Synchrotron X-ray nano computed tomography was used to investigate the microstructural evolution during co-sintering of multi-layer ceramic capacitors (MLCC) consisting of Ni electrodes and BaTiO3 ...dielectric layers stacked alternately. As the electrode thickness reduced to submicron at the scale of a few particle diameters, the process produced the defect of inner electrode leading to capacitance loss. The discontinuous electrode region contained round holes and irregularly-shaped channels. The formation of discontinuity was associated with the increase of characteristic length of heterogeneous electrode structure, i.e., the coarsening occurred. The evolution of electrode morphology by surface/interface diffusion caused the breakup of ligament between two holes driven by instability induced by surface tension and stress. The ligament pinch-off inevitably generated sharp points which might enhance the local electric field bringing about the dielectric breakdown. A model was presented to explain the formation of defect from the heterogeneous particles packing in the electrode layer.
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Background
Gonadotropins induce follicular development that leads to ovulation and luteinization. In women, the level of gonadotropins, along with the expression of their receptors, changes ...dynamically throughout the menstrual cycle. This study aimed to clarify the mechanisms underlying these phenomena.
Methods
The literature was reviewed, including that published by the authors.
Main findings (Results)
Follicle‐stimulating hormone receptor expression in the granulosa cells was induced by androgens that were derived from growth differentiation factor‐9‐stimulated theca cells. In the theca cells, luteinizing hormone receptor (LHR) expression was noted from their appearance. In the granulosa cells, follicle‐stimulating hormone (FSH) stimulation was essential for LHR expression. However, FSH alone was not sufficient to respond to the luteinizing hormone (LH) surge for oocyte maturation, ovulation, and subsequent luteinization. To achieve these stages, various local factors that were derived from the granulosa and theca cells in response to FSH and LH stimulation had to work synergistically in an autocrine/paracrine manner to strongly induce LHR expression. Following the LH surge, the LHR expression decreased markedly; miRNAs were involved in this transient LHR downregulation. Following ovulation, LHR expression drastically increased again toward luteinization.
Conclusion
The expression of gonadotropin receptors is controlled by sophisticated and complicated systems; a breakdown of this system could lead to ovulation disorders.
In females, level of gonadotropins, along with the expression of their receptors, dynamically changes throughout the menstrual cycle. Various local factors derived from the granulosa and theca cells in response to FSH and LH stimulation, have to work in coordination in an autocrine/paracrine manner to maintain normal menstrual cycle.
In order to obtain material design guidelines for next-generation multilayer ceramic capacitors (MLCCs) from the viewpoint of polarization behavior, we investigated the changes in polarization ...behavior with AC- and Uni-poling treatment using (Ba,Ca)(Ti,Zr)O3-based MLCC samples in which a part of the BaTiO3 in the core was modified with Ca and Zr. Comparisons with DC-aging measurements confirmed that the AC- and Uni-poling treated samples clearly showed a unique phenomenon in which the domain wall of the (Ba,Ca)(Ti,Zr)O3-based core phase moves faster than that of the BaTiO3-based core phase. AC- and Uni-poling treatments are expected to be useful tools for evaluating the relationship between more detailed microstructure and polarization behavior of dielectric materials.
To obtain guidelines for the microstructure design of BaTiO3-based multilayer ceramic capacitors from the viewpoint of polarization behavior, the effects of AC- and Uni-poling treatments were ...examined using intentionally grain-growth samples. For purposes of comparison, the DC-aging characteristics of each sample were also examined. From the results of the polarization behavior induced by AC- and Uni-poling treatments, it was confirmed that changes in the core–shell structure, grain size, and oxygen vacancy concentration of the dielectrics strongly affected the domain wall pinning. In comparison with DC-aging characteristics, AC- and Uni-poling treatments are also expected to be effective tools for clarifying the relationships among more detailed microstructure and polarization behaviors of dielectrics.
Purpose
Since 1986, the Japan Society of Obstetrics and Gynecology assisted reproductive technology (ART) registry system has collected data on national ART use and outcomes trends in Japan. Herein, ...we describe the characteristics and outcomes of ART cycles registered during 2020 and compare the results with those from 2019.
Methods and Results
In 2020, 621 ART facilities participated in the registration. The total number of registered cycles was 449 900, and there were 60 381 live births, which decreased from the previous year (1.79% and 0.36% decrease, respectively). The number of freeze‐all in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) cycles increased in 2020, and the number of neonates born was 2282 for IVF‐embryo transfer (ET) cycles and 2596 for ICSI cycles, which had decreased from the previous year. Frozen–thawed ET (FET) cycles had slightly increased from 2019 (0.04%). In 2020, 215 285 FET cycles were conducted, resulting in 76 196 pregnancies and 55 503 neonates. Single ET was performed in 81.6% of fresh transfers and 85.1% of frozen–thawed cycles, respectively, resulting in over 97% singleton pregnancies/livebirths rates.
Conclusion
Despite the COVID‐19 pandemic during 2020, the overall number of ART cycles and neonates born demonstrated only a slight decrease in 2020 compared with 2019.
Despite the COVID‐19 pandemic during 2020, the overall number of ART cycles and neonates born demonstrated only a slight decrease in 2020 compared with 2019.
Heterotopic pregnancy (HP) is a rare but life‐threatening disease. We report a rare case of HP that occurred after single embryo transfer (SET) with spontaneous natural pregnancy possibly due to ...sexual intercourse (SI) during assisted reproductive technology treatment and reviewed previous reports. A 39‐year‐old woman at 7 weeks 5 days' gestation with anti‐sperm antibody who underwent a single frozen–thawed embryo transfer in her natural cycle presented with lower abdominal pain and vaginal bleeding. She had several SIs before the day of SET. A viable intrauterine fetus and an extrauterine mass at the right adnexa were detected on transvaginal ultrasonography. An emergent laparoscopic surgery showed a swollen right fallopian tube, and right salpingectomy was performed. Unfortunately, intrauterine fetal death was diagnosed at 19 weeks' gestation. In conclusion, the possibility of HP should be considered in patients with SIs around the day of SET.
Purpose
The Japan Society of Obstetrics and Gynecology records online annual cycle‐based information for assisted reproductive technology (ART). This report presents the characteristics and treatment ...outcomes of ART cycles registered during 2019.
Methods
The Japanese ART registry includes cycle‐specific information from 619 participating facilities, including treatment and pregnancy outcomes. Descriptive analyses were conducted for cycles registered during 2019.
Results
In 2019, 458 101 treatment cycles and 60 598 neonates were reported, both of which increased from 2018. The number of fresh cycles, including in vitro fertilization and intracytoplasmic sperm injection, decreased, while frozen‐thawed embryo transfer (ET) cycles increased. The mean maternal age was 37.9 years (standard deviation ± 4.7). Of 239 348 oocyte retrievals, 123 690 (51.7%) involved freeze‐all‐embryos cycles; fresh ET was performed in 41 831 cycles (a decreasing trend since 2015). In 2019, there were 211 597 frozen‐thawed ET cycles, resulting in 74 882 pregnancies and 54 168 neonates born. Single ET was performed in 82.6% of fresh transfers and 85.1% of frozen‐thawed cycles, with singleton live birth rates of 97.3% for both.
Conclusions
The number of fresh cycles decreased but frozen cycles increased in 2019. Single ET was performed in >80% of cases, and the proportion of babies born from frozen‐thawed ET increased.
The number of fresh cycles decreased but frozen cycles increased in 2019. Single ET was performed in >80% of cases, and the proportion of babies born from frozen‐thawed ET increased.
Purpose
To create and evaluate a machine‐learning model for YOLOv3 that can simultaneously perform morphological evaluation and tracking in a short time, which can be adapted to video data under an ...inverted microscope.
Methods
Japanese patients who underwent intracytoplasmic sperm injection at the Jikei University School of Medicine and Keiai Reproductive and Endosurgical Clinic from January 2019 to March 2020 were included. An AI model that simultaneously performs morphological assessment and tracking was created and its performance was evaluated.
Results
For morphological assessment, the sensitivity and positive predictive value (PPV) of this model for abnormal sperm were 0.881 and 0.853, respectively. The sensitivity and PPV for normal sperm were 0.794 and 0.689, respectively. For tracking performance, among the 51 objects, 40 (78.4%) were mostly tracked, 11 (21.6%) were partially tracked, and 0 (0%) were mostly lost.
Conclusions
This study showed that evaluating sperm morphology while tracking in a single model is possible by training YOLO v3. This model could acquire time‐series data of one sperm, which will assist in acquiring and annotating sperm image data.
Simultaneous morphological evaluation and tracking using AI enabled us to obtain time‐series data of a single sperm, which facilitated the acquisition and annotation of sperm image data.
Purpose
To provide information about the relationship between follow‐up period and follicular development in patients with infertility due to premature ovarian insufficiency (POI) who are undergoing ...hormone replacement therapy (HRT). It is necessary to detect follicle development for artificial insemination or in vitro fertilization.
Methods
This retrospective cohort study was conducted at a university hospital in Tokyo, Japan, from April 2014 to February 2019 in 20 patients follicular development group, 11 women (55%); non‐follicular development group, 9 women (45%) with POI; their follicular development was followed up weekly. Background characteristics, including age, follicle‐stimulating hormone (FSH) and anti‐Mullerian hormone levels (AMH), the period from the last spontaneous menstruation to hormone replacement therapy initiation, and follow‐up period during HRT were investigated. The period without follicular development was tabulated, and the subsequent cumulative follicular development detection rate was calculated.
Results
At least 1‐year follow‐up, the cumulative follicular development rate was 70%; follicular development was observed with a probability of 49.1% at 3 months, 33.4% at 6 months, and 8.3% at 12 months in the follow‐up period.
Conclusions
The results show that the longer the non‐follicle development period, the lower the probability of subsequent follicular development in patients with POI during HRT.
Cumulative follicular development rate during follow‐up during HRT. At 1‐year follow‐up, the cumulative follicular development rate was 70%; follicular development was observed with a probability of 49.1% at 3 months, 33.4% at 6 months, and 8.3% at 12 months in the follow‐up period.
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