOS patients. Moreover, it evaluates the cost-efficiency of both protocols. Trial registration Chinese Clinical Trial Registry ChiCTR1800018129. Date assigned: 31 August 2018. Protocol version: 1.0 (18 July 2017)

RESEARCH QUESTION: Granulosa cells (GCs) surrounding oocytes are crucial for follicular growth, oocyte development, ovulation, and luteinization under the dynamic co-stimulation of follicle stimulating hormone (FSH) and luteinizing hormone (LH). This study aimed to investigate the effect of LH levels on GCs in preovulatory follicles under gonadotropin releasing hormone antagonist-based ovarian stimulation. In vitro experiments were also conducted to study the direct effect of LH on GCs. METHODS: Twelve infertile women were divided into low (L), medium (M), and high (H) LH groups according to their serum LH levels during ovarian stimulation. RNA-sequencing (RNA-seq) was conducted to examine the transcriptome profiles of GCs obtained from the above patients during the oocyte retrieval. The activity of mitochondrial dehydrogenase was measured under the stimulation of recombinant LH (rLH) concentration gradient combined with recombinant FSH. The ultrastructures of subcellular organelles were observed. RESULTS: Bioinformatic analyses showed that compared with the M group, molecule and pathway changes in the L group and in the H group were similar. In cultured GCs, both insufficient and excessive rLH impaired the activity of mitochondrial dehydrogenase. With the medium rLH concentration, numerous cell connections and abundant mitochondria and liposomes were observed. Compared with the medium concentration, GCs showed smaller and rounder mitochondria, more autophagosomes, and massive organelles damages with excessive rLH, and swollen, circular, or forked mitochondria were observed with inadequate rLH. CONCLUSIONS: RNA-seq provided a novel spectrum of transcriptome characteristics of GCs potentially affected by serum LH levels during ovarian stimulation. In vitro, rLH could directly affect GCs at the subcellular level. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10815-021-02066-8.

Based on the mode-coupling method, numerical analysis is presented to demonstrate the influence of ripple taper on coupling modes on the frequency response in a coaxial Bragg structure. Results show that the interval between the band-gaps of the competing mode and the desired working mode is narrowed by use of a positive taper, but is expanded if a negative taper is employed, and the influence of the negative taper is more obviously advantage than the positive taper. The residual side-lobes of the frequency response on coupling modes can be effectively suppressed by employing the windowing-function technique. These characteristics of a tapered coaxial Bragg structure are favorable to improvement of the performance as a reflector or a filter in its application, also favorable to the mode selectivity and further weaken the excitation of unwanted spurious modes.